CN202334295U - Low-power consumption start-up and under-voltage protection circuit device - Google Patents

Abstract

The utility model relates a low-power consumption start-up and under-voltage protection circuit device. The low-power consumption start-up and under-voltage protection circuit device comprises a start-up voltage detection module and a voltage hysteresis state latch, wherein the start-up voltage detection module is used for detecting power supply voltage of a chip; when the power supply voltage is higher than an upper limit voltage threshold, an enable end outputs enable signals, and the enable signals start a pulse-width modulation (PWM) control module of the chip to allow the chip to normally work; when the power supply voltage is lower than a lower limit voltage threshold, the enable signals close the PWM control module of the chip; and the voltage hysteresis state latch is used for realizing the function of under-voltage protection when the power supply voltage is lower than the lower limit voltage threshold and the enable signals close the PWM control module of the chip. According to the scheme, the power consumption of a start-up resistor of a power supply system of the PWM control module which is integrated with the circuit is reduced by integrating the sub-microampere start-up and under-voltage protection circuit in a switch power chip, the design difficulty of a low-standby power consumption power system is reduced, and the conversion efficiency of the power supply system is improved.

Description

A kind of startup of low-power consumption and under-voltage protecting circuit device

Technical field

The utility model relates to the switch power technology field, and particularly, the utility model relates to a kind of startup and under-voltage protecting circuit device of low-power consumption.

Background technology

Because modern Switching Power Supply grows with each passing day for the requirement of power consumption; And environment protection switch power supply is that all application are necessary; And the hand-hold type of the indication of being not only over and battery power supply system, therefore under the major premise of protection environmental ecology, the energy consumption that reduces power line electric power system and battery power supply system all is absolutely necessary; Concerning China, this more can bring special advantage: the load that reduces the coal fired power generation station.This just not only requires power supply chip control core to possess the low-power consumption characteristic, but also requires it to possess the characteristic that some can further reduce system power dissipation.

Fig. 1 has shown typical application of switching power scheme, wherein a R _StartBe the starting resistance of chip, VCC termination 320V voltage, and the vdd terminal voltage of chip is 18V, flows through R so _StartElectric current be:

$I_{\mathrm{start}}=\frac{\mathrm{VCC}-\mathrm{VDD}}{R_{\mathrm{start}}}$

The starting resistance of traditional chip is generally understood about 1M Ohm, works as the system's power consumption of operate as normal post consumption on this starting resistance so and is:

$P_{\mathrm{diss}}=\frac{{(\mathrm{VCC}-\mathrm{VDD})}^2}{R}=\frac{{(311-16)}^2}{1000000}=87\mathrm{mW}$

Because Energy Star has been put into effect and will be lower than 30mW to modern small-power switching power-supply system standby power consumption; Even be lower than the requirement of 4mW; If so on starting resistance, consumed excessive power consumption; The design difficulty of low-power dissipation system will improve greatly so, and the conversion efficiency of power-supply system also is affected.

Therefore, be necessary to propose the otherwise effective technique scheme, solve the excessive difficult problem of Switching Power Supply power consumption in the prior art.

The utility model content

The purpose of the utility model is intended to solve at least one of above-mentioned technological deficiency, through reducing power-supply system power consumed on starting resistance, has reduced the design difficulty of low standby power loss electric system especially, improves the conversion efficiency of power-supply system.

The utility model embodiment has proposed a kind of startup and under-voltage protecting circuit device of low-power consumption, comprises the status latch that starting resistor detection module and voltage are sluggish,

Said starting resistor detection module is used for the supply power voltage of detection chip, when said supply power voltage is higher than the upper voltage limit threshold value, and Enable Pin output enable signal, the PWM control module of opening chip allows the chip operate as normal; When supply power voltage was lower than the lower voltage limit threshold value, enable signal was closed the PWM control module of chip;

The status latch that voltage is sluggish when supply power voltage is lower than the lower voltage limit threshold value, when enable signal is closed the PWM control module of chip, forms sluggish voltage relationship, realizes the function of chip under-voltage protection.

The utility model embodiment has also proposed a kind of Switching Power Supply, comprises the startup and the under-voltage protecting circuit device of low-power consumption, the PWM controller,

The startup of said low-power consumption and under-voltage protecting circuit device; Be used for according to the said PWM controller of supply power voltage output enable signal controlling; Wherein, when said supply power voltage was higher than the upper voltage limit threshold value, the PWM control module of output enable unblanking chip allowed the chip operate as normal; When supply power voltage was lower than the lower voltage limit threshold value, enable signal was closed the PWM control module of chip, and Switching Power Supply is in the under-voltage protection state simultaneously;

Said PWM controller is used to receive the startup of said low-power consumption and the enable signal and the pwm control signal input of under-voltage protecting circuit device output, and the output signal is realized the switch of power supply.

The such scheme that the utility model embodiment proposes; Start and under-voltage protecting circuit through integrated submicron level in switching power source chip; Thereby the power-supply system power consumed on starting resistance of pwm chip of the utility model circuit that reduced application integration; Reduce the design difficulty of low standby power loss electric system, improved the conversion efficiency of power-supply system.In addition, the such scheme that the utility model proposes, very little to the change of existing Circuits System, can not influence the compatibility of system, and realize simple, efficient.

Aspect that the utility model is additional and advantage part in the following description provide, and these will become obviously from the following description, or recognize through the practice of the utility model.

Description of drawings

Above-mentioned and/or additional aspect of the utility model and advantage are from obviously with easily understanding becoming the description of embodiment below in conjunction with accompanying drawing, wherein:

Fig. 1 is typical application of switching power scheme;

Fig. 2 is the startup and the under-voltage protecting circuit apparatus function module map of the utility model embodiment low-power consumption;

Fig. 3 is the startup and the under-voltage protecting circuit device physical circuit figure of the utility model embodiment low-power consumption;

Fig. 4 is the utility model embodiment application of switching power scheme.

Embodiment

Describe the embodiment of the utility model below in detail, the example of said embodiment is shown in the drawings, and wherein identical from start to finish or similar label is represented identical or similar elements or the element with identical or similar functions.Be exemplary through the embodiment that is described with reference to the drawings below, only be used to explain the utility model, and can not be interpreted as restriction the utility model.

In order to realize the purpose of the utility model, the utility model embodiment has proposed a kind of startup and under-voltage protecting circuit device of low-power consumption, comprises the status latch that starting resistor detection module and voltage are sluggish,

Said starting resistor detection module is used for the supply power voltage of detection chip, when said supply power voltage is higher than the upper voltage limit threshold value, and Enable Pin output enable signal, the PWM control module of opening chip allows the chip operate as normal; When supply power voltage was lower than the lower voltage limit threshold value, enable signal was closed the PWM control module of chip;

The status latch that voltage is sluggish when supply power voltage is lower than the lower voltage limit threshold value, when enable signal is closed the PWM control module of chip, forms sluggish voltage relationship, realizes the function of chip under-voltage protection.

As shown in Figure 2, be the functional block diagram of this circuit module, this circuit mainly can be summed up as the status latch of a detection starting module and a sluggishness with voltage and form.

Particularly, the starting resistor detection module is realized voltage detecting through said starting resistor detection module through comparable chip supply power voltage and chip internal benchmark.

Particularly, the sluggish status latch of voltage comprises at least two inverters.

Fig. 3 has showed that the utility model starts and the under-voltage protecting circuit realization; When chip power, the minimum starting current that let flow is crossed R1 is Imin, and the electric current that when M1 just overturns, flows through the M1 pipe so is I1; The overstating to lead of M1 pipe is Gm1; Turn-on threshold voltage is Vth1, and gate source voltage is VGS1, obtains following equality:

$I_{\min }=\frac{1}{2}\mathrm{Gm}1*(V_{\mathrm{GS}1}-V_{\mathrm{th}1})---\left(1\right)$

Wherein have:

V _GS1＝I _min*R1 (2)

The upset simultaneously of M2 pipe this moment, the overstating to lead of M2 pipe are that Gm2, turn-on threshold voltage are Vth2, and gate source voltage for the VGS2 electric current is:

$I2=\frac{1}{2}\mathrm{Gm}2*(V_{\mathrm{GS}2}-V_{\mathrm{th}2})---\left(3\right)$

Wherein:

V _GS2＝I1*R2 (4)

In conjunction with (1), (2), (3) and (4) formula can in the hope of:

$I_{\min }=\frac{\frac{1}{4}\mathrm{Gm}2*\mathrm{Gm}1*V_{\mathrm{th}1}*R2+\frac{1}{2}\mathrm{Gm}2\mathrm{Vth}2}{\frac{1}{4}\mathrm{Gm}2*\mathrm{Gm}1*R1*R2-1}---\left(5\right)$

Because Gm2*Gm1*R1*R2＞＞1 in the denominator:

$I_{\min }\≈\frac{V_{\mathrm{th}1}}{R1}+\frac{2*V_{\mathrm{th}2}}{(\mathrm{Gm}1*R1*R2)}---\left(6\right)$

Because 2*Vth2＜＜Gm2*R1*R2:

$I_{\min }\≈\frac{V_{\mathrm{th}1}}{R1}---\left(7\right)$

Can find out as starting current Istart during circuit start more than or equal to I min from (7).The vdd voltage of this moment is:

${\mathrm{VDD}}_{\mathrm{start}}=\frac{V_{\mathrm{th}1}}{R1}*R4+V_{\mathrm{bv}1}+V_{\mathrm{bv}2}+V_{\mathrm{bv}3}+V_{\mathrm{th}1}---\left(8\right)$

(8) the VDDstart the utility model in starts the upper voltage limit threshold value of opening with under-voltage protecting circuit.When this start-up circuit operate as normal, because the positive feedback relation between M3 pipe and the M4 pipe, the drain terminal voltage of M3 pipe is dragged down; So the voltage when circuit is closed can be lower than VDDstart; Formed the relation of a sluggishness, realized the function of under-voltage protection, concrete analysis is following:

Suppose that Ioff is the critical current that the utility model starts the R4 that flows through when closing with under-voltage protecting circuit, wherein Gm3 is that overstating of M3 pipe led, and Gm4 is that overstating of M4 pipe led, and Vth3 and Vth4 are respectively the threshold voltage that M3 and M4 manage, and following relation is arranged so:

$I_{\mathrm{off}}=\frac{1}{2}\mathrm{Gm}3*(V_{\mathrm{GS}3}-V_{\mathrm{th}3})---\left(9\right)$

Wherein:

$V_{\mathrm{GS}3}=\frac{1}{2}\mathrm{Gm}4*(I_{\mathrm{off}}*R4-\mathrm{Vth}4)*R5---\left(10\right)$

Can obtain following relation in conjunction with (9) and (10) arrangement:

$I_{\mathrm{off}}=\frac{\frac{1}{4}\mathrm{Gm}3*\mathrm{Gm}4*V_{\mathrm{th}4}*R5-\frac{1}{2}\mathrm{Gm}3*V_{\mathrm{th}3}}{\frac{1}{4}\mathrm{Gm}3*\mathrm{Gm}4*R4*R5-1}---\left(11\right)$

Since Gm3*Gm4*R4*R5＞＞1 in the denominator, therefore:

$I_{\mathrm{off}}\≈\frac{V_{\mathrm{th}4}}{R4}-\frac{2*V_{\mathrm{th}3}}{\mathrm{Gm}4*R4*R5}---\left(12\right)$

Because 2*Vth3＜＜Gm4*R4*R5:

$I_{\mathrm{off}}=\frac{V_{\mathrm{th}4}}{R4}---\left(13\right)$

So the lower threshold voltage in the time of can obtaining start-up circuit and close is:

V _off＝V _th4+V _bv1 (14)

INV1 in this circuit and INV2 are two inverters, and the signal when its effect is used for start-up circuit generation upset is converted into the logical signal of chip, is used for enabling chip remaining circuit module.

The utility model embodiment has also proposed a kind of Switching Power Supply, comprises the startup and the under-voltage protecting circuit device of low-power consumption, the PWM controller.

The startup of low-power consumption and under-voltage protecting circuit device; Be used for according to the said PWM controller of supply power voltage output enable signal controlling; Wherein, when said supply power voltage was higher than the upper voltage limit threshold value, the PWM control module of output enable unblanking chip allowed the chip operate as normal; When supply power voltage was lower than the lower voltage limit threshold value, enable signal was closed the PWM control module of chip, and Switching Power Supply is in the under-voltage protection state simultaneously.

The PWM controller is used to receive the startup of said low-power consumption and the enable signal and the pwm control signal input of under-voltage protecting circuit device output, and the output signal is realized the switch of power supply.

Particularly, the startup of said low-power consumption and under-voltage protecting circuit device comprise starting resistor detection module and the sluggish status latch of voltage.

The starting resistor detection module is used for the supply power voltage of detection chip, when said supply power voltage is higher than the upper voltage limit threshold value, and Enable Pin output enable signal, the PWM control module of opening chip allows the chip operate as normal; When supply power voltage was lower than the lower voltage limit threshold value, enable signal was closed the PWM control module of chip;

The status latch that voltage is sluggish when supply power voltage is lower than the lower voltage limit threshold value, when enable signal is closed the PWM control module of chip, forms sluggish voltage relationship, realizes the function of chip under-voltage protection.

Particularly, said starting resistor detection module is realized voltage detecting through said starting resistor detection module through comparable chip supply power voltage and chip internal benchmark.Particularly, the sluggish status latch of said voltage comprises at least two inverters.

Fig. 4 is the application example that has used this startup and under-voltage protecting circuit; When the supply power voltage of chip was higher than the upper voltage limit threshold value, Enable Pin output enable signal allowed the chip operate as normal; When supply power voltage was lower than the lower voltage limit threshold value, enable signal was closed the PWM control module of chip.This module can well be compatible with traditional application scheme in the middle of using, and the unique place that needs to change of the system that is to say is exactly to strengthen starting resistance to reduce this ohmically power consumption.

The such scheme that the utility model embodiment proposes; Start and under-voltage protecting circuit through integrated submicron level in switching power source chip; Thereby the power-supply system power consumed on starting resistance of pwm chip of the utility model circuit that reduced application integration; Reduce the design difficulty of low standby power loss electric system, improved the conversion efficiency of power-supply system.In addition, the such scheme that the utility model proposes, very little to the change of existing Circuits System, can not influence the compatibility of system, and realize simple, efficient.

Though specify about example embodiment and advantage thereof, be to be understood that under the situation of the protection range that the spirit that does not break away from the utility model and accompanying claims limit, can carry out various variations, replacement and modification to these embodiment.For other examples, when those of ordinary skill in the art should understand easily in keeping the utility model protection range, the order of processing step can change.

In addition, the range of application of the utility model is not limited to technology, mechanism, manufacturing, material composition, means, scheme and the step of the specific embodiment of describing in the specification.Disclosure from the utility model; To easily understand as those of ordinary skill in the art; For the technology, mechanism, manufacturing, material composition, means, scheme or the step that have existed or be about to later on develop at present; Wherein they are carried out the corresponding embodiment cardinal principle identical functions of describing with the utility model or obtain identical substantially result, can use them according to the utility model.

Therefore, the utility model accompanying claims is intended to these technology, mechanism, manufacturing, material composition, means, scheme or step are included in its protection range.Should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the utility model principle, can also make some improvement and retouching, these improvement and retouching also should be regarded as the protection range of the utility model.

Claims (7)

1. the startup of a low-power consumption and under-voltage protecting circuit device is characterized in that, comprise the status latch that starting resistor detection module and voltage are sluggish,

Said starting resistor detection module is used for the supply power voltage of detection chip, when said supply power voltage is higher than the upper voltage limit threshold value, and Enable Pin output enable signal, the PWM control module of opening chip allows the chip operate as normal; When supply power voltage was lower than the lower voltage limit threshold value, enable signal was closed the PWM control module of chip;

The status latch that voltage is sluggish when supply power voltage is lower than the lower voltage limit threshold value, when enable signal is closed the PWM control module of chip, forms the sluggish relation of voltage, realizes the function of chip under-voltage protection.

2. the startup of low-power consumption as claimed in claim 1 and under-voltage protecting circuit device is characterized in that, said starting resistor detection module is realized voltage detecting through comparable chip supply power voltage and chip internal benchmark.

3. the startup of low-power consumption as claimed in claim 1 and under-voltage protecting circuit device is characterized in that, the sluggish status latch of said voltage comprises at least two inverters.

4. a Switching Power Supply is characterized in that, comprises the startup and the under-voltage protecting circuit device of low-power consumption, the PWM controller,

The startup of said low-power consumption and under-voltage protecting circuit device; Be used for according to the said PWM controller of supply power voltage output enable signal controlling; Wherein, when said supply power voltage was higher than the upper voltage limit threshold value, the PWM control module of output enable unblanking chip allowed the chip operate as normal; When supply power voltage was lower than the lower voltage limit threshold value, enable signal was closed the PWM control module of chip, and Switching Power Supply is in the under-voltage protection state simultaneously;

Said PWM controller is used to receive the startup of said low-power consumption and the enable signal and the pwm control signal input of under-voltage protecting circuit device output, and the output signal is realized the switch of power supply.

5. Switching Power Supply as claimed in claim 4 is characterized in that, the startup of said low-power consumption and under-voltage protecting circuit device comprise starting resistor detection module and the sluggish status latch of voltage,

Said starting resistor detection module is used for the supply power voltage of detection chip, when said supply power voltage is higher than the upper voltage limit threshold value, and Enable Pin output enable signal, the PWM control module of opening chip allows the chip operate as normal; When supply power voltage was lower than the lower voltage limit threshold value, enable signal was closed the PWM control module of chip;

The status latch that voltage is sluggish when supply power voltage is lower than the lower voltage limit threshold value, when enable signal is closed the PWM control module of chip, forms sluggish voltage relationship, realizes the function of chip under-voltage protection.

6. Switching Power Supply as claimed in claim 5 is characterized in that, said starting resistor detection module is realized voltage detecting through comparable chip supply power voltage and chip internal benchmark.

7. Switching Power Supply as claimed in claim 5 is characterized in that, the sluggish status latch of said voltage comprises at least two inverters.

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