CN103107562A - Switch charging circuit and power management system - Google Patents

Abstract

The invention discloses a switch charging circuit and a power management system. The switch charging circuit comprises a system power end, a battery end, a reference power end, a charging enable signal end, a battery-powered judgment signal end and a switch charging module. The switch charging module comprises a switch charging control logic module, a charging voltage control module, a charging current control module, a pulse width control module and a switch power level. The power management system comprises a first voltage comparison module, a second voltage comparison module, a logic control module, a first voltage maintenance module, a second voltage maintenance module, a first switch unit, a second switch unit, the reference power end, an external power input end, the system power end, the battery end, the switch charging module and a first voltage conversion module. The switch charging circuit and the power management system are simple in implementation and high in charging efficiency.

Description

A kind of switched charge circuit and power-supply management system

Technical field

The present invention relates to the power management techniques field, particularly relate to a kind of switched charge circuit and power-supply management system.

Background technology

Day by day universal along with portable type electronic product, the function of electronic equipment constantly strengthens and is abundant gradually, makes electronic product power consumption increase, and the power management techniques that needs portable electric appts is constantly progressive adapts to the product power consumption with more newly arriving.

Present portable electric appts adopts lithium battery power supply usually, has simultaneously USB interface and AC adapter interface.Therefore need to select correct power supply to originate to system power supply in different input powers according to situation and the applicable cases of different input powers, again lithium battery be carried out Charge Management simultaneously.

In actual applications, the driving force difference of various different input powers is very large.Such as, be all the AC adapter of 5V, in order to satisfy different cost requirements, driving force can be from 200mA to 2A more than; And the driving force of usb interface connector also has the plurality of specifications such as 100mA or 500mA, and up-to-date USB3.0 specification requirement is 900mA.Along with the issue of handpiece adapter interface national standard, increasing AC adapter is also made USB plug, so applicable cases is more complicated simultaneously.

Existing charging management chip or power management chip generally adopt pin that the size of current limliting is set, and need main control chip to go to detect in real time the situation of external power source access by input/output interface, and resolution are that adapter inserts or USB inserts.If the adapter input does not just need to arrange current limliting, if find that USB inserts, change the current limliting setting by main control chip Output Interface Control power supply chip pin, namely rely on Master control chip to judge the situation of outside access power supply, then the size of current limliting is set by the universal input/output interface of main control chip.

Such control mode, power supply chip self does not judge that input power has great driving force actually, and need to rely on main control chip to judge the situation of outside access power supply, the size of current limliting is set by the universal input/output interface of main control chip again, makes all become unusual complexity of the software and hardware of system.Because need main control chip to detect in real time the external power source situation, this just needs modification software, the driver of main control chip.Need simultaneously to control by output pin the setting that external circuit changes current limliting, so just need to increase outside hardware circuit.Therefore need hardware and software engineer coordinated, could realize, and need reliability and the correctness of the work of plenty of time checking whole system; Main control chip needs to detect in real time simultaneously, can take the main control chip cpu resource, lowers efficiency.

Simultaneously the capacity due to lithium battery constantly becomes large, and in order to guarantee the charging interval in tolerance interval, so charging current also constantly increases thereupon.Traditional linear charger because efficient is very low, causes the chip heating serious, therefore is difficult to satisfy the demand of high-capacity lithium battery charging.

Summary of the invention

The object of the present invention is to provide a kind of switched charge circuit and power-supply management system, its solved of the prior art need hardware and software in conjunction with and cause implementing complicated problem, and adopt the linear-charging mode to cause the problem of chip heating.

Be a kind of switched charge circuit of realizing that the object of the invention provides, comprise system power supply end, battery-end, reference power source end, charging enable signal end and powered battery judgement signal end, also comprise the switched charge module, described switched charge module comprises switched charge control logic module, charging voltage control module, charging current control module, pulse width control module and switch power level; Described switched charge control logic module, described charging voltage control module, described pulse width control module all are connected with described charging enable signal end, described powered battery judgement signal end; Described charging voltage control module also is connected with described battery-end, reference power source end, and output charging voltage error signal is to described pulse width modulation module; Described pulse width modulation module output pulse width modulation signal is used for described charging voltage error signal is converted to pulse width modulating signal to described switched charge control logic module; Described switch power level also is connected with described battery-end, described system power supply end, comprise high-side power switch pipe, low-side power switch pipe and power inductance, the conducting pulsewidth of described high-side power switch pipe and described low-side power switch pipe determines the size of charging current; Described charging current control module is connected with described charging enable signal end, described powered battery judgement signal end, described reference power source end, receive the current signal of the power inductance feedback of described switch power level, output battery charging current error signal is to described pulse width modulation module; Described switched charge control logic module also is connected with described switch power level, is used for controlling according to described pulse width modulating signal the conducting pulsewidth of described high-side power switch pipe and described low-side power switch pipe, and then regulates charging current.

Wherein, described charging voltage control module comprises the first differential amplifier, the first resistance and the second resistance; One end of described the first resistance is connected with described battery-end, the other end of described the first resistance be connected an end of the second resistance and connect, the other end ground connection of described the second resistance; Tie point between described the first resistance and described the second resistance is connected with the positive input terminal of described the first differential amplifier; The negative input end of described the first differential amplifier is connected with described reference power source end; The output output charging voltage error signal of described the first differential amplifier.

Wherein, described charging current control module comprises the second differential amplifier; The positive input terminal access of described the second differential amplifier is by the current signal of the power inductance feedback of described switch power level, the negative input end of described the second differential amplifier is connected with described reference power source, the output output battery charging current error signal of described the second differential amplification.

Wherein, described pulse width modulation module comprises the 3rd differential amplifier, the first comparator, superpositing unit, the second electric capacity, the 3rd electric capacity, the 4th electric capacity, the 3rd resistance, the 4th resistance and the 5th resistance; Described superpositing unit is with described charging voltage error signal, the stack of described battery charging current error signal; One end of described the 3rd resistance is connected with the output of described superpositing unit, and the other end of described the 3rd resistance is connected with the negative input end of described the 3rd differential amplifier, and the positive input terminal of described the 3rd differential amplifier is connected with described reference power source end; One end of described the second electric capacity is connected with the output of described superpositing unit, and the other end of described the second electric capacity is connected with an end of described the 4th resistance, and the other end of described the 4th resistance is connected with the negative input end of described the 3rd differential amplifier; One end of described the 5th resistance is connected with the negative input end of described the 3rd differential amplifier, and the other end of described the 5th resistance is connected with an end of described the 3rd electric capacity, and the other end of described the 3rd electric capacity is connected with the output of described the 3rd differential amplifier; One end of described the 4th electric capacity is connected with the negative input end of described the 3rd differential amplifier, and the other end is connected with the output of described the 3rd differential amplifier; The output of described the 3rd differential amplifier is connected with the negative input end of described the first comparator, the positive input terminal input triangular wave of described the first comparator; The output output pulse width modulation signal of described the first comparator.

Wherein, described switched charge control logic module comprises power tube control logic unit, controlled timer and the second comparator or digital to analog converter; Described the second comparator or digital to analog converter are connected with described reference power source end, described charging Enable Pin be connected the power inductance of switch power level and connect, output current data signal or electric current comparison signal are to described controlled timer; Described controlled timer is connected with described charging enable signal end, and receive clock frequency signal and current data signal or electric current comparison signal, export the charging timeout signal to described power tube control logic unit simultaneously; Described power tube logic control element receives charging enable signal, powered battery judgement signal, described pulse width modulating signal and described charging timeout signal, output high-side power switch pipe controls signal to described high-side power switch pipe, and output low-side power switch pipe controls signal to described low-side power switch pipe.

Wherein, described power tube control logic unit comprise trigger, first and door, second with door, the 3rd with door, first or, second or door, the first inverter, the second inverter, the 3rd inverter, the 4th inverter, the first driving stage, the second driving stage.after described powered battery judgement signal is anti-phase through the 4th inverter with described charging enable signal and described charging timeout signal as described first with three input end signals of door, first with output end signal and the described clock frequency signal of door as described second with two input end signals, described first with the door output end signal anti-phase through the first inverter after with described pulse width modulating signal as described first or the door two input end signals, described second is connected to the S end of described trigger with the output end signal of door, described first or the output end signal of door be connected to the R end of described trigger.The Q end signal of described trigger after the 3rd inverter is anti-phase with the output end signal of described the second driving stage as described second or two input end signals of door, described second or the output end signal of door be connected to the input of described the first driving stage, the output end signal of described the first driving stage is described high-side power switch management and control signal processed, is connected to described high-side power switch pipe.The Q end signal of described trigger after the second inverter is anti-phase with described first with the output end signal of door and the output end signal of the first driving stage as the described the 3rd with three input end signals of door, the described the 3rd is connected to the input of described the second driving stage with the output end signal of door, the output end signal of described the second driving stage is described low-side power switch management and control signal processed, is connected to described low-side power switch pipe.

Wherein, described controlled timer comprises two above frequency dividers and multiselect one MUX and timer; The input of described plural frequency divider all receives described clock frequency signal, the output of described frequency divider is connected with described multiselect one MUX, and the divide ratio of described plural frequency divider is for making the ascending series of equal difference with the inverse of frequency divider number; Multiselect one MUX also receives described current data signal or described electric current comparison signal, and output timer clock frequency is to described timer; Described timer also is connected with described charging Enable Pin.

Wherein, described high-side power switch Guan Weiyi P channel MOS tube, described low-side power switch Guan Weiyi N-channel MOS pipe; The grid of described P channel MOS tube be connected the grid of N-channel MOS pipe and be connected with described switched charge control logic; The source electrode of described P channel MOS tube is connected with described system power supply end, and the drain electrode of described P channel MOS tube is connected with the drain electrode of described N-channel MOS pipe, the source ground of described N-channel MOS pipe; Described P channel MOS tube be connected the tie point of N-channel MOS pipe and be connected with an end of described power inductance, the other end of power inductance is connected with described battery-end.

The present invention also discloses a kind of power-supply management system, comprise that the first voltage comparison module, second voltage comparison module, Logic control module, the first voltage keeps module, second voltage and keep module, the first switch element, second switch unit, reference power source end, external power source input, system power supply end, battery-end, also comprise foregoing switched charge module and the first voltage transformation module; Described switched charge module is connected with described system power supply end, described reference power source end, described battery-end, receives by the charging enable signal of described Logic control module output with by the powered battery judgement signal of described second voltage comparison module output and by the second voltage that described second voltage is kept module output and keeps signal; Described the first voltage transformation module and described system power supply end be connected the reference power source end and be connected, receive by the external power source of described Logic control module output and select signal, output is connected with described the first switch element.

Wherein, also comprise the linear-charging module, described linear-charging module and described battery-end, described reference power source end and be connected the second switch unit and be connected.

Wherein, also comprise the first current limliting module; Described the first current limliting module comprises the 6th differential amplifier, the positive input terminal access of described the 6th differential amplifier is by the current signal of described external power source input feedback, negative input end is connected with described reference power source end, and output is connected with described the first switch element.

Wherein, also comprise the second current limliting module, described the second current limliting module comprises the 7th differential amplifier, and the positive input terminal access of described the 7th differential amplifier is by the current signal of described battery-end feedback, negative input end is connected with described reference power source end, and output is connected with described second switch unit.

Wherein, described the first switch element comprises on the first switching tube and first and draws priviledge module; Described the first switching tube is a PMOS pipe or PNP pipe; Draw priviledge module to comprise the 3rd PMOS pipe, the 4th PMOS pipe, the 5th PMOS pipe and a current source that points to ground on described first; The output that described the first voltage is kept the output of module, described the first voltage transformation module be connected the output of current limliting module and be connected with the grid of described the 3rd PMOS pipe, the grid of the 4th PMOS pipe and the grid of the 5th PMOS pipe respectively; Be connected to the base stage of grid or a PNP pipe of a described PMOS pipe after the drain electrode short circuit of the drain electrode of the drain electrode of described the 3rd PMOS pipe, the 4th PMOS pipe and the 5th PMOS pipe as output, and be connected the outflow of bus current end ground connection of described current source with the electric current inflow end of described current source.

Wherein, comprise that also tertiary voltage comparison module, second voltage modular converter, tertiary voltage keep module, the 3rd switch element, USB current limliting module, VBUS input; Described tertiary voltage comparison module is connected with described VBUS input, described battery-end, and output VBUS useful signal is to described Logic control module; Described tertiary voltage is kept module and is connected with described VBUS input, described reference power source end, and the VBUS that receives by described Logic control module output selects signal, and the output tertiary voltage is kept signal to described the 3rd switch element; Described second voltage modular converter is connected with described system power supply end, reference power source end, and the VBUS that receives by described Logic control module output selects signal, and output second voltage switching signal is to described the 3rd switch element; The 3rd switch element also is connected with described VBUS input, system power supply end.

the invention has the beneficial effects as follows: a kind of switched charge circuit provided by the invention and power-supply management system, by the charging voltage control module being set according to the voltage signal of the charging enable signal that receives and powered battery judgement signal and battery-end, output charging voltage error signal is to described pulse width modulation module, described pulse width modulation module is according to the charging enable signal, powered battery judgement signal and described charging error signal output pulse width modulation signal, described switched charge control logic is adjusted the high-side power switch pipe of switch power level and the conducting pulsewidth of low-side power switch pipe according to described pulse width modulating signal again, and then adjusting charging current, realized regulating charging current according to the situation of multiple power supplies input, in the time can carrying out large current charge to battery-end, increase charging current, solved that large current charge is carried out in simple linear-charging and the problem that causes chip heating, and the employing hardware that the application's technical scheme is simple, structure understands, implement simple, can not occur due to needs software, combination of hardware and the problem of the enforcement complexity that causes.

Description of drawings

Fig. 1 is the circuit structure diagram of switched charge circuit of the present invention;

Fig. 2 is the circuit diagram of charging voltage control module of the present invention;

Fig. 3 is the circuit diagram of charging current control module of the present invention;

Fig. 4 is the circuit diagram of pulse width modulation module of the present invention;

Fig. 5 is the circuit structure diagram of switched charge control logic module of the present invention;

Fig. 6 is the circuit diagram of controlled timer of the present invention;

Fig. 7 is the circuit diagram of power tube logic control element;

Fig. 8 is the circuit structure diagram of the power-supply management system in embodiments of the invention two;

Fig. 9 is the circuit diagram that the first voltage of the present invention is kept module;

Figure 10 is the circuit diagram of the first voltage transformation module of the present invention;

Figure 11 is the circuit diagram of the pulse width modulation module in embodiments of the invention two;

Figure 12 is the circuit structure diagram of the power-supply management system in embodiments of the invention three;

Figure 13 is the circuit diagram of the first current limliting module of the present invention;

Figure 14 is the annexation figure of the first switch element of the present invention and the module that is attached thereto;

Figure 15 is the circuit diagram that draws priviledge module on of the present invention;

Figure 16 is the circuit structure diagram of the power-supply management system in embodiments of the invention four.

Embodiment

In order to make purpose of the present invention, technical scheme and advantage clearer, below in conjunction with drawings and Examples, a kind of switched charge circuit of the present invention and power-supply management system are further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, is not intended to limit the present invention.

Embodiment one

For the convenience of describing, external power source input ACIN is labeled as ACIN, battery-end BAT is labeled as BAT, and system power supply end SYS is labeled as SYS, and reference power source end REF is labeled as REF.Correspondingly, the input power terminal voltage signal is labeled as V _ACIN, battery-end BAT voltage signal is labeled as V _BAT, system power supply end SYS voltage signal is labeled as V _SYS, reference power source end REF voltage signal is labeled as V _REF

As a kind of embodiment, a kind of switched charge circuit provided by the invention comprises system power supply end SYS, battery-end BAT, reference power source end REF, charging enable signal end and powered battery judgement signal end, switched charge module.

Referring to Fig. 1, described switched charge module comprises switched charge control logic module, charging voltage control module, charging current control module, pulse width control module and switch power level.

Described charging voltage control module is connected with described charging enable signal end, described powered battery judgement signal end, described battery-end BAT, reference power source end REF, and output charging voltage error signal is to described pulse width modulation module.

Described charging current control module is connected with described charging enable signal end, described powered battery judgement signal end, described reference power source end REF, receive the current signal ISENSE of the power inductance feedback of described switch power level, output battery charging current error signal is to described pulse width modulation module.

Described pulse width control module is connected with described charging enable signal end, described powered battery judgement signal end, the output pulse width modulation signal is used for described charging voltage error signal is converted to pulse width modulating signal to described switched charge control logic module.

Described switch power level is connected with described switched charge control logic, described battery-end BAT, described system power supply end SYS, comprises high-side power switch pipe, low-side power switch pipe and power inductance.

Described battery-end BAT is connected with an end ground connection of the first capacitor C 1, the first capacitor C 1.

Described switched charge control logic module is connected with described charging enable signal end, described powered battery judgement signal end, described switch power level, described pulse width modulation module, reception is by the pulse width modulating signal of described pulse width modulation module output, and controls the conducting pulsewidth of described high-side power switch pipe and described low-side power switch pipe according to described pulse width modulating signal.

Referring to Fig. 2, as a kind of embodiment, described charging voltage control module comprises the first differential amplifier, the first resistance R 1 and the second resistance R 2.

One end of the first resistance R 1 is connected with described battery-end BAT, and the other end is connected with an end of the second resistance R 2, and the tie point of the first resistance R 1 and the second resistance R 2 is as the anode input CHFB of the first differential amplifier, the other end ground connection of the second resistance R 2.

The negative input end of the first differential amplifier connects reference power source end REF, and output output charging voltage error signal is to the pulse width modulation module.

Described charging enable signal CHGEN and described powered battery judgement signal USEBAT are connected to two Enable Pins of described the first differential amplifier.

Such connected mode makes cell voltage VBAT obtain anode input voltage CHFB through the first resistance R 1 and the second resistance R 2 dividing potential drops, and negative input end connects reference voltage V _REFThereby, to cell voltage VBAT and the reference voltage V through dividing potential drop _REFCarry out differential amplification.In case find that VBAT surpasses V _REF, the charging voltage error signal can rise; If VBAT is less than V _REF, the charging voltage error signal can descend.

Referring to Fig. 3, as a kind of embodiment, described charging current control module comprises the second differential amplifier.

The positive input terminal access of described the second differential amplifier is by the current signal ISENSE of the power inductance feedback of described switch power level, negative input end is connected with described reference power source end REF, and output output battery charging current error signal is to described pulse width modulation module.

Described charging enable signal CHGEN and described powered battery judgement signal USEBAT are connected to two Enable Pins of described the second differential amplifier.

In case find that ISENSE surpasses V _REF, the battery charging current error signal can rise; If ISENSE is less than V _REF, the battery charging current error signal can descend.

Referring to Fig. 4, as a kind of embodiment, described pulse width modulation module comprises the 3rd differential amplifier, the first comparator, superpositing unit, the second capacitor C 2, the 3rd capacitor C 3, the 4th capacitor C 4, the 3rd resistance R 3, the 4th resistance R 4 and the 5th resistance R 5.

Described superpositing unit is with described charging voltage error signal, the stack of described battery charging current error signal.

One end of described the 3rd resistance R 3 is connected with the output of described superpositing unit, and the other end of described the 3rd resistance R 3 is connected with the negative input end of described the 3rd differential amplifier, and the positive input terminal of described the 3rd differential amplifier is connected with described reference power source end REF.One end of described the second capacitor C 2 is connected with the output of described superpositing unit, and the other end of described the second capacitor C 2 is connected with an end of described the 4th resistance R 4, and the other end of described the 4th resistance R 4 is connected with the negative input end of described the 3rd differential amplifier.

One end of described the 5th resistance R 5 is connected with the negative input end of described the 3rd differential amplifier, the other end of described the 5th resistance R 5 is connected with an end of described the 3rd capacitor C 3, and the other end of described the 3rd capacitor C 3 is connected with the output of described the 3rd differential amplifier.One end of described the 4th capacitor C 4 is connected with the negative input end of described the 3rd differential amplifier, and the other end is connected with the output of described the 3rd differential amplifier.

The output of described the 3rd differential amplifier is connected with the negative input end of described the first comparator, the positive input terminal input triangular wave of described the first comparator.The output output pulse width modulation signal of described the first comparator.

Charging voltage error signal, battery charging current error signal are applied, then be input to the compensation that is formed by the 3rd differential amplifier and resistance capacitance and amplify network, the output error signal VEA of resonant earthed system is connected to the first comparator negative input end, the first comparator positive input terminal connects triangular wave, the output output pulse width modulation signal of the first comparator.

Described charging enable signal CHGEN and described powered battery judgement signal USEBAT are connected to two Enable Pins (not shown in Fig. 4) of described the 3rd differential amplifier.

In case in battery charging current error signal, charging voltage error signal, any one rises over V _REF, the error signal VEA of the output of the 3rd differential amplifier will be descended, equal the ratio of VEA and triangular wave amplitude VSAW due to the pulse-width signal duty ratio, namely

Thereby cause the duty ratio of pulse-width signal to descend, make the switched charge electric current descend.

As a kind of embodiment, the high-side power switch Guan Weiyi P channel MOS tube of described switch power level, described low-side power switch Guan Weiyi N-channel MOS pipe.

The grid of described P channel MOS tube be connected the grid of N-channel MOS pipe and be connected with described switched charge control logic.

The source electrode of described P channel MOS tube is connected with described system power supply end SYS, and the drain electrode of described P channel MOS tube is connected with the drain electrode of described N-channel MOS pipe, the source ground of described N-channel MOS pipe.Described P channel MOS tube be connected the tie point of N-channel MOS pipe and be connected with an end of described power inductance.

The other end of described power inductance is equipped with current detection circuit, in order to the flow through electric current of power inductance and the current signal ISENSE that detects is passed to described charging current control module of detection.

Described switched charge module is controlled charging current and charging target voltage by the duty ratio of the conducting of the described high-side power switch pipe of adjusting and low-side power switch pipe.In the power source loads ability during less than system power supply end SYS loading demand, the conducting of high-end P channel MOS tube, low side N-channel MOS pipe is closed, and battery can be powered to system power supply by the power source path that inductance and high-end P channel MOS tube form.

Referring to Fig. 5, as a kind of embodiment, described switched charge control logic module comprises power tube control logic unit, controlled timer and the second comparator or digital to analog converter (ADC).Switched charge control logic received pulse bandwidth modulation signals, charging enable signal CHGEN, powered battery judgement signal USEBAT and clock frequency, the turn-on and turn-off of control high-side power switch pipe and low-side power switch pipe.Described switched charge control module also is provided with the self adaptation chronograph mechanism, mainly coordinated with current detection circuit by controlled timer and complete, the actual charge current size that controlled timer detects according to current detection circuit, change the timing length of timer, perhaps change the frequency of timer clock signal, thereby effectively avoid actual charge current to cause the overtime problem of charging less than setting charging current.

Described the second comparator or digital to analog converter are connected with described reference power source end REF, described charging Enable Pin be connected current detection circuit and connect, output current data signal or electric current comparison signal are to described controlled timer.

Described controlled timer is connected with described charging enable signal end, and receive clock frequency signal and current data signal or electric current comparison signal, export the charging timeout signal to described power tube control logic unit simultaneously.

Referring to Fig. 6, as a kind of embodiment, described controlled timer comprises two above frequency dividers and multiselect one MUX and timer.

The input of described a plurality of frequency dividers all receives described clock frequency signal, and the output of described frequency divider is connected with described multiselect one MUX, and the crossover frequency of described plural frequency divider is for making the ascending series of equal difference with the inverse of frequency divider number.N frequency divider even arranged, and the divide ratio of the first frequency divider is 1/n, and the divide ratio of the second frequency divider is 2/n, and the divide ratio of tri-frequency divider is 3/n ... until (n-1)/n frequency division, 1 frequency division.

Multiselect one MUX also receives described current data signal ISENSE or described electric current comparison signal, and output timer clock frequency is to described timer.

Described timer also is connected with described charging Enable Pin.

The course of work of described controlled timer is that the frequency divider of a plurality of different divide ratios is originated clock and converted the clock signal of different frequency to, outputs to multiselect one MUX MUX.Digital to analog converter ADC converts the charging current that detects to digital signal both charging current data, outputs to multiselect one MUX, selects the frequency of corresponding charging current, and output timer clock frequency is to counter.If charging current diminishes, the charging current data that ADC sends diminish thereupon, and charging current Data Control multiselect one MUX is selected lower timer frequency output.Therefore, the timer clock frequency changes along with the variation of charging current.The slack-off time span that is equivalent to extend timer of timer clock frequency.Timer is accepted the timer clock frequency, in case charging enable signal CHGEN=1, timer begins timing.Thereby realized that timer changes and the function of dynamic change with size of current.

Described power tube logic control element receives charging enable signal CHGEN, powered battery judgement signal USEBAT and described pulse width modulating signal and charging timeout signal, output high-side power switch pipe controls signal to described high-side power switch pipe, and output low-side power switch pipe controls signal to described low-side power switch pipe.

Referring to Fig. 7, as a kind of embodiment, described power tube logic control element is by trigger D1, first with a door AN1, second with door AN2, the 3rd with AN3, first or the door OR1, second or the door OR2, the first inverter I1, the second inverter I2, the 3rd inverter I3, the 4th inverter I4, the first driving stage B1, the second driving stage B2 form.

after described powered battery judgement signal USEBAT is anti-phase through the 4th inverter I4 with described charging enable signal CHGEN and described charging timeout signal as described first with three input end signals of door AN1, first with output end signal and the described clock frequency signal of door AN1 as described second with two input end signals of an AN2, described first with the door AN1 output end signal anti-phase through the first inverter I1 after with described pulse width modulating signal as described first or the door OR1 two input end signals, described second is connected to the S end of described trigger D1 with the output end signal of door AN2, described first or the output end signal of door OR1 be connected to the R end of described trigger D1.

The Q end signal of described trigger D1 after the 3rd inverter I3 is anti-phase with the output end signal of described the second driving stage B2 as described second or two input end signals of door OR2, described second or the output end signal of door OR2 be connected to the input of described the first driving stage B1, the output end signal of described the first driving stage B1 is described high-side power switch management and control signal processed, is connected to described high-side power switch pipe.

The Q end signal of described trigger after the second inverter I2 is anti-phase with described first with the output end signal of the door output end signal of AN1 and the first driving stage B1 as the described the 3rd with three input end signals of door AN3, the described the 3rd is connected to the input of described the second driving stage B2 with the output end signal of door AN3, the output end signal of described the second driving stage B2 is described low-side power switch management and control signal processed, is connected to described low-side power switch pipe.

As a kind of embodiment, the D1 of trigger described in the present embodiment is d type flip flop, and those skilled in the art can select according to actual conditions the trigger of other types.

The course of work of described power tube logic control element is: when charging enable signal CHGEN is 0 or powered battery judgement signal USEBAT when being 1, first with the output EN of door AN1 be zero.Trigger D1 is output as zero, and high-side power switch management and control signal processed is 1, and high-side power switch pipe (PMOS pipe) keeps turn-offing; Simultaneously, low-side power switch management and control signal processed is 0, and low-side power switch pipe (NMOS pipe) keeps turn-offing.When charging enable signal CHGEN is that when 1 while, powered battery judged that signal USEBAT was zero, EN is 1.Clock signal pulse puts 1 with trigger D1, and high-side power switch management and control signal processed is 0, the conducting of high-side power switch pipe, and the signal processed of low-side power switch management and control simultaneously is 0, the low-side power switch pipe keeps turn-offing; In case pulse width modulating signal is 1, first or a door OR1 be output as 1, trigger D1 is output as zero, high-side power switch management and control signal processed is 1, the shutoff of high-side power switch pipe, low-side power switch management and control signal processed is 1, the conducting of low-side power switch pipe.

Wherein second or a door OR2 effect be, low-side power switch management and control signal processed is 1 o'clock, keeping high-side power switch management and control signal processed is 1, keep the high-side power switch pipe to turn-off, prevent the conducting simultaneously of high-side power switch pipe and low-side power switch pipe, cause system power supply end VSYS to produce the large electric current on ground by high-side power switch pipe and low-side power switch pipe.Wherein the 3rd with the door AN3 effect be, high-side power switch management and control signal processed is 0 o'clock, keeping low-side power switch management and control signal processed is 0, keep the low-side power switch pipe to turn-off, prevent the conducting simultaneously of high-side power switch pipe and low-side power switch pipe, cause system power supply end VSYS to produce the large electric current on ground by high-side power switch pipe and low-side power switch pipe.

in the prior art, in order to guarantee lithium cell charging safety, lithium battery charger generally all can be set a charging safety timer, in case the charging interval arrives the timer setting-up time, and charging process not yet finishes, charger will stop charging, and output charging abnormal end signal, to prevent the fortuitous event appearance of charging, but because the input power driving force often might arrange electric current less than charging, even the input power driving force is enough, also may be due to system's power consumption and charging current sum greater than the input power driving force, cause actual charge current less than normal, charging interval is elongated, the setting-up time that even exceeds timer, cause charger to stop charging, and the wrong charging abnormal end signal that sends.

The digital to analog converter ADC of switched charge module of the present invention is converted into digital signal with the charging current that detects, perhaps by the second comparator, the charging current that detects and the current value of setting are compared, automatically change the length of timer, perhaps change the counter clock frequency, the length of the overtime timer of charging of lithium battery is changed with charging current, work as I _CHGWhen being reduced near zero current, timer can keep stopping timing.

Preferably; described switched charge module also comprises battery overheat protector module and chip overheat protector module; when chip temperature or battery temperature exceed the safe working temperature scope; to automatically reduce charging current or automatically stop charging, until chip temperature or battery temperature are returned in the safe working temperature scope.

The overtime timer length of the charging of traditional lithium battery charger is fixed, and can not adjust along with the size of charging current the clock frequency of timing length and timing.Due to external power source ability I _DRIVEFix, along with the power consumption I of system _SYSVariation, I _DRIVEAnd I _SYS+ I _CHGRelative size when changing, I _CHGCan be along with I _SYSChange and change, work as I _DRIVE＜I _SYSThe time, charging current even can be reduced to zero.Therefore can there be wrong overtime danger in traditional timer.Therefore the controlled timer with charging current change timing length in the present invention, effectively avoided elongating because system's power consumption causes the charging interval the overtime problem of timer mistake of bringing.

A kind of switched charge circuit provided by the present invention, do not need software programming, realize by hardware fully, effectively solve the problem of the enforcement complexity that exists in prior art, solved simultaneously and adopted the linear-charging mode to carry out large current charge and the problem such as the chip heating, the timer mistake that cause be overtime.

Embodiment two

Referring to Fig. 8, as a kind of embodiment, described power-supply management system comprises that the first voltage comparison module, second voltage comparison module, Logic control module, the first voltage keeps module, second voltage and keep module, the first switch element, second switch unit, reference power source end REF, external power source input ACIN, system power supply end SYS, battery-end BAT, also comprises switched charge module and the first voltage transformation module.

Described reference power source end REF produces reference voltage, as described power-supply management system conversion and reference voltage relatively.

Described the first switch element is kept module, the first voltage transformation module and system power supply end SYS with external power source input ACIN, the first voltage and is connected.Comprise the first switching tube, described the first switching tube is a PMOS pipe or PNP pipe.

Described the first voltage comparison module and described external power source input ACIN be connected reference power source end REF and be connected, external power source input terminal voltage V relatively _ACINWith battery terminal voltage V _BAT, output external power source useful signal ACINVALID is to described Logic control module.

Described second voltage comparison module and described system power supply end SYS be connected battery-end BAT and be connected, comparison system terminal voltage V _SYSWith battery terminal voltage V _BAT, output powered battery judgement signal USEBAT is to described Logic control module.

Described Logic control module is connected in described the first voltage comparison module and second voltage comparison module, reception external power source useful signal ACINVALID and powered battery judgement signal USEBAT, and output charging enable signal CHGEN, powered battery selection signal SELBAT and external power source selection signal SELACIN.

Referring to Fig. 9, as a kind of embodiment, described the first voltage is kept module, is connected in reference power source end REF, external power source input ACIN, export the first voltage and keep signal to the first switch element, comprise the 6th resistance R 6, the 7th resistance R 7 and the 4th differential amplifier.The positive input terminal of the 4th differential amplifier is connected to reference power source.

After the dividing potential drop of external power source input voltage ACIN through the 6th resistance R 6 and the 7th resistance R 7, the dividing potential drop ACDIV that obtains is connected to the differential amplifier negative input end.Because

So magnitude of voltage of keeping that dividing potential drop ratio and reference power source by the 6th resistance R 6 and the 7th resistance R 7 can arrange external power source input voltage ACIN.Differential amplifier output VO output the first voltage keep signal both the first voltage keep the output signal of module.

The first voltage is kept the base stage that signal is connected to grid or a PNP pipe of a PMOS pipe.As external power source input voltage V _ACINDescend, cause ACDIV less than V _REF, make the first voltage keep signal and rise, due to the grid voltage rising of a PMOS pipe, the resistance of a PMOS pipe is increased, the electric current that flows through a PMOS pipe is reduced, thereby keep ACIN voltage in set point.

Referring to Figure 10, as a kind of embodiment, described the first voltage transformation module is connected in external power source input ACIN, reference power source end REF, system power supply end SYS, and output the first voltage transitions controls signal to described the first switch element.The first voltage transformation module comprises that the 8th resistance R 8, the 9th resistance R 9 and the 5th differential amplifier form.The negative input end of the 5th differential amplifier is connected to reference power source.

After the dividing potential drop of system power supply voltage VSYS through the 8th resistance R 8 and the 9th resistance R 9, the dividing potential drop FB that obtains is connected to the differential amplifier negative input end.Because

So ratio and reference power source by the 8th resistance R 8 and the 9th resistance R 9 dividing potential drops can arrange VSYS voltage.The 5th differential amplifier output VO output the first voltage transitions signal is the output signal of the first voltage transformation module both.

The first voltage transitions signal is connected to the base stage of grid or a PNP pipe of a PMOS pipe.When system power supply end SYS voltage VSYS descends, cause FB less than VREF, the voltage transitions control signal is descended, therefore the grid voltage decline due to a PMOS pipe reduce the resistance of a PMOS pipe; When system power supply end SYS voltage VSYS rises, cause FB higher than VREF, make the first voltage transitions signal increase, due to the grid voltage rising of a PMOS pipe, the resistance of a PMOS pipe is increased.The 5th differential amplifier makes system power supply end SYS voltage VSYS reach dynamic equilibrium, makes FB equal VREF, thereby keeps VSYS voltage in set point.

Described second switch unit is connected with battery-end BAT, Logic control module and system power supply end SYS, comprises the second switch pipe, and described second switch pipe is the 2nd PMOS pipe or the 2nd PNP pipe.

When there is no external power source when input, the second switch cell conduction is system power supply end SYS power supply, and when the external power source input was arranged, the second switch unit was closed.In case find that external power source is not enough to the support system power consumption, the powered battery path will conducting, and external power source be that system power supply end SYS powers together.

Described second voltage is kept module and is connected in system power supply end SYS and reference power source end REF, and the output second voltage is kept signal to the switched charge module.

Described switched charge module comprises switched charge control logic module, charging voltage control module, charging current control module, pulse width control module and switch power level, be connected with described system power supply end SYS, described reference power source end REF, described battery-end BAT, receive by the charging enable signal CHGEN of described Logic control module output with by the powered battery judgement signal USEBAT of described second voltage comparison module output and by the second voltage that described second voltage is kept module output and keep signal.

The internal structure of the switched charge module of the present embodiment is similar to embodiment one, repeats no more.Referring to Figure 10, wherein, what the present embodiment was different from embodiment one is, described second voltage is kept the superpositing unit that signal exports the pulse width modulation module of described switched charge module to, namely as a kind of embodiment, described charging voltage error signal, described battery charging current error signal and described second voltage are kept signal and are superposeed by described superimposer in the lump.

The specific works process of the power-supply management system that the present embodiment provides is: the first voltage comparison module is V relatively _ACINAnd V _BATHeight, work as V _ACINHigher than V _BATDuring certain value, output external power source useful signal ACINVALID is to Logic control module.When having external power source input and battery-end BAT to connect battery, because general outside input power will possess the ability that charges the battery, must satisfy outside input supply voltage higher than battery-end BAT voltage.As input power terminal voltage signal V _ACINWith battery-end BAT voltage signal V _BATSatisfy and concern V _ACIN〉=V _BAT+ Δ V1, wherein Δ V1 represents the difference of a d. c. voltage signal, the difference of d. c. voltage signal is not done special restriction herein, only represents that there are a difference in input power terminal voltage signal and battery-end BAT voltage signal, the difference of d. c. voltage signal can value 0.2V for example.Work as V _ACIN〉=V _BATWhen+Δ V1 relation satisfies, the first voltage comparison module output signal ACINVALID=1, otherwise output signal ACINVALID=0.

The second voltage comparison module is V relatively _BATAnd V _SYSThe height of voltage, output powered battery signal (USEBAT) is to Logic control module.As battery-end BAT voltage signal V _BATWith system power supply end SYS voltage signal V _SYSSatisfy and concern V _BAT〉=V _SYS+ Δ V2, wherein Δ V2 represents the difference of a d. c. voltage signal, the difference of d. c. voltage signal is not done special restriction herein, only represents that there are a difference in battery-end BAT voltage signal and system power supply end SYS voltage signal, the difference of d. c. voltage signal can value 0.04V for example.Work as V _BAT〉=V _SYSWhen+Δ V2 relation satisfies, second voltage comparison module output signal U SEBAT=1, otherwise output signal U SEBAT=0.

Work as V _BAT〉=V _SYSDuring+Δ V2, show the external power source scarce capacity so that system's power consumption to be provided, need the conducting of battery auxiliary power supply path.At this moment, switched charge module reception battery auxiliary power supply signal makes the high-end MOS conducting in the switched charge module, and the low side metal-oxide-semiconductor is closed, the closing switch charge function, make simultaneously high-end MOS and inductance form the auxiliary power supply path, this path will be powered from battery to system power supply end SYS.

Logic control module receives powered battery judgement signal USEBAT and external power source useful signal ACINVALID, and the output external power source selects signal SELACIN, powered battery to select signal SELBAT and charging enable signal CHGEN.Different with powered battery judgement signal USEBAT state according to the external power source useful signal ACINVALID that receives, be divided into three kinds of situations: (1) when ACINVALID=0, no matter USEBAT state why, exporting is all SELBAT=1, CHGEN=0; (2) work as ACINVALID=1, during USEBAT=0, be output as SELBAT=0, CHGEN=1; (3) work as ACINVALID=1, during USEBAT=1, be output as SELBAT=1, CHGEN=0.

Described the first switch element is a PMOS pipe or PNP pipe.The first voltage is kept module and is received external power source and select signal SELACIN, when external power source when to select signal SELACIN be high, to outside power input voltage V _ACINAnd V _REFDifference amplify, output the first voltage is kept the base stage of grid or a PNP pipe of signal to a PMOS pipe, changes the resistance of PMOS or PNP pipe, with V _ACINMaintain setting voltage.As the V that receives _ACINDuring decline, cause that the first voltage keeps signal and rise, the PMOS grid voltage rises, make the electric conduction resistive of PMOS pipe large, PMOS pipe conducting resistance rises and makes the electric current that flows through the drain electrode of PMOS pipe descend, and namely descends from the electric current that ACIN flows to VSYS by the PMOS pipe, thereby hinders V _ACINVoltage signal descends.When voltage signal drops to and reference voltage signal V _REFWhen equating, the closed feedback loop that input voltage signal is kept signal and PMOS formation reaches dynamic equilibrium, thereby keeps V _ACINIn set point.

The first power transfer module receives external power source and selects signal SELACIN, when external power source when to select signal SELACIN be high, with V _SYSAnd V _REFDifference amplify, the output voltage changeover control signal is regulated the resistance of PMOS or PNP, with V to the first gate pmos utmost point and PNP pipe base stage _SYSMaintain set point and guarantee system power supply.When receiving V _SYSDecline the time, cause that the voltage transitions control signal descends, the resistance of a PMOS pipe is descended, increase drain current, thereby hinder V _SYSVoltage drop.

In like manner, second voltage is kept module with V _SYSAnd V _REFDifference amplify, the output second voltage is kept signal to the switched charge module, works as V _SYSDrop to the trouble free service voltage V of the required setting of assurance system safety work of setting _{SYS SAFE}After, second voltage is kept signal and will be descended.

After the second voltage that the pulse width modulation module of switched charge module receives decline is kept signal, the duty ratio of charging is reduced, reduce charging current, thereby keep V _SYSTo the trouble free service voltage V that sets _{SYS SAFE}, guarantee the normal operation of system.

Described switched charge module is controlled by charging signals CHGEN, through processes such as trickle charge, constant current charge, constant voltage charges, battery is full of, and then stops charging, and waiting system satisfies the condition of charging again.When the charging enable signal CHGENCHGEN=0 that receives, charge control module charge closing process; As the charging enable signal CHGENCHGEN=1 that receives, charge control module begins charging process.

The power-supply management system that the present embodiment provides when the external power source input is arranged, is started working, if the current driving ability I of outside input power _DRIVELess than the system consumption electric current I _SYSCharging current I with battery _CHGSum, that is: I _DRIVE＜I _SYS+ I _CHG, can cause system power supply end SYS voltage V _SYSDescend.Above-mentioned power-supply management system will be according to different applicable cases autobalance charging and discharging electric currents, the normal operation of assurance system, and its detailed process is described below.

If battery-end BAT voltage V _BATGreater than system safety operating voltage V _{SYS SAFE}, along with V _SYSDecline, V _SYSCan first drop near V _BAT, because there is conducting resistance in the high-side power switch pipe of switched charge module, so the charged electrical that flows to battery-end BAT through the high-side power switch pipe fails to be convened for lack of a quorum along with system power supply end SYS voltage V _SYSDecline and automatically reduce, work as V _SYSDrop to and equal V _BAT, charging current signal ISENSE is reduced to zero.If still there is I this moment _DRIVE＜I _SYS+ I _CHG, V _SYSAlso can continue to drop to and compare V _BATAlso low.

Second voltage comparison module this moment output signal U SEBAT=1; Logic control module is according to ACINVALID=1, and USEBAT=1 output signal CHGEN=0, SELBAT=1, Logic control module will make second switch unit (the 2nd PMOS pipe) conducting at this moment, make battery to system power supply end SYS supplementary power.The signal that the Simultaneous Switching charge control module receives is CHGEN=0 and charge closing process, simultaneously with the high-side power switch pipe conducting of switched charge power stage, and turn-off the low-side power switch pipe, thereby the auxiliary power supply path conducting that switch power level and power inductance are formed.

This moment the 2nd, PMOS pipe and the conducting simultaneously of switched charge auxiliary power supply path, formed battery together to the path of system power supply, reduces like this resistance of supply access, improves the efficient of system power supply conversion.So this moment input power terminal voltage V _ACINWith battery-end BAT voltage V _BATSupply path conducting simultaneously is to system power supply end SYS voltage V _SYSCooperated power supply has guaranteed that the system power supply end SYS undertension that system can not cause because outside input power current driving ability is not enough makes system's cisco unity malfunction.

If battery-end BAT voltage signal V _BATLess than system safety operating voltage V _{SYS SAFE}, along with system power supply end SYS voltage signal V _SYSDecline, V _SYSCan first drop near V _{SYS SAFE}This moment, second voltage was kept modular system to the difference amplification of power end voltage and reference power source end REF voltage, the output second voltage is kept signal to the switched charge module, after the second voltage that the switched charge module receives decline is kept signal, reduce the conducting pulsewidth of switched charge, reduce charging current.

Work as V _SYSDrop to V _{SYS SAFE}, charging current is reduced to zero, if this moment I _DRIVE＜I _SYS+ I _CHGStill satisfy, V _SYSAlso can continue to descend, until than battery-end BAT voltage signal V _BATAlso low.Second voltage comparison module this moment output signal U SEBAT=1; Logic control module is according to ACINVALID=1, USEBAT=1 output signal CHGEN=0, and SELBAT=1 makes the 2nd PMOS pipe conducting simultaneously.And after the switched charge module receives CHGEN=0, with the charge closing process, make high-side power switch pipe normal open, and turn-off the low-side power switch pipe, make the auxiliary power supply path conducting between system power supply end SYSSYS and battery-end BATBAT.This moment system power supply end SYS voltage signal V _SYSThe source be input power terminal voltage signal V _ACIN, be again battery-end BAT voltage signal V _BAT

The power-supply management system that the present invention proposes can be according to system's power consumption and external power source ability, and the stable operation of system safety is satisfied in dynamic management charging current and system power supply path.Wherein, external power source priority when having external power source to insert, is preferentially used external power source higher than powered battery priority; System power supply priority is higher than the battery priority of charging, the supply current of external power source preferentially satisfies system's need for electricity, the residue power supply capacity is used for the battery charging, when system's power consumption curent change, dynamically adjusts the size of charging current according to system's power consumption and external power source ability; When external power source was not enough to the support system power consumption, starting the powered battery path was system power supply, and this moment, the external power source insufficient section was provided by battery.

the power-supply management system of the present embodiment has in the situation of a plurality of inputs sources at the same time, preferentially use external power source to be system power supply, under the prerequisite of preferential assurance system power supply, the remaining external power source electric current that satisfies after system's electricity consumption is used for charging the battery, according to external power source load capacity and system's electricity consumption situation dynamic assignment charging current, can prevent outside input power is not enough to simultaneously to system power supply and when charging the battery, and the problem that the system that causes can't work, solved also simultaneously that the timer mistake is overtime and the linear-charging electric current is little, inefficient problem.

Embodiment three

Shown in Figure 12, as a kind of embodiment, power-supply management system of the present invention comprises that the first voltage comparison module, second voltage comparison module, Logic control module, the first voltage keeps module, second voltage and keep module, the first switch element, second switch unit, reference power source end REF, external power source input ACIN, system power supply end SYS, battery-end BAT, switched charge module and the first voltage transformation module, also comprises linear-charging module, the first current limliting module and the second current limliting module.

Described linear-charging module and described battery-end BAT, described reference power source end REF be connected the second switch unit and be connected.

The linear-charging module is connected in the second switch unit, controls charging current and charging voltage.In this power-supply management system, linear-charging module and switched charge module cooperating.At first charging circuit is enabled the switched charge circuit, and monitoring current size simultaneously is when battery approaches when being full of, charging current will reduce, when charging current during less than preset value, closing switch charging circuit at first, then starting the linear-charging circuit is the battery charging.

During the work of linear-charging module, system power supply voltage is not disturbed, but efficient is lower, the electric energy loss in chip is very high, and these electric energy losses will convert heat to, cause when large current charge, makes the chip heating serious.Switched charge module charge efficiency is high, and the electric energy loss in chip is little, but owing to frequently changing switch, can cause interference to system power supply voltage.Therefore the technical solution used in the present invention is for charging current being detected when very little, system opens the linear-charging module and charges the battery, the automatic cut-off switch charging module because charging current is little, therefore the chip heating is little, has also avoided the interference of switched charge to system power supply voltage simultaneously; When the charged electrical rheology being detected when large, autoshutdown linear-charging module is opened the switched charge module and is charged the battery, and utilizes the ability of switched charge high efficiency and large current charge, can avoid the chip heating, makes simultaneously battery be full of fast electricity.

Referring to Figure 13, as a kind of embodiment, described the first current limliting module receives the current signal ISENSE that external power source is selected signal SELACIN and fed back by described external power source input ACIN, and output the first current limliting signal is to described the first switch element.The first current limliting module comprises the 6th differential amplifier.

In the present embodiment, externally power input ACIN is provided with current detection circuit, described current detection circuit is connected to the current signal ISENSE that detects the positive input terminal of the 6th differential amplifier, the negative input end of the 6th differential amplifier connects reference power source end REF, the output VO output first Current limited Control signal of the 6th differential amplifier.The first Current limited Control signal is passed to the base stage of grid or a PNP pipe of a described PMOS pipe.To after current signal ISENSE being detected and surpassing reference power source terminal voltage VREF, the first Current limited Control signal rises, and the resistance of a PMOS pipe or a PNP pipe is increased, and the electric current of the collector electrode that flows through a PMOS pipe drain electrode or a PNP pipe is reduced.

Described the second current limliting module and described battery-end BAT are connected with the second switch unit, receive the current signal ISENSE by described battery-end BAT feedback.Comprise the 7th differential amplifier.Described battery-end BAT also is provided with a current detection circuit, described current detection circuit is passed to the current signal ISENSE that detects the positive input terminal of the 7th differential amplifier, the negative input end of the 7th differential amplifier is connected with described reference power source end REF, the grid of output VO output the second current limliting signal to the two PMOS pipes or the base stage of the 2nd PNP pipe.

Referring to Figure 14 and Figure 15, as a kind of embodiment, first switch element of the present embodiment comprises on the first switching tube and first and draws priviledge module, and described the first switching tube is a PMOS pipe or PNP pipe.The output signal that the first voltage is kept module, the first voltage transformation module and the first current limliting module adopts draws after preferential mode superposes, and is connected to the base stage of a PMOS grid or a PNP pipe.External power source input voltage ACIN drops to ACIN and keeps that voltage, VSYS surpass set point and PMOS pipe drain current surpasses any appearance in these three kinds of situations of set point, the capital causes the grid voltage of a PMOS pipe to be drawn high, increase the resistance of a PMOS pipe, prevent that these three kinds of fortuitous events from occuring.

Referring to Figure 15, as a kind of embodiment, the current source that draws on described first priviledge module to comprise that the 3rd PMOS pipe, the 4th PMOS pipe, the 5th PMOS pipe and current direction point to ground (direction as shown is for downwards) forms.A, B, C are three inputs that draw priviledge module on described, and VO is output.When A point signal descended, the resistance of the PMOS pipe of A point connection descended, in case when this PMOS tube resistor pull-up current ability surpasses the electric current of current source, will make VO increase.Therefore A, B, any one signal of C descend, and when causing the pull-up current of corresponding PMOS pipe to surpass the electric current of downward current source, all will cause VO to rise.

As a kind of embodiment, described second switch unit comprises on second switch pipe and second and draws priviledge module, described second switch pipe is the 2nd PMOS pipe or the 2nd PNP pipe, draw the structure of priviledge module to draw priviledge module on described second on first, draw the number setting of the PMOS pipe of priviledge module to depend on the number of input signal on second, those skilled in the art can change flexibly according to the application's technical conceive, are not further qualified herein.

Native system is by arranging the first current limliting module for external power source ACIN supply path provides current-limiting function, the second current limliting module is set simultaneously provides current-limiting function for the supply path of battery-end BAT.When the electric current that flows through supply path being detected and surpassed the current limliting set point, the first current limliting module or the second current limliting module are with I _SenseAmplify with the difference of reference signal, the output current limiting control signal increases the resistance of big pmos to the grid of supply path PMOS pipe, makes electric current be limited in the security settings electric current.Resistance increase due to supply path PMOS will cause V _SYSDescend, work as V _SYSDrop to system closedown voltage V _{SYS OFF}After, system will close supply path, until after short circuit condition was cancelled, supply path can be opened, thereby burns when effectively preventing chip by short circuit.Owing to the wrong usage that output is shorted to ground often occurring in application, therefore all to have current-limiting function be the effective and indispensable safety measure of system when wrong short circuit to two supply paths, can prevent that locking system electric current when short circuit can be limited in safe range, the assurance system can not burnt.

Embodiment four

Referring to Figure 16, originate owing to usually having two external power source inputs of adapter input port and USB interface in electronic equipment.Therefore the present embodiment provides the solution that has simultaneously external adapter input port and USB interface.

As a kind of embodiment, power-supply management system provided by the invention comprises that also tertiary voltage comparison module, second voltage modular converter, tertiary voltage keep module, USB current limliting module, VBUS input and the 3rd switch element.

The operation principle of described tertiary voltage comparison module and described the first voltage comparison module is similar, is connected with described VBUS input, described battery-end BAT, and output VBUS useful signal VBUSVALID is to described Logic control module.

It is similar that described tertiary voltage is kept the operation principle that module and described the first voltage keeps module, be connected with described VBUS input, described reference power source end REF, reception is selected signal by the VBUS of described Logic control module output, and the output tertiary voltage is kept signal to described the 3rd switch element.

The operation principle of described second voltage modular converter and described the first voltage transformation module is similar, be connected with system power supply end SYS, reference power source end REF, reception is selected signal by the VBUS of described Logic control module output, and output second voltage switching signal is to described the 3rd switch element.

The operation principle of described the 3rd switch element and the first switch element is similar, comprises the 3rd PMOS pipe, is connected with described VBUS input, system power supply end SYS.

The first voltage comparison module of the power-supply management system of the present embodiment, second voltage comparison module, Logic control module, the first voltage are kept module, second voltage and are kept module, the first switch element, second switch unit, reference power source end REF, external power source input ACIN, system power supply end SYS, battery-end BAT, switched charge module and the first voltage transitions, the annexation of these composition modules and the course of work are not being given unnecessary details with reference to previous embodiment.The below describes the course of work of the relevant module of USB interface in detail.

The tertiary voltage comparison module is with V _VBUSAnd V _BATRelatively, output V _VBUSPower supply useful signal VBUSVALID.The second voltage modular converter is with V _SYSAnd V _REFDifference amplify, the output voltage changeover control signal makes VBUS be transformed into V to the grid of VBUS path P metal-oxide-semiconductor (the 3rd PMOS manages) _SYSWhen USB connects, must guarantee V _VBUSConnect voltage V higher than safety _VBUSHOLDIn case, because system's power consumption causes V _VBUSDrop to V _VBUSHOLDBelow, will cause USB to go offline.Therefore tertiary voltage is kept module and is detected V _VBUS, work as V _VBUSDrop to USB line safe voltage V _VBUSHOLD, will export tertiary voltage and keep module to VBUS path P metal-oxide-semiconductor grid, increase the resistance of big pmos, reduce VBUS to the electric current of SYS end, make V _VBUSMaintain V _VBUSHOLDCan not continue to descend, thereby guarantee that USB can not go offline.

When having simultaneously ACIN input and VBUS input, preferentially use the ACIN power consumption, electricity can not taken out from VBUS by the assurance system, causes VBUS to connect and occurs extremely.If in case find that ACIN is not enough to the back-up system power consumption and causes V _SYSDrop to V _{SYS SAFE}, the VBUS supply access will start, and this moment, ACIN and VBUS be system power supply jointly, and the assurance system works.If I _ACIN+ I _VBUS＜I _SYS, V _SYSWill drop to less than V _BATIn case, V _BAT〉=V _SYS+ Δ V2 condition satisfies, system will make the conducting of powered battery path P metal-oxide-semiconductor, and opens the auxiliary power supply path of switched charge, and this moment, supply current was provided jointly by ACIN, VBUS and BAT tripartite, the normal operation of assurance system can also guarantee the normal connection of USB simultaneously.Therefore, the present invention provides double safeguard protection for the normal connection of USB.

The disclosed technical scheme of present embodiment, in order to guarantee system stability work, can realize simultaneously the safe charging to lithium ion battery, has lithium battery power supply, when the input of two-way external power source is arranged again simultaneously, three kinds of power supplies have been divided used priority and each self-charging, the course of work of three kinds of power supplies have been done rational regulation and control.

In the situation that external power source is arranged, preferentially use external power source to be system power supply, the priority of simultaneity factor power supply is also higher than the priority of charging.Under the preferential prerequisite that guarantees system power supply, the remaining external power source electric current that satisfies after system's electricity consumption is used for charging the battery, so power-supply management system need to be according to external power source load capacity and system's electricity consumption situation dynamic assignment charging current.When the input of AC adapter and USB interface external power source was arranged, AC adapter power supply priority because if the USB power supply is dragged down by load current, can cause the failure of USB line higher than the USB power supply simultaneously.Therefore when having at the same time the input of AC adapter and USB power supply, preferentially from the AC adapter power supply, guarantee that the USB supply voltage is normal, make the USB line can abnormal; When if AC adapter is not enough to the feed system power consumption, can enable the USB power supply, this moment AC adapter and USB power supply simultaneously to system power supply, the normal operation of assurance system; If powering simultaneously, AC adapter and USB also be not enough to satisfy system's power consumption requirements, just start powered battery, this moment, system will be by AC adapter, USB and battery three-way power simultaneously to system power supply, not only can satisfy the power consumption requirements of system works, can also guarantee that the USB supply voltage can because system's power consumption drags down, not guarantee that the USB line is normal.

Power-supply management system provided by the invention, realize the high efficiency safe charging of the large electric current of lithium battery, and automatically select the power supply path according to the situation of electronic device exterior input power and loading condition, and autobalance between charging and power supply, realize the automatic distribution of electric energy, the normal operation of assurance system.The Simultaneous Switching charging module also has and the self-reacting timer of actual charge current, avoids the overtime problem of the actual charge current charging that causes less than normal.

Should be noted that at last obviously, those skilled in the art can carry out various changes and modification and not break away from the spirit and scope of the present invention the present invention.Like this, if within of the present invention these were revised and modification belongs to the scope of claim of the present invention and equivalent technologies thereof, the present invention also was intended to comprise these changes and modification.

Claims (14)

1. switched charge circuit, comprise system power supply end, battery-end, reference power source end, charging enable signal end and powered battery judgement signal end, it is characterized in that, also comprise the switched charge module, described switched charge module comprises switched charge control logic module, charging voltage control module, charging current control module, pulse width control module and switch power level;

Described switched charge control logic module, described charging voltage control module, described pulse width control module all are connected with described charging enable signal end, described powered battery judgement signal end;

Described charging voltage control module also is connected with described battery-end, reference power source end, and output charging voltage error signal is to described pulse width modulation module;

Described pulse width modulation module output pulse width modulation signal is used for described charging voltage error signal is converted to pulse width modulating signal to described switched charge control logic module;

Described switch power level also is connected with described battery-end, described system power supply end, comprise high-side power switch pipe, low-side power switch pipe and power inductance, the conducting pulsewidth of described high-side power switch pipe and described low-side power switch pipe determines the size of charging current;

Described charging current control module is connected with described charging enable signal end, described powered battery judgement signal end, described reference power source end, receive the current signal of the power inductance feedback of described switch power level, output battery charging current error signal is to described pulse width modulation module;

Described switched charge control logic module also is connected with described switch power level, is used for controlling according to described pulse width modulating signal the conducting pulsewidth of described high-side power switch pipe and described low-side power switch pipe, and then regulates charging current.

2. switched charge circuit according to claim 1, is characterized in that, described charging voltage control module comprises the first differential amplifier, the first resistance and the second resistance;

One end of described the first resistance is connected with described battery-end, the other end of described the first resistance be connected an end of the second resistance and connect, the other end ground connection of described the second resistance;

Tie point between described the first resistance and described the second resistance is connected with the positive input terminal of described the first differential amplifier;

The negative input end of described the first differential amplifier is connected with described reference power source end;

The output output charging voltage error signal of described the first differential amplifier.

3. switched charge circuit according to claim 1, is characterized in that, described charging current control module comprises the second differential amplifier;

The positive input terminal access of described the second differential amplifier is by the current signal of the power inductance feedback of described switch power level, the negative input end of described the second differential amplifier is connected with described reference power source, the output output battery charging current error signal of described the second differential amplification.

4. switched charge circuit according to claim 1, it is characterized in that, described pulse width modulation module comprises the 3rd differential amplifier, the first comparator, superpositing unit, the second electric capacity, the 3rd electric capacity, the 4th electric capacity, the 3rd resistance, the 4th resistance and the 5th resistance;

Described superpositing unit is with described charging voltage error signal, the stack of described battery charging current error signal;

One end of described the 3rd resistance is connected with the output of described superpositing unit, and the other end of described the 3rd resistance is connected with the negative input end of described the 3rd differential amplifier, and the positive input terminal of described the 3rd differential amplifier is connected with described reference power source end;

One end of described the second electric capacity is connected with the output of described superpositing unit, and the other end of described the second electric capacity is connected with an end of described the 4th resistance, and the other end of described the 4th resistance is connected with the negative input end of described the 3rd differential amplifier;

One end of described the 5th resistance is connected with the negative input end of described the 3rd differential amplifier, and the other end of described the 5th resistance is connected with an end of described the 3rd electric capacity, and the other end of described the 3rd electric capacity is connected with the output of described the 3rd differential amplifier;

One end of described the 4th electric capacity is connected with the negative input end of described the 3rd differential amplifier, and the other end is connected with the output of described the 3rd differential amplifier;

The output of described the 3rd differential amplifier is connected with the negative input end of described the first comparator, the positive input terminal input triangular wave of described the first comparator;

The output output pulse width modulation signal of described the first comparator.

5. switched charge circuit according to claim 1, is characterized in that, described switched charge control logic module comprises power tube control logic unit, controlled timer and the second comparator or digital to analog converter;

Described the second comparator or digital to analog converter are connected with described reference power source end, described charging Enable Pin be connected the power inductance of switch power level and connect, output current data signal or electric current comparison signal are to described controlled timer;

Described controlled timer is connected with described charging enable signal end, and receive clock frequency signal and current data signal or electric current comparison signal, export the charging timeout signal to described power tube control logic unit simultaneously;

Described power tube logic control element receives charging enable signal, powered battery judgement signal, described pulse width modulating signal and described charging timeout signal, output high-side power switch pipe controls signal to described high-side power switch pipe, and output low-side power switch pipe controls signal to described low-side power switch pipe.

6. switched charge circuit according to claim 5, it is characterized in that, described power tube control logic unit comprise trigger, first and door, second with door, the 3rd with door, first or, second or door, the first inverter, the second inverter, the 3rd inverter, the 4th inverter, the first driving stage, the second driving stage;

after described powered battery judgement signal is anti-phase through the 4th inverter with described charging enable signal and described charging timeout signal as described first with three input end signals of door, first with output end signal and the clock frequency signal of door as described second with two input end signals, described first with the door output end signal anti-phase through the first inverter after with described pulse width modulating signal as described first or the door two input end signals, described second is connected to the S end of described trigger with the output end signal of door, described first or the output end signal of door be connected to the R end of described trigger,

The Q end signal of described trigger after the 3rd inverter is anti-phase with the output end signal of described the second driving stage as described second or two input end signals of door, described second or the output end signal of door be connected to the input of described the first driving stage, the output end signal of described the first driving stage is described high-side power switch management and control signal processed, is connected to described high-side power switch pipe;

The Q end signal of described trigger after the second inverter is anti-phase with described first with the output end signal of door and the output end signal of the first driving stage as the described the 3rd with three input end signals of door, the described the 3rd is connected to the input of described the second driving stage with the output end signal of door, the output end signal of described the second driving stage is described low-side power switch management and control signal processed, is connected to described low-side power switch pipe.

7. switched charge circuit according to claim 5, is characterized in that, described controlled timer comprises two above frequency dividers and multiselect one MUX and timer;

The input of described plural frequency divider all receives described clock frequency signal, the output of described frequency divider is connected with described multiselect one MUX, and the divide ratio of described plural frequency divider is for making the ascending series of equal difference with the inverse of frequency divider number;

Multiselect one MUX also receives described current data signal or described electric current comparison signal, and output timer clock frequency is to described timer;

Described timer also is connected with described charging Enable Pin.

8. switched charge circuit according to claim 1, is characterized in that, described high-side power switch Guan Weiyi P channel MOS tube, described low-side power switch Guan Weiyi N-channel MOS pipe;

The grid of described P channel MOS tube be connected the grid of N-channel MOS pipe and be connected with described switched charge control logic;

The source electrode of described P channel MOS tube is connected with described system power supply end, and the drain electrode of described P channel MOS tube is connected with the drain electrode of described N-channel MOS pipe, the source ground of described N-channel MOS pipe;

Described P channel MOS tube be connected the tie point of N-channel MOS pipe and be connected with an end of described power inductance, the other end of power inductance is connected with described battery-end.

9. power-supply management system, comprise that the first voltage comparison module, second voltage comparison module, Logic control module, the first voltage keeps module, second voltage and keep module, the first switch element, second switch unit, reference power source end, external power source input, system power supply end, battery-end, it is characterized in that, also comprise switched charge module as claimed in claim 1 and the first voltage transformation module;

Described switched charge module is connected with described system power supply end, described reference power source end, described battery-end, receives by the charging enable signal of described Logic control module output with by the powered battery judgement signal of described second voltage comparison module output and by the second voltage that described second voltage is kept module output and keeps signal;

Described the first voltage transformation module and described system power supply end be connected the reference power source end and be connected, receive by the external power source of described Logic control module output and select signal, output is connected with described the first switch element.

10. power-supply management system according to claim 9, is characterized in that, also comprises the linear-charging module, described linear-charging module and described battery-end, described reference power source end and be connected the second switch unit and be connected.

11. power-supply management system according to claim 9 is characterized in that, also comprises the first current limliting module;

Described the first current limliting module comprises the 6th differential amplifier, the positive input terminal access of described the 6th differential amplifier is by the current signal of described external power source input feedback, negative input end is connected with described reference power source end, and output is connected with described the first switch element.

12. power-supply management system according to claim 9, it is characterized in that, also comprise the second current limliting module, described the second current limliting module comprises the 7th differential amplifier, the positive input terminal access of described the 7th differential amplifier is by the current signal of described battery-end feedback, negative input end is connected with described reference power source end, and output is connected with described second switch unit.

13. power-supply management system according to claim 11 is characterized in that, described the first switch element comprises on the first switching tube and first and draws priviledge module;

Described the first switching tube is a PMOS pipe or PNP pipe;

Draw priviledge module to comprise the 3rd PMOS pipe, the 4th PMOS pipe, the 5th PMOS pipe and a current source that points to ground on described first;

The output that described the first voltage is kept the output of module, described the first voltage transformation module be connected the output of current limliting module and be connected with the grid of described the 3rd PMOS pipe, the grid of the 4th PMOS pipe and the grid of the 5th PMOS pipe respectively;

Be connected to the base stage of grid or a PNP pipe of a described PMOS pipe after the drain electrode short circuit of the drain electrode of the drain electrode of described the 3rd PMOS pipe, the 4th PMOS pipe and the 5th PMOS pipe as output, and be connected the outflow of bus current end ground connection of described current source with the electric current inflow end of described current source.

14. power-supply management system according to claim 9 is characterized in that, comprises that also tertiary voltage comparison module, second voltage modular converter, tertiary voltage keep module, the 3rd switch element, USB current limliting module, VBUS input;

Described tertiary voltage comparison module is connected with described VBUS input, described battery-end, and output VBUS useful signal is to described Logic control module;

Described tertiary voltage is kept module and is connected with described VBUS input, described reference power source end, and the VBUS that receives by described Logic control module output selects signal, and the output tertiary voltage is kept signal to described the 3rd switch element;

Described second voltage modular converter is connected with described system power supply end, reference power source end, and the VBUS that receives by described Logic control module output selects signal, and output second voltage switching signal is to described the 3rd switch element;

The 3rd switch element also is connected with described VBUS input, system power supply end.

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