CN103107562B - 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 technical field of power management, 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 enriches gradually, and electronic product power consumption is increased, needs the power management techniques of portable electric appts constantly progressive and more newly arrive and adapt to product power consumption.

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

In actual applications, the driving force difference of various different input power is very large.Such as, be all the AC adapter of 5V, in order to meet different cost requirements, driving force can 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.Simultaneously along with the issue of handpiece adapter interface national standard, increasing AC adapter also makes USB plug, and therefore applicable cases is more complicated.

Existing charging management chip or power management chip, generally adopt pin to arrange the size of current limliting, needs main control chip to go to detect in real time the situation of external power source access by input/output interface, and resolution is adapter insertion or USB insertion.If adapter input does not just need to arrange current limliting, if find that USB inserts, change current limliting by main control chip Output Interface Control power supply chip pin to arrange, 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 the software and hardware of system all become unusual complexity.Because need main control chip to detect external power source situation in real time, this just needs amendment software, the driver of main control chip.Need to control by output pin the setting that external circuit changes current limliting simultaneously, so just need to increase outside hardware circuit.Therefore need hardware and software engineer coordinated, could realize, and need the plenty of time to verify reliability and the correctness of whole system work; Main control chip needs to detect in real time simultaneously, can take main control chip cpu resource, lower efficiency.

Simultaneously because the capacity of lithium battery constantly becomes large, in order to ensure that the charging interval is in tolerance interval, therefore charging current also constantly increases thereupon.Traditional linear charger, because efficiency is very low, causes chip to generate heat serious, is therefore difficult to the demand meeting 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, which solving of the prior artly needs hardware and software to combine and causes implementing complicated problem, and the problem adopting linear-charging mode to cause chip to generate heat.

For realizing a kind of switched charge circuit 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 and judge signal end, also comprise 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; With described charging enable signal end, described powered battery, described switched charge control logic module, described charging voltage control module, described pulse width control module all judge that signal end is connected; Described charging voltage control module is also connected with described battery-end, reference power source end, exports charging voltage error signal to described Pulse width modulation module; Described Pulse width modulation module output pulse width modulation signal is described switched charge control logic module extremely, for described charging voltage error signal is converted to pulse width modulating signal; Described switch power level is also 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 judges signal end with described charging enable signal end, described powered battery, described reference power source end is connected, receive the current signal of the power inductance feedback of described switch power level, export battery charging current error signal to described Pulse width modulation module; Described switched charge control logic module is also connected with described switch power level, for controlling the conducting pulsewidth of described high-side power switch pipe and described low-side power switch pipe according to described pulse width modulating signal, 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 first resistance is connected with described battery-end, and the other end of described first resistance is connected with one end of described second resistance, the other end ground connection of described second resistance; Tie point between described first resistance and described second resistance is connected with the positive input terminal of described first differential amplifier; The negative input end of described first differential amplifier is connected with described reference power source end; The output of described first differential amplifier exports charging voltage error signal.

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

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 by described charging voltage error signal, described battery charging current error Signal averaging; One end of described 3rd resistance is connected with the output of described superpositing unit, and the other end of described 3rd resistance is connected with the negative input end of described 3rd differential amplifier, and the positive input terminal of described 3rd differential amplifier is connected with described reference power source end; One end of described second electric capacity is connected with the output of described superpositing unit, and the other end of described second electric capacity is connected with one end of described 4th resistance, and the other end of described 4th resistance is connected with the negative input end of described 3rd differential amplifier; One end of described 5th resistance is connected with the negative input end of described 3rd differential amplifier, and the other end of described 5th resistance is connected with one end of described 3rd electric capacity, and the other end of described 3rd electric capacity is connected with the output of described 3rd differential amplifier; One end of described 4th electric capacity is connected with the negative input end of described 3rd differential amplifier, and the other end is connected with the output of described 3rd differential amplifier; The output of described 3rd differential amplifier is connected with the negative input end of described first comparator, the positive input terminal input triangular wave of described first comparator; The output output pulse width modulation signal of described 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 second comparator or digital to analog converter are connected with described reference power source end, the power inductance of described charging Enable Pin and described switch power level connects, and 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 simultaneously receive clock frequency signal and current data signal or electric current comparison signal, export charging timeout signal to described power tube control logic unit; Described power tube logic control element receives charging enable signal, powered battery judges signal, described pulse width modulating signal and described charging timeout signal, export high-side power switch pipe and control signal to described high-side power switch pipe, export low-side power switch pipe and control signal to described low-side power switch pipe.

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

Wherein, described controlled timer comprises two or more frequency divider 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 the ascending series making equal difference with the inverse of frequency divider number; Multiselect one MUX also receives described current data signal or described electric current comparison signal, exports timer clock frequency to described timer; Described timer is also 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 is connected with described switched charge control logic with the grid of described N-channel MOS pipe; 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 is connected with one end of described power inductance with the tie point of described N-channel MOS pipe, and 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 the first voltage comparison module, the second voltage comparison module, Logic control module, the first voltage maintains module, the second voltage maintains module, the first switch element, second switch unit, reference power source end, external power input, system power supply end, battery-end, also comprises 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 the charging enable signal exported by described Logic control module and the second voltage maintenance signal being judged signal by the powered battery of described second voltage comparison module output and exported by described second voltage maintenance module; Described first voltage transformation module is connected with described system power supply end and described reference power source end, and receive the external power source exported by described Logic control module and select signal, output is connected with described first switch element.

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

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

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

Wherein, described first switch element comprises the first switching tube and the first pull-up priviledge module; Described first switching tube is the first PMOS or the first PNP pipe; Described first pull-up priviledge module comprises the current source on the 3rd PMOS, the 4th PMOS, the 5th PMOS and a sensing ground; Described first voltage maintains the output of module, the output of described first voltage transformation module is connected with the grid of the grid of described 3rd PMOS, the grid of the 4th PMOS and the 5th PMOS respectively with the output of the first current limliting module; The grid of described first PMOS or the base stage of the first PNP pipe is connected to as output after the drain electrode short circuit of the drain electrode of described 3rd PMOS, the drain electrode of the 4th PMOS and the 5th PMOS, and flow into hold with the electric current of described current source and be connected, the outflow of bus current end ground connection of described current source.

Wherein, tertiary voltage comparison module, the second voltage transformation module, tertiary voltage maintenance module, the 3rd switch element, USB current limliting module, VBUS input is also comprised; Described tertiary voltage comparison module is connected with described VBUS input, described battery-end, exports VBUS useful signal to described Logic control module; Described tertiary voltage maintains module and is connected with described VBUS input, described reference power source end, receives the VBUS exported by described Logic control module and selects signal, exports tertiary voltage and maintains signal to described 3rd switch element; Described second voltage transformation module is connected with described system power supply end, reference power source end, receives the VBUS exported by described Logic control module and selects signal, export the second voltage conversion signal to described 3rd switch element; 3rd switch element is also 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, the voltage signal of signal and battery-end is judged according to the charging enable signal received and powered battery by arranging charging voltage control module, export charging voltage error signal to described Pulse width modulation module, described Pulse width modulation module is according to charging enable signal, powered battery judges signal and described charging error signal output pulse width modulation signal, described switched charge control logic is again according to the described high-side power switch pipe of pulse width modulating signal adjustment switch power level and the conducting pulsewidth of low-side power switch pipe, and then adjustment charging current, achieve and regulate charging current according to the situation of multiple power supplies input, when large current charge can be carried out to battery-end, increase charging current, solve simple linear-charging and carry out large current charge and the problem causing chip to generate heat, and the employing hardware that the technical scheme of the application is simple, structure understands, implement simple, there will not be due to needs software, combination of hardware and the problem of the enforcement complexity caused.

Accompanying drawing explanation

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 maintains 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;

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

Figure 15 is the circuit diagram of pull-up priviledge module 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 object of the present invention, technical scheme and advantage clearly understand, 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, be not intended to limit the present invention.

Embodiment one

For convenience of description, external power input ACIN is labeled as ACIN, and 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, 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 and judges signal end, switched charge module.

See 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 and described charging enable signal end, described powered battery judge that signal end, described battery-end BAT, reference power source end REF are connected, and export charging voltage error signal to described Pulse width modulation module.

Described charging current control module and described charging enable signal end, described powered battery judge signal end, described reference power source end REF is connected, receive the current signal ISENSE of the power inductance feedback of described switch power level, export battery charging current error signal to described Pulse width modulation module.

With described charging enable signal end, described powered battery, described pulse width control module judges that signal end is connected, output pulse width modulation signal is described switched charge control logic module extremely, for described charging voltage error signal is converted to pulse width modulating signal.

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 the first electric capacity C1, one end ground connection of the first electric capacity C1.

Described switched charge control logic module and described charging enable signal end, described powered battery judge that signal end, described switch power level, described Pulse width modulation module are connected, receive the pulse width modulating signal exported by described Pulse width modulation module, and control the conducting pulsewidth of described high-side power switch pipe and described low-side power switch pipe according to described pulse width modulating signal.

See Fig. 2, as a kind of embodiment, described charging voltage control module comprises the first differential amplifier, the first resistance R1 and the second resistance R2.

One end of first resistance R1 is connected with described battery-end BAT, and the other end is connected with one end of the second resistance R2, the tie point of the first resistance R1 and the second resistance R2 as the anode input CHFB of the first differential amplifier, the other end ground connection of the second resistance R2.

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

Described charging enable signal CHGEN and described powered battery judge that signal USEBAT is connected to two Enable Pins of described first differential amplifier.

Such connected mode makes cell voltage VBAT obtain anode input voltage CHFB through the first resistance R1 and the second resistance R2 dividing potential drop, and negative input end connects reference voltage V _rEF, thus to through the cell voltage VBAT of dividing potential drop and reference voltage V _rEFcarry out differential amplification.Once find that VBAT is more than V _rEF, then charging voltage error signal can rise; If VBAT is less than V _rEF, charging voltage error signal can decline.

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

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

Described charging enable signal CHGEN and described powered battery judge that signal USEBAT is connected to two Enable Pins of described second differential amplifier.

Once find that ISENSE is more than V _rEF, then battery charging current error signal can rise; If ISENSE is less than V _rEF, battery charging current error signal can decline.

See Fig. 4, as a kind of embodiment, described Pulse width modulation module comprises the 3rd differential amplifier, the first comparator, superpositing unit, the second electric capacity C2, the 3rd electric capacity C3, the 4th electric capacity C4, the 3rd resistance R3, the 4th resistance R4 and the 5th resistance R5.

Described superpositing unit is by described charging voltage error signal, described battery charging current error Signal averaging.

One end of described 3rd resistance R3 is connected with the output of described superpositing unit, and the other end of described 3rd resistance R3 is connected with the negative input end of described 3rd differential amplifier, and the positive input terminal of described 3rd differential amplifier is connected with described reference power source end REF.One end of described second electric capacity C2 is connected with the output of described superpositing unit, and the other end of described second electric capacity C2 is connected with one end of described 4th resistance R4, and the other end of described 4th resistance R4 is connected with the negative input end of described 3rd differential amplifier.

One end of described 5th resistance R5 is connected with the negative input end of described 3rd differential amplifier, the other end of described 5th resistance R5 is connected with one end of described 3rd electric capacity C3, and the other end of described 3rd electric capacity C3 is connected with the output of described 3rd differential amplifier.One end of described 4th electric capacity C4 is connected with the negative input end of described 3rd differential amplifier, and the other end is connected with the output of described 3rd differential amplifier.

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

Charging voltage error signal, battery charging current error signal are applied, then be input to the compensation be made up of 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, 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 judge that signal USEBAT is connected to two Enable Pins (not shown in Fig. 4) of described 3rd differential amplifier.

Once in battery charging current error signal, charging voltage error signal, any one is increased beyond V _rEF, all will the error signal VEA of the output of the 3rd differential amplifier be declined, because pulse-width signal duty ratio equals the ratio of VEA and triangular wave amplitude VSAW, namely thus cause the duty ratio of pulse-width signal to decline, switching charge-current is declined.

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 is connected with described switched charge control logic with the grid of described N-channel MOS pipe.

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 is connected with one end of described power inductance with the tie point of described N-channel MOS pipe.

The other end of described power inductance is provided with current detection circuit, flows through the electric current of power inductance and the current signal ISENSE detected is passed to described charging current control module in order to detection.

Described switched charge module, by regulating the duty ratio of the conducting of described high-side power switch pipe and low-side power switch pipe, controls charging current and charging target voltage.When power source loads ability is 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 of inductance and high-end P channel MOS tube composition.

See 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 judge signal USEBAT and clock frequency, control the turn-on and turn-off of high-side power switch pipe and low-side power switch pipe.Described switched charge control module is also provided with self adaptation chronograph mechanism, coordinate with current detection circuit primarily of controlled timer, the actual charge current size that controlled timer detects according to current detection circuit, change the timing length of timer, or change the frequency of timer clock signal, thus effectively avoid actual charge current to be less than problem that setting charging current causes charging time-out.

Described second comparator or digital to analog converter are connected with described reference power source end REF, described charging Enable Pin and described current detection circuit connect, and 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 simultaneously receive clock frequency signal and current data signal or electric current comparison signal, export charging timeout signal to described power tube control logic unit.

See Fig. 6, as a kind of embodiment, described controlled timer comprises two or more frequency divider and multiselect one MUX and timer.

The input of described multiple frequency divider 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 make the ascending series of equal difference with the inverse of frequency divider number.Even have n frequency divider, then 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, exports timer clock frequency to described timer.

Described timer is also connected with described charging Enable Pin.

The course of work of described controlled timer is, clock source is converted to the clock signal of different frequency by the frequency divider of multiple different divide ratio, outputs to multiselect one MUX MUX.Digital to analog converter ADC converts the charging current detected to digital signal both charging current data, outputs to multiselect one MUX, selects the frequency of corresponding charging current, exports timer clock frequency to counter.If charging current diminishes, the charging current data that ADC sends diminishes thereupon, and charging current data controls multiselect one MUX and selects lower timer frequency to export.Therefore, timer clock frequency changes along with the change of charging current.Timer clock Frequency downshift is equivalent to the time span extending timer.Timer accepts timer clock frequency, once charging enable signal CHGEN=1, timer starts timing.Thus achieve timer with size of current change and the function of dynamic change.

Described power tube logic control element receives charging enable signal CHGEN, powered battery judges signal USEBAT and described pulse width modulating signal and the timeout signal that charges, export high-side power switch pipe and control signal to described high-side power switch pipe, export low-side power switch pipe and control signal to described low-side power switch pipe.

See Fig. 7, as a kind of embodiment, described power tube logic control element is by trigger D1, first with door AN1, second with door AN2, the 3rd and door AN3, first or door OR1, second or door OR2, 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 composition.

Described powered battery judge signal USEBAT after the 4th inverter I4 is anti-phase with described charging enable signal CHGEN and described charging timeout signal as described first with three input end signals of door AN1, first with the output end signal of door AN1 and described clock frequency signal as described second and two input end signals of door AN2, described first with the output end signal of door AN1 after the first inverter I1 is anti-phase with described pulse width modulating signal as described first or two input end signals of door OR1, described second S being connected to described trigger D1 with the output end signal of door AN2 holds, 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 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 first driving stage B1, the output end signal of described first driving stage B1 is described high-side power switch pipe control signal, 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 door AN1 and the output end signal of the first driving stage B1 as the described 3rd with three input end signals of door AN3, described 3rd is connected to the input of described second driving stage B2 with the output end signal of door AN3, the output end signal of described second driving stage B2 is described low-side power switch pipe control signal, 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 the trigger of other types according to actual conditions.

The course of work of described power tube logic control element is: when the enable signal CHGEN of charging is 0 or powered battery judges that signal USEBAT is 1, first and the output EN of door AN1 be zero.Then trigger D1 exports is zero, and high-side power switch pipe control signal is 1, and high-side power switch pipe (PMOS) keeps turning off; Meanwhile, low-side power switch pipe control signal is 0, and low-side power switch pipe (NMOS tube) keeps turning off.When the enable signal CHGEN that charges is 1 while, powered battery judges that signal USEBAT is zero, EN is 1.Trigger D1 is put 1 by clock signal pulse, then high-side power switch pipe control signal is 0, the conducting of high-side power switch pipe, and low-side power switch pipe control signal is 0 simultaneously, and low-side power switch pipe keeps turning off; Once pulse width modulating signal is 1, then first or door OR1 export be 1, trigger D1 export be zero, then high-side power switch pipe control signal is 1, high-side power switch pipe turn off, low-side power switch pipe control signal is 1, the conducting of low-side power switch pipe.

Wherein second or door OR2 effect be, when low-side power switch pipe control signal is 1, high-side power switch pipe control signal is kept to be 1, high-side power switch pipe is kept to turn off, prevent high-side power switch pipe and the conducting simultaneously of low-side power switch pipe, cause system power supply end VSYS to be produced to the big current on ground by high-side power switch pipe and low-side power switch pipe.Wherein the 3rd be with the effect of door AN3, when high-side power switch pipe control signal is 0, low-side power switch pipe control signal is kept to be 0, low-side power switch pipe is kept to turn off, prevent high-side power switch pipe and the conducting simultaneously of low-side power switch pipe, cause system power supply end VSYS to be produced to the big current on ground by high-side power switch pipe and low-side power switch pipe.

In the prior art, in order to ensure lithium cell charging safety, lithium battery charger generally all can set a charging safety timer, once the charging interval arrives the timer sets time, and charging process not yet terminates, charger will stop charging, and export charging abnormal end signal, occur to prevent charging fortuitous event, but because input power driving force is often likely less than charging, electric current is set, even if input power driving force is enough, also input power driving force may be greater than due to system power consumption and charging current sum, cause actual charge current less than normal, charging interval is elongated, even exceed the setting-up time of timer, charger is caused to stop charging, and mistake send charging abnormal end signal.

The charging current detected is converted into digital signal by the digital to analog converter ADC of switched charge module of the present invention, or compared by the current value of the second comparator by the charging current detected and setting, the length of automatic change timer, or change counter clock frequency, the length of the charging time out timer of lithium battery is changed with charging current, works as I _cHGwhen being reduced to close to zero current, timer can keep stopping timing.

Preferably; described switched charge module also comprises battery overheat protector module and chip over-temperature protection module; when chip temperature or battery temperature exceed safe working temperature scope; automatically will reduce charging current or automatically stop charging, until chip temperature or battery temperature are returned within the scope of safe working temperature.

The charging time out timer length of traditional lithium battery charger is fixed, and can not adjust the clock frequency of timing length and timing along with the size of charging current.Due to external power source ability I _dRIVEfixing, along with system power consumption I _sYSchange, I _dRIVEand I _sYS+ I _cHGrelative size when changing, I _cHGcan along with I _sYSchange and change, working as I _dRIVE< I _sYStime, charging current even can be reduced to zero.The danger of mistake time-out can be there is in therefore traditional timer.Therefore the controlled timer changing timing length with charging current in the present invention, effectively prevent because system power consumption causes the charging interval to elongate the problem of the timer mistake time-out brought.

A kind of switched charge circuit provided by the present invention, do not need software programming, pass through hardware implementing completely, effectively solve in prior art the problem of the enforcement complexity existed, solve simultaneously and adopt linear-charging mode to carry out large current charge and the problem such as chip heating, timer mistake time-out that causes.

Embodiment two

See Fig. 8, as a kind of embodiment, described power-supply management system comprises the first voltage comparison module, the second voltage comparison module, Logic control module, the first voltage maintains module, the second voltage maintains module, the first switch element, second switch unit, reference power source end REF, external power 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 the reference voltage that described power-supply management system is changed and compared.

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

Described first voltage comparison module is connected with described external power input ACIN and described reference power source end REF, compares external power input voltage V _aCINwith battery terminal voltage V _bAT, export external power source useful signal ACINVALID to described Logic control module.

Described second voltage comparison module is connected with described system power supply end SYS and described battery-end BAT, comparison system terminal voltage V _sYSwith battery terminal voltage V _bAT, export powered battery and judge that signal USEBAT is to described Logic control module.

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

See Fig. 9, as a kind of embodiment, described first voltage maintains module, is connected to reference power source end REF, external power input ACIN, export the first voltage and maintain signal to the first switch element, comprise the 6th resistance R6, the 7th resistance R7 and the 4th differential amplifier.The positive input terminal of the 4th differential amplifier is connected to reference power source.

External power source input voltage ACIN is after the dividing potential drop of the 6th resistance R6 and the 7th resistance R7, and the dividing potential drop ACDIV obtained is connected to differential amplifier negative input end.Because so the ME for maintenance value of external power source input voltage ACIN can be arranged by the dividing ratios of the 6th resistance R6 and the 7th resistance R7 and reference power source.Differential amplifier output VO export the first voltage maintain signal both the first voltage maintain the output signal of module.

First voltage maintains signal and is connected to the grid of the first PMOS or the base stage of the first PNP pipe.As external power source input voltage V _aCINdecline, cause ACDIV to be less than V _rEF, make the first voltage maintain signal and rise, because the grid voltage of the first PMOS rises, therefore make the resistance of the first PMOS increase, the electric current flowing through the first PMOS is reduced, thus maintains ACIN voltage in set point.

See Figure 10, as a kind of embodiment, described first voltage transformation module is connected to external power input ACIN, reference power source end REF, system power supply end SYS, exports the first voltage transitions and controls signal to described first switch element.First voltage transformation module comprises the 8th resistance R8, the 9th resistance R9 and the 5th differential amplifier composition.The negative input end of the 5th differential amplifier is connected to reference power source.

System power source voltage VSYS is after the dividing potential drop of the 8th resistance R8 and the 9th resistance R9, and the dividing potential drop FB obtained is connected to differential amplifier negative input end.Because so VSYS voltage can be arranged by the ratio of the 8th resistance R8 and the 9th resistance R9 dividing potential drop and reference power source.5th differential amplifier output VO exports the output signal of the first voltage conversion signal both the first voltage transformation module.

First voltage conversion signal is connected to the grid of the first PMOS or the base stage of the first PNP pipe.When system power supply end SYS voltage VSYS declines, cause FB to be less than VREF, voltage transitions control signal is declined, because the grid voltage of the first PMOS declines, therefore make the resistance of the first PMOS reduce; When system power supply end SYS voltage VSYS rises, cause FB higher than VREF, make the first voltage conversion signal increase, because the grid voltage of the first PMOS rises, therefore make the resistance of the first PMOS increase.5th differential amplifier makes system power supply end SYS voltage VSYS reach dynamic equilibrium, makes FB equal VREF, thus maintains 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 second switch pipe, and described second switch pipe is the second PMOS or the second PNP pipe.

When not having external power source to input, second switch cell conduction is that system power supply end SYS powers, and when there being external power source to input, second switch unit is closed.Once find that external power source is not enough to support system power consumption, powered battery path will conducting, powers together with external power source for system power supply end SYS.

Described second voltage maintains model calling in system power supply end SYS and reference power source end REF, and exports the second voltage maintenance signal to 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 the charging enable signal CHGEN exported by described Logic control module and the second voltage maintenance signal being judged signal USEBAT by the powered battery of described second voltage comparison module output and exported by described second voltage maintenance module.

The internal structure of the switched charge module of the present embodiment is similar to embodiment one, repeats no more.See Figure 10, wherein, the present embodiment and embodiment one unlike, described second voltage maintains 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 maintain signal and are superposed 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 compares V _aCINand V _bATheight, work as V _aCINhigher than V _bATduring certain value, export external power source useful signal ACINVALID to Logic control module.When having external power source input and battery-end BAT to connect battery, because general external input power will possess the ability charged the battery, external input power voltage must be met higher than battery-end BAT voltage.As input power terminal voltage signal V _aCINwith battery-end BAT voltage signal V _bATmeet relation V _aCIN>=V _bAT+ Δ V1, wherein Δ V1 represents the difference of a d. c. voltage signal, do not do special restriction to the difference of d. c. voltage signal herein, only represent that input power terminal voltage signal and battery-end BAT voltage signal exist a difference, the difference of d. c. voltage signal can value such as 0.2V.Work as V _aCIN>=V _bATwhen+Δ V1 relation meets, the first voltage comparison module output signal ACINVALID=1, otherwise output signal ACINVALID=0.

Second voltage comparison module compares V _bATand V _sYSthe height of voltage, exports powered battery signal (USEBAT) to Logic control module.As battery-end BAT voltage signal V _bATwith system power supply end SYS voltage signal V _sYSmeet relation V _bAT>=V _sYS+ Δ V2, wherein Δ V2 represents the difference of a d. c. voltage signal, do not do special restriction to the difference of d. c. voltage signal herein, only represent that battery-end BAT voltage signal and system power supply end SYS voltage signal exist a difference, the difference of d. c. voltage signal can value such as 0.04V.Work as V _bAT>=V _sYSwhen+Δ V2 relation meets, the second voltage comparison module output signal U SEBAT=1, otherwise output signal U SEBAT=0.

Work as V _bAT>=V _sYSduring+Δ V2, show that external power source scarce capacity is to provide system power consumption, need the conducting of battery auxiliary power supply path.Now, switched charge module reception battery auxiliary power supply signal makes the high-end MOS conducting in switched charge module, and low side metal-oxide-semiconductor is closed, closing switch charge function, make high-end MOS and inductance composition auxiliary power supply path, this path will be powered from battery to system power supply end SYS simultaneously.

Logic control module receives powered battery and judges signal USEBAT and external power source useful signal ACINVALID, exports external power source and selects signal SELACIN, powered battery to select signal SELBAT and charging enable signal CHGEN.Judge that signal USEBAT state is different according to the external power source useful signal ACINVALID received with powered battery, be divided into three kinds of situations: (1), as ACINVALID=0, regardless of USEBAT why state, output is all SELBAT=1, CHGEN=0; (2) work as ACINVALID=1, during USEBAT=0, export as SELBAT=0, CHGEN=1; (3) work as ACINVALID=1, during USEBAT=1, export as SELBAT=1, CHGEN=0.

Described first switch element is a PMOS or PNP pipe.First voltage maintains module and receives external power source selection signal SELACIN, when external power source selects signal SELACIN to be high, to outside power input voltage V _aCINand V _rEFdifference amplify, export the first voltage and maintain the grid of signal to the first PMOS or the base stage of the first PNP pipe, change the resistance of PMOS or PNP pipe, by V _aCINmaintain setting voltage.As the V received _aCINduring decline, cause the first voltage to maintain signal and rise, PMOS grid voltage rises, make the electric conduction resistive of PMOS large, PMOS conducting resistance rises and the electric current flowing through PMOS drain electrode is declined, and the electric current namely flowing to VSYS by PMOS from ACIN declines, thus hinders V _aCINvoltage signal declines.When voltage signal drops to and reference voltage signal V _rEFtime equal, the closed feedback loop that input voltage signal maintains signal and PMOS formation reaches dynamic equilibrium, thus maintains V _aCINin set point.

First power transfer module receives external power source and selects signal SELACIN, when external power source selects signal SELACIN to be high, by V _sYSand V _rEFdifference amplify, output voltage changeover control signal, to the first PMOS grid and the first PNP pipe base stage, regulates the resistance of PMOS or PNP, by V _sYSmaintain set point and ensure system power supply.As reception V _sYSdecline time, cause voltage transitions control signal to decline, the resistance of the first PMOS declined, increase drain current, thus hinder V _sYSvoltage drop.

In like manner, the second voltage maintains module by V _sYSand V _rEFdifference amplify, export second voltage maintain signal to switched charge module, work as V _sYSdrop to the safe operating voltage V of the required setting of guarantee system safety work of setting _{sYS SAFE}after, the second voltage maintains signal and will decline.

The duty ratio of charging reduces, reduces charging current, thus maintain V after maintaining signal by the second voltage that the Pulse width modulation module of switched charge module receives decline _sYSto the safe operating voltage V of setting _{sYS SAFE}, ensure the normal work of system.

Described switched charge module controls by charging signals CHGEN, through processes such as trickle charge, constant current charge, constant voltage charges, is full of by battery, and then stop charging, waiting system meets the condition of again charging.As the charging enable signal CHGENCHGEN=0 received, charge control module charge closing process; As the charging enable signal CHGENCHGEN=1 received, charge control module starts charging process.

The power-supply management system that the present embodiment provides, when there being external power source to input, starts working, if the current driving ability I of external input power _dRIVEbe less than system consumption electric current I _sYSwith the charging current I of battery _cHGsum, that is: I _dRIVE< I _sYS+ I _cHG, system power supply end SYS voltage V can be caused _sYSdecline.Above-mentioned power-supply management system will according to different applicable cases autobalance charging and discharging electric currents, and ensure system worked well, its detailed process is described below.

If battery-end BAT voltage V _bATbe greater than system safety operating voltage V _{sYS SAFE}, then along with V _sYSdecline, V _sYScan first drop to close to V _bAT, because the high-side power switch pipe of switched charge module exists conducting resistance, so the charged electrical flowing to battery-end BAT through 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 now still there is I _dRIVE< I _sYS+ I _cHG, then V _sYSalso can continue to drop to compare V _bATalso low.

Now the second voltage comparison module then output signal U SEBAT=1; Logic control module outputs signal CHGEN=0, SELBAT=1 according to ACINVALID=1, USEBAT=1, and Logic control module now will make second switch unit (the second PMOS) conducting, make battery to system power supply end SYS supplementary power.The signal that Simultaneous Switching charge control module receives is CHGEN=0 and charge closing process, simultaneously by the high-side power switch pipe conducting of switched charge power stage, and turn off low-side power switch pipe, thus make the auxiliary power supply path conducting of switch power level and power inductance composition.

Now the second PMOS and the conducting simultaneously of switched charge auxiliary power supply path, form the path of battery to system power supply together, reduce the resistance of supply access like this, improve the efficiency of system power supply conversion.So now input power terminal voltage V _aCINwith battery-end BAT voltage V _bATsupply path conducting simultaneously, to system power supply end SYS voltage V _sYScooperated power supply, the system power supply end SYS undertension that the system of ensure that can not cause because external input power current driving ability is not enough makes system cisco unity malfunction.

If battery-end BAT voltage signal V _bATbe less than system safety operating voltage V _{sYS SAFE}, then along with system power supply end SYS voltage signal V _sYSdecline, V _sYScan first drop to close to V _{sYS SAFE}.Now the difference of the second voltage maintenance modular system to power end voltage and reference power source end REF voltage is amplified, export the second voltage and maintain signal to switched charge module, after switched charge module receives the second voltage maintenance signal of decline, 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 now I _dRIVE< I _sYS+ I _cHGstill meet, then V _sYSalso can continue to decline, until than battery-end BAT voltage signal V _bATalso low.Now the second voltage comparison module then output signal U SEBAT=1; Logic control module outputs signal CHGEN=0, SELBAT=1 according to ACINVALID=1, USEBAT=1, makes the second PMOS conducting simultaneously.And after switched charge module receives CHGEN=0, by charge closing process, make high-side power switch pipe normal open, and turn off low-side power switch pipe, make the auxiliary power supply path conducting between system power supply end SYSSYS and battery-end BATBAT.Now system power supply end SYS voltage signal V _sYSsource 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 according to system power consumption and external power source ability, and dynamic management charging current and system power supply path, meet the operation that system safety is stable.Wherein, external power source priority, higher than powered battery priority, when there being external power source to insert, preferentially uses external power source; System power supply priority is higher than battery charging priority, the supply current of external power source preferentially meets system need for electricity, residue power supply capacity is used for battery charging, when system power consumption curent change, according to the size of system power consumption and external power source ability dynamic conditioning charging current; When external power source is not enough to support system power consumption, starting powered battery path is system power supply, and now external power source insufficient section is provided by battery.

Under the power-supply management system of the present embodiment has multiple input sources situation at the same time, preferential use external power source is system power supply, under the prerequisite of preferential guarantee system power supply, remaining external power source electric current after meeting system electricity consumption is used for charging the battery, according to external power load ability and system electricity consumption situation dynamic assignment charging current, can prevent external input power be not enough to simultaneously give system power supply and charge the battery time, and the problem that the system caused cannot normally work, also solve simultaneously timer mistake time-out and linear-charging electric current little, inefficient problem.

Embodiment three

Shown in Figure 12, as a kind of embodiment, power-supply management system of the present invention comprises the first voltage comparison module, the second voltage comparison module, Logic control module, the first voltage maintains module, the second voltage maintains module, the first switch element, second switch unit, reference power source end REF, external power 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 is connected with described battery-end BAT, described reference power source end REF and described second switch unit.

Linear-charging model calling, in second switch unit, controls charging current and charging voltage.In this power-supply management system, linear-charging module and switched charge module cooperating.First switched charge circuit enabled by charging circuit, simultaneously monitoring current size, when battery is close to when being full of, charging current will reduce, when charging current is less than preset value, first closing switch charging circuit, then starting linear charging block is battery charging.

During linear-charging module work, do not disturb system power source voltage, but efficiency is lower, the electric energy loss in chip is very high, and these electric energy losses will convert heat to, causes when large current charge, chip is generated heat 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 source voltage.Therefore when the technical solution used in the present invention is for detecting that charging current is very little, system, by automatic cut-off switch charging module, is opened linear-charging module and is charged the battery, because charging current is little, therefore chip heating is little, it also avoid the interference of switched charge to system power source voltage simultaneously; When detecting that charging current becomes large, automatically closing linear charging module, opening switched charge module and charge the battery, utilize the ability of switched charge high efficiency and large current charge, chip can be avoided to generate heat, make battery be full of electricity fast simultaneously.

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

In the present embodiment, current detection circuit is provided with at external power input ACIN, the current signal ISENSE detected is connected to the positive input terminal of the 6th differential amplifier by described current detection circuit, the negative input end of the 6th differential amplifier connects reference power source end REF, and the output VO of the 6th differential amplifier exports the first Current limited Control signal.First Current limited Control signal transmission is to the grid of described first PMOS or the base stage of the first PNP pipe.To after detecting that current signal ISENSE exceedes reference power source terminal voltage VREF, the first Current limited Control signal rises, and the resistance of the first PMOS or the first PNP pipe is increased, and the electric current of the collector electrode flowing through the first PMOS drain electrode or the first PNP pipe is reduced.

Described second current limliting module is connected with described battery-end BAT and second switch unit, receives the current signal ISENSE fed back by described battery-end BAT.Comprise the 7th differential amplifier.Described battery-end BAT is also provided with a current detection circuit, the current signal ISENSE detected is passed to the positive input terminal of the 7th differential amplifier by described current detection circuit, the negative input end of the 7th differential amplifier is connected with described reference power source end REF, and output VO exports the grid of the second current limit signal to the second PMOS or the base stage of the second PNP pipe.

See Figure 14 and Figure 15, as a kind of embodiment, first switch element of the present embodiment comprises the first switching tube and the first pull-up priviledge module, and described first switching tube is the first PMOS or the first PNP pipe.The output signal that first voltage maintains module, the first voltage transformation module and the first current limliting module adopts after the preferential mode of pull-up superposes, and is connected to the base stage of a PMOS grid or the first PNP pipe.External power source input voltage ACIN drops to ACIN ME for maintenance, VSYS exceedes set point and the first PMOS drain current exceedes any one appearance in these three kinds of situations of set point, capital causes the grid voltage of the first PMOS to be driven high, increase the resistance of the first PMOS, prevent these three kinds of fortuitous events from occurring.

See Figure 15, as a kind of embodiment, described first pull-up priviledge module comprise the 3rd PMOS, the 4th PMOS, the 5th PMOS and current direction point to the current source of (direction as shown be downward) form.A, B, C are three inputs of described pull-up priviledge module, and VO is output.When A point signal declines, then the resistance of the PMOS of A point connection declines, and exceedes the electric current of current source, VO will be made to increase once this PMOS resistance pull-up current ability.Therefore any one signal of A, B, C declines, and when causing the pull-up current of corresponding PMOS to exceed the electric current of downward current source, VO all will be caused to rise.

As a kind of embodiment, described second switch unit comprises second switch pipe and the second pull-up priviledge module, described second switch pipe is the second PMOS or the second PNP pipe, the structure of described second pull-up priviledge module is with reference to the first pull-up priviledge module, the number of the PMOS of the second pull-up priviledge module arranges the number depending on input signal, those skilled in the art can change flexibly according to the technical conceive of the application, are not further qualified herein.

Native system is that external power source ACIN supply path provides current-limiting function by arranging the first current limliting module, and arrange the second current limliting module is that the supply path of battery-end BAT provides current-limiting function simultaneously.When detecting that the electric current flowing through supply path has exceeded current limliting set point, the first current limliting module or the second current limliting module are by I _senseamplify with the difference of reference signal, output current limiting control signal, to the grid of supply path PMOS, increases the resistance of PMOS, makes electric current be limited in security settings electric current.Because the resistance of supply path PMOS increases, V will be caused _sYSdecline, work as V _sYSdrop to system closedown voltage V _{sYS OFF}after, system will close supply path, until short circuit condition is cancelled, supply path can be opened, thus burns when effectively preventing chip to be shorted.Owing to often occurring in the application exporting the wrong usage being shorted to ground, therefore two supply paths all have current-limiting function is the effective and indispensable safety measure of when wrong short circuit one of system, can can be limited in safe range by anti-locking system electric current when short circuit, guarantee system can not be burnt.

Embodiment four

See Figure 16, owing to usually having adapter input port and USB interface two external power source input sources in the electronic device.Therefore the solution simultaneously with external adapter input port and USB interface is present embodiments provided.

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

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

The operation principle that described tertiary voltage maintenance module and described first voltage maintain module is similar, be connected with described VBUS input, described reference power source end REF, receive the VBUS exported by described Logic control module and select signal, export tertiary voltage and maintain signal to described 3rd switch element.

The operation principle of described second voltage transformation module and described first voltage transformation module is similar, be connected with system power supply end SYS, reference power source end REF, receive the VBUS exported by described Logic control module and select signal, export the second voltage conversion signal to described 3rd switch element.

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

First voltage comparison module of the power-supply management system of the present embodiment, the second voltage comparison module, Logic control module, the first voltage maintain module, the second voltage maintains module, the first switch element, second switch unit, reference power source end REF, external power input ACIN, system power supply end SYS, battery-end BAT, switched charge module and the first voltage transitions, the annexation of these comprising modules and the course of work, with reference to previous embodiment, are not repeating.The following detailed description of the course of work of USB interface pertinent modules.

Tertiary voltage comparison module is by V _vBUSand V _bATrelatively, V is exported _vBUSpower supply useful signal VBUSVALID.Second voltage transformation module is by V _sYSand V _rEFdifference amplify, output voltage changeover control signal, to the grid of VBUS path P metal-oxide-semiconductor (the 3rd PMOS), makes VBUS be transformed into V _sYS.When USB connects, V must be ensured _vBUShigher than secure connection voltage V _vBUSHOLD, once because system power consumption causes V _vBUSdrop to V _vBUSHOLDbelow, USB will be caused to go offline.Therefore tertiary voltage maintains module and detects V _vBUS, work as V _vBUSdrop to USB line safe voltage V _vBUSHOLD, tertiary voltage will be exported and maintain module to VBUS path P metal-oxide-semiconductor grid, and increase the resistance of PMOS, reduce the electric current of VBUS to SYS end, make V _vBUSmaintain V _vBUSHOLDcan not continue to decline, thus ensure that USB can not go offline.

When to have ACIN input and VBUS input simultaneously, preferentially use ACIN power consumption, guarantee system can not take out electricity from VBUS, causes VBUS to connect and occurs extremely.If once find that ACIN is not enough to back-up system power consumption and causes V _sYSdrop to V _{sYS SAFE}, VBUS supply access will start, and now ACIN and VBUS is system power supply jointly, ensures system worked well.If I _aCIN+ I _vBUS< I _sYS, V _sYSwill drop to and be less than V _bAT, once V _bAT>=V _sYS+ Δ V2 condition meets, system will make the conducting of powered battery path P metal-oxide-semiconductor, and opens the auxiliary power supply path of switched charge, and now supply current is provided jointly by ACIN, VBUS and BAT tripartite, ensure system worked well, the normal connection of USB can also be ensured simultaneously.Therefore, the present invention is that the normal connection of USB provides double safeguard protection.

Technical scheme disclosed in present embodiment, in order to system stability work can be ensured, the safe charging to lithium ion battery can be realized simultaneously, there is lithium battery power supply, when simultaneously having again two-way external power source input, use priority is divided to three kinds of power supplies and rational regulation and control have been done to each self-charging of three kinds of power supplies, the course of work.

When there being external power source, preferential use external power source is system power supply, and the priority that simultaneity factor is powered is also higher than the priority of charging.Under the prerequisite of preferential guarantee system power supply, be used for charging the battery by the remaining external power source electric current after meeting system electricity consumption, therefore power-supply management system needs according to external power load ability and system electricity consumption situation dynamic assignment charging current.Simultaneously when having AC adapter and the input of USB interface external power source, AC adapter powers priority higher than USB power source, if because USB power source is dragged down by load current, can cause the failure of USB line.Therefore when there is AC adapter and USB power source input at the same time, preferentially power from AC adapter, ensure that USB power source voltage is normal, make USB line exception can not occur; If when AC adapter is not enough to feed system power consumption, then can enable USB power source, now AC adapter and USB power source are simultaneously to system power supply, ensure system worked well; Also be not enough to meet system power consumption requirements if AC adapter and USB power simultaneously, just start powered battery, now system will by AC adapter, USB and battery three-way power simultaneously to system power supply, not only can meet the power consumption requirements of system works, can also ensure that USB power source voltage can not drag down because of system power consumption, ensure that USB line is normal.

Power-supply management system provided by the invention, realize the high efficiency safe charging of lithium battery big current, and automatically select 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, ensure system worked well.Simultaneous Switching charging module also has the self-reacting timer with actual charge current, avoids the problem of the actual charge current charging time-out caused less than normal.

Finally it should be noted that obviously, those skilled in the art can carry out various change and modification to the present invention and not depart from the spirit and scope of the present invention.Like this, if these amendments of the present invention and modification belong within the scope of the claims in the present invention and equivalent technologies thereof, then the present invention is also intended to comprise these change and modification.

Claims (13)

1. a switched charge circuit, comprise system power supply end, battery-end, reference power source end, charging enable signal end and powered battery and judge signal end, it is characterized in that, also comprise 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;

With described charging enable signal end, described powered battery, described switched charge control logic module, described charging voltage control module, described pulse width control module all judge that signal end is connected;

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

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

Described switch power level is also 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 judges signal end with described charging enable signal end, described powered battery, described reference power source end is connected, receive the current signal of the power inductance feedback of described switch power level, export battery charging current error signal to described Pulse width modulation module;

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

Described switched charge control logic module comprises power tube control logic unit, controlled timer and the second comparator or digital to analog converter;

Described second comparator or digital to analog converter are connected with the power inductance of described reference power source end, described charging Enable Pin and described switch power level, and described second comparator or digital to analog converter 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 simultaneously receive clock frequency signal and current data signal or electric current comparison signal, export charging timeout signal to described power tube control logic unit;

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

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 first resistance is connected with described battery-end, and the other end of described first resistance is connected with one end of described second resistance, the other end ground connection of described second resistance;

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

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

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

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 of described second differential amplifier accesses the current signal fed back by the power inductance of described switch power level, the negative input end of described second differential amplifier is connected with described reference power source, and the output of described second differential amplification exports battery charging current error signal.

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 by described charging voltage error signal, described battery charging current error Signal averaging;

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

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

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

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

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

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

5. switched charge circuit according to claim 1, it is characterized in that, described power tube control logic unit comprise trigger, first and door, second and door, the 3rd with door, first or door, second or door, the first inverter, the second inverter, the 3rd inverter, the 4th inverter, the first driving stage, the second driving stage;

Described powered battery judge signal after the 4th inverter is anti-phase with described charging enable signal and described charging timeout signal as described first with three input end signals of door, first with the output end signal of door and clock frequency signal as described second and two input end signals of door, described first with the output end signal of door after the first inverter is anti-phase with described pulse width modulating signal as described first or two input end signals of door, described second S being connected to described trigger with the output of door holds, described first or the output 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 second driving stage as described second or two input end signals of door, described second or the output of door be connected to the input of described first driving stage, the output end signal of described first driving stage is described high-side power switch pipe control signal, and the output of described first driving stage 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 3rd with three input end signals of door, described 3rd is connected to the input of described second driving stage with the output of door, the output end signal of described second driving stage is described low-side power switch pipe control signal, and the output of described second driving stage is connected to described low-side power switch pipe.

6. switched charge circuit according to claim 1, is characterized in that, described controlled timer comprises two or more frequency divider 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, the corresponding divide ratio of each described frequency divider, the plural described divide ratio that described plural frequency divider is corresponding forms the ascending series making equal difference with the inverse of frequency divider number;

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

Described timer is also connected with described charging Enable Pin.

7. 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 is connected with described switched charge control logic with the grid of described N-channel MOS pipe;

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 is connected with one end of described power inductance with the tie point of described N-channel MOS pipe, and the other end of power inductance is connected with described battery-end.

8. a power-supply management system, comprise the first voltage comparison module, the second voltage comparison module, Logic control module, the first voltage maintains module, the second voltage maintains module, the first switch element, second switch unit, reference power source end, external power 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 the charging enable signal exported by described Logic control module and the second voltage maintenance signal being judged signal by the powered battery of described second voltage comparison module output and exported by described second voltage maintenance module;

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

9. power-supply management system according to claim 8, is characterized in that, also comprises linear-charging module, and described linear-charging module is connected with described battery-end, described reference power source end and described second switch unit.

10. power-supply management system according to claim 8, is characterized in that, also comprises the first current limliting module;

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

11. power-supply management systems according to claim 8, it is characterized in that, also comprise the second current limliting module, described second current limliting module comprises the 7th differential amplifier, the positive input terminal of described 7th differential amplifier accesses the current signal fed back by described battery-end, negative input end is connected with described reference power source end, and output is connected with described second switch unit.

12. power-supply management systems according to claim 10, is characterized in that, described first switch element comprises the first switching tube and the first pull-up priviledge module;

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

Described first pull-up priviledge module comprises the 3rd PMOS, the 4th PMOS, the 5th PMOS and a current source, and the current reference direction of described current source is point to ground by the output of described first pull-up priviledge module;

Described first voltage maintains the output of module, the output of described first voltage transformation module is connected with the grid of the grid of described 3rd PMOS, the grid of the 4th PMOS and the 5th PMOS respectively with the output of the first current limliting module;

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

13. power-supply management systems according to claim 8, is characterized in that, also comprise tertiary voltage comparison module, the second voltage transformation module, tertiary voltage maintenance 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, exports VBUS useful signal to described Logic control module;

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

Described second voltage transformation module is connected with described system power supply end, reference power source end, receives the VBUS exported by described Logic control module and selects signal, export the second voltage conversion signal to described 3rd switch element;

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