CN105048422A - Switch transistor voltage drop holding circuit and application of switch transistor voltage drop holding circuit in lithium battery protection circuit - Google Patents
Switch transistor voltage drop holding circuit and application of switch transistor voltage drop holding circuit in lithium battery protection circuit Download PDFInfo
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- CN105048422A CN105048422A CN201510557034.5A CN201510557034A CN105048422A CN 105048422 A CN105048422 A CN 105048422A CN 201510557034 A CN201510557034 A CN 201510557034A CN 105048422 A CN105048422 A CN 105048422A
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- 229910052744 lithium Inorganic materials 0.000 title claims abstract description 28
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims abstract description 22
- 230000005669 field effect Effects 0.000 claims abstract description 172
- 150000002641 lithium Chemical class 0.000 claims description 6
- 230000001681 protective effect Effects 0.000 description 12
- 230000005611 electricity Effects 0.000 description 7
- 229910001416 lithium ion Inorganic materials 0.000 description 6
- 238000010586 diagram Methods 0.000 description 4
- 230000005059 dormancy Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
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- Charge And Discharge Circuits For Batteries Or The Like (AREA)
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Abstract
The invention provides a switch transistor voltage drop holding circuit comprising a first field effect transistor. The switch transistor voltage drop holding circuit is characterized in that the first input end of the voltage drop holding circuit is connected with the drain electrode of the first field effect transistor, the second input end is connected with the driving signal of the first field effect transistor, the output end is connected with the gate electrode of the first field effect transistor, and the source electrode of the first field effect transistor is grounded. When the second input end is low-level "0", the output end of the voltage drop holding circuit is low-level "0" constantly. When voltage of the first input end and the ground is greater than reference voltage and the second input end is high-level "1", the output end of the voltage drop holding circuit is high-level "1". When voltage of the first input end and the ground is less than reference voltage and the second input end is high-level "1", the output end of the voltage drop holding circuit is low-level "0". Advantages of the switch transistor voltage drop holding circuit are that the circuit structure is simple, and the first field effect transistor is enabled to possess the set voltage drop value constantly under the condition of extremely low load current so that normal conduction and work of the whole lithium battery protection control circuit can be guaranteed.
Description
Technical field
The present invention relates to a kind of pressure drop holding circuit, particularly a kind of switch transistors tube voltage drop holding circuit and the application in lithium battery charge and discharge protective circuit thereof.
Background technology
Lithium battery in use; overcharge, useful life and performance that over-discharge can or overload current all can have influence on battery; in order to use safety is considered; the battery core design of lithium battery must install protective circuit additional, preventing because overcharging, crossing and putting or short circuit and the danger such as cells burst, blast that causes.In actual use, the power consumption when non-loaded of the claimed circuit of people is more few better, preferably not power consumption.
As shown in Figure 6, for the line assumption diagram of lithium battery charge and discharge protective circuit that can realize at present, this protective circuit is (such as several amperes to hundreds of ampere) when load current is constant or load current is larger, as long as be usually connected in series the sample resistance (not shown) that has setting resistance in load circuit, when load RL connects, load current produces pressure drop by sample resistance, the grid of the first switching tube Q01 (N channel field-effect pipe) obtains forward voltage conducting, make second switch pipe Q02 (P-channel field-effect transistor (PEFT) pipe) also conducting, li-ion cell protection control circuit energising work, simultaneously, li-ion cell protection control circuit output drive signal iQ1, whole li-ion cell protection control circuit obtains the normal work of electricity,
When load RL disconnects, load current is the grid no-voltage of the zero, first switching tube Q01; first switching tube cut-off, so second switch pipe Q02 also ends; the power-off of li-ion cell protection control circuit, namely battery is under no-load condition, the not power consumption substantially of whole protective circuit.
But; in real work; load current can change within the scope of several milliampere, even several microamperes from kilo-ampere, and the electricity that obtains smoothly only adopting the sampling resistor (sample resistance is only several milliohm under normal circumstances) of a fixed value cannot realize protective circuit in the load current value situation of all changes works.As shown in Figure 6, when protective circuit (only has several milliampere or several microampere) when load current is extremely little, the now pressure drop at transistor Q1 two ends is zero substantially, the grid potential of the first switching tube Q01 cannot reach its cut-in voltage value (cut-in voltage of usual first switching tube zero point a few volt to three ten-day period of hot season scope), after the first switching tube Q01 ends, second switch pipe Q02 also ends, thus causes li-ion cell protection control circuit cannot obtain electricity work; If sample resistance is selected ensure that more greatly the conducting of circuit is (in order to reduce circuit power consumption; usual sample resistance is not too large); then whole circuit can produce larger power consumption because of the existence of large resistance, and this design concept the smaller the better with the requirement power consumption of lithium battery protection circuit is again runed counter to.
Therefore; how when load current is very little; ensure the normal work of circuit, can be problem demanding prompt solution in current lithium battery charge and discharge protective circuit design in the power consumption of large load current situation decline low circuit again, need to make further improvement to existing scheme.
Summary of the invention
First technical problem to be solved by this invention provides for above-mentioned prior art present situation a kind of structure simple and can maintain the switch transistors tube voltage drop holding circuit that transistor two ends have setting voltage drop value all the time under minor load electric current.
Second technical problem to be solved by this invention provides a kind of low-power consumption lithium battery charge and discharge protective circuit adopting above-mentioned switch transistors tube voltage drop holding circuit for above-mentioned prior art present situation.
The present invention solves the technical scheme that above-mentioned first technical problem adopt: a kind of switch transistors tube voltage drop holding circuit, include N raceway groove first field effect transistor, drain electrode and the source electrode of described first field effect transistor are serially connected on load circuit, it is characterized in that: described pressure drop holding circuit is set with a reference voltage, this pressure drop holding circuit includes first input end, second input, output and ground, wherein, the first input end of described pressure drop holding circuit connects the drain electrode of described first field effect transistor, second input of described pressure drop holding circuit is connected with the drive singal of described first field effect transistor, the output of described pressure drop holding circuit connects the grid of described first field effect transistor, the direct ground connection of earth terminal of described pressure drop holding circuit, further, between the input of described pressure drop holding circuit and output, there is following logical relation:
Voltage between described first input end and earth terminal is greater than described reference voltage, and when the second input is low level " 0 ", the output of described pressure drop holding circuit is low level " 0 ";
Voltage between described first input end and earth terminal is less than described reference voltage, and when the second input is low level " 0 ", the output of described pressure drop holding circuit is low level " 0 ";
Voltage between described first input end and earth terminal is greater than described reference voltage, and when the second input is high level " 1 ", the output of described pressure drop holding circuit is high level " 1 ";
Voltage between described first input end and earth terminal is less than described reference voltage, and when the second input is high level " 1 ", the output of described pressure drop holding circuit is low level " 0 ".
As preferably, described pressure drop holding circuit can be specially: include N raceway groove second field effect transistor and the second comparator, wherein, the negative input of described second comparator is connected with the drain electrode of described first field effect transistor, electrode input end ground connection after the second reference voltage of described second comparator, the source ground of described first field effect transistor; The output of described second comparator is connected with the grid of described second field effect transistor, drain electrode one tunnel of this second field effect transistor is connected with the grid of described first field effect transistor, another road is connected with the drive singal of described first field effect transistor, the source ground of described second field effect transistor.
Preferred as another, described pressure drop holding circuit also can be specially: include P raceway groove the 3rd field effect transistor and the 3rd comparator, wherein, the negative input of described 3rd comparator is connected with the drain electrode of described first field effect transistor, electrode input end ground connection after the 3rd reference voltage of described 3rd comparator, the source ground of described first field effect transistor; The output of described 3rd comparator is connected with the grid of described 3rd field effect transistor, and the source electrode of the 3rd field effect transistor is connected with the drive singal of described first field effect transistor, and the drain electrode of the 3rd field effect transistor is connected with the grid of described first field effect transistor.
The present invention solves the technical scheme that above-mentioned second technical problem adopt: this lithium battery protection circuit includes protecting control circuit, battery, N raceway groove first switching tube, the P raceway groove second switch pipe that can control described protecting control circuit power break-make, the first comparator, the second comparator, N raceway groove first field effect transistor, N raceway groove second field effect transistor, resistance and electric capacity, and this protecting control circuit has the trigger output end of exportable drive singal; Wherein, the grid of described first switching tube is connected with the drain electrode of described first field effect transistor, and the drain electrode of this first switching tube is connected with the grid of described second switch pipe, the source ground of this first switching tube; Negative input one tunnel of described first comparator is connected with the drain electrode of described first field effect transistor, and another road connects one end of load; The other end one tunnel of described load is through described battery ground, and another road connects the source electrode of described second switch pipe; Electrode input end ground connection after the first reference voltage of described first comparator; Output road after described resistance of described first comparator connects the grid of described second switch pipe, and another road is through described capacity earth; Drain electrode ground connection after described protecting control circuit of described second switch pipe; The negative input of described second comparator is connected with the drain electrode of described first field effect transistor, electrode input end ground connection after the second reference voltage of described second comparator, the source ground of described first field effect transistor; The output of described second comparator is connected with the grid of described second field effect transistor, and drain electrode one tunnel of this second field effect transistor is connected with the grid of described first field effect transistor, and another road is connected with the trigger output end of described protecting control circuit; The source ground of described second field effect transistor; Further, the pressure drop of described first reference voltage is less than the pressure drop of the second reference voltage.
Preferred as another, this lithium battery protection circuit includes protecting control circuit, battery, N raceway groove first switching tube, the P raceway groove second switch pipe that can control described protecting control circuit power break-make, the first comparator, the 3rd comparator, N raceway groove first field effect transistor, P raceway groove the 3rd field effect transistor, resistance and electric capacity, and this protecting control circuit has the trigger output end of exportable drive singal; Wherein, the grid of described first switching tube is connected with the drain electrode of described first field effect transistor, and the drain electrode of this first switching tube is connected with the grid of described second switch pipe, the source ground of this first switching tube; Negative input one tunnel of described first comparator is connected with the drain electrode of described first field effect transistor, and another road connects one end of load; The other end one tunnel of described load is through described battery ground, and another road connects the source electrode of described second switch pipe; Electrode input end ground connection after the first reference voltage of described first comparator; Output road after described resistance of described first comparator connects the grid of described second switch pipe, and another road is through described capacity earth; Drain electrode ground connection after described protecting control circuit of described second switch pipe; The negative input of described 3rd comparator is connected with the drain electrode of described first field effect transistor, electrode input end ground connection after the 3rd reference voltage of described 3rd comparator, the source ground of described first field effect transistor; The output of described 3rd comparator is connected with the grid of described 3rd field effect transistor, and the source electrode of the 3rd field effect transistor is connected with the trigger output end of described protecting control circuit, and the drain electrode of the 3rd field effect transistor is connected with the grid of described first field effect transistor; Further, the pressure drop of described first reference voltage is less than the pressure drop of the 3rd reference voltage.
The second field effect transistor in above-mentioned two lithium battery protection circuits and the 3rd field effect transistor can replace to triode respectively, and correspondingly, the grid of field effect transistor, source electrode and drain electrode are substituted by the base stage of corresponding triode, emitter and collector respectively.
Compared with prior art; the invention has the advantages that: the present invention design pressure drop holding circuit input, there is between output and reference voltage certain logical relation; this pressure drop holding circuit structure is simple; whole circuit is realized by comparator and switching transistor; can when load current be extremely small; ensure to be serially connected in the voltage drop value the first field effect transistor in load circuit all the time with setting, and then ensure the normal power-up work of whole li-ion cell protection control circuit.
Accompanying drawing explanation
Fig. 1 is the theory diagram of switch transistors tube voltage drop holding circuit of the present invention.
Fig. 2 is one of concrete line map of switch transistors tube voltage drop holding circuit of the present invention.
Fig. 3 is the application of pressure drop holding circuit in lithium battery charge and discharge protective circuit shown in Fig. 2.
Fig. 4 is the concrete line map two of switch transistors tube voltage drop holding circuit of the present invention.
Fig. 5 is the application of pressure drop holding circuit in lithium battery charge and discharge protective circuit shown in Fig. 4.
Fig. 6 is the line assumption diagram of lithium battery charge and discharge protective circuit of the prior art.
Embodiment
Below in conjunction with accompanying drawing embodiment, the present invention is described in further detail.
As shown in Figure 1, be switch transistors tube voltage drop holding circuit schematic diagram of the present invention, switch transistors tube voltage drop holding circuit T1 when load current is very little, can ensure that the switching transistor be serially connected on load circuit can maintain the voltage drop value of setting all the time.
Switch transistors tube voltage drop holding circuit T1 of the present invention includes N raceway groove first field effect transistor Q1, the drain electrode of the first field effect transistor Q1 and source electrode are serially connected on load circuit, a reference voltage is set with in pressure drop holding circuit T1, this pressure drop holding circuit T1 includes first input end A, second input B, output D and earth terminal G, wherein, the first input end A of pressure drop holding circuit T1 connects the drain electrode of the first field effect transistor Q1, the second input B of pressure drop holding circuit T1 is connected with the drive singal iQ1 of the first field effect transistor Q1, the output D of pressure drop holding circuit T1 connects the grid of the first field effect transistor Q1, the direct ground connection of earth terminal G of pressure drop holding circuit T1, source electrode (usually after a sample resistance) ground connection of the first field effect transistor Q1, further, between the input of pressure drop holding circuit T1 and output, there is following logical relation:
When the voltage of first input end A and earth terminal G is greater than reference voltage, and when the second input B is low level " 0 ", the output D of pressure drop holding circuit is low level " 0 ";
When the voltage of first input end A and earth terminal G is less than reference voltage, and when the second input B is low level " 0 ", the output D of pressure drop holding circuit is low level " 0 ";
When the voltage of first input end A and earth terminal G is greater than reference voltage, and when the second input B is high level " 1 ", the output D of pressure drop holding circuit is high level " 1 ";
When the voltage of first input end A and earth terminal G is less than reference voltage, and when the second input B is high level " 1 ", the output D of pressure drop holding circuit is low level " 0 ".
When the second input B is low level, whether the voltage no matter between first input end A and earth terminal G is greater than the reference voltage of inner setting, then the output D of this pressure drop holding circuit T1 exports all the time as low level, and the first field effect transistor Q1 by; Only have when the second input B is high level, in the reference voltage situation that the voltage of first input end A and earth terminal G is less than inner setting, the output D of pressure drop holding circuit is transformed to low level " 0 " by high level " 1 ", thus the drain potential of the first field effect transistor Q1 is raised, ensure the voltage drop value that can maintain setting between the drain electrode of the first field effect transistor Q1 and source electrode.
Embodiment one, as shown in Figure 2 and Figure 3:
The switch transistors tube voltage drop holding circuit T1 of the present embodiment one is specially: include N raceway groove second field effect transistor Q2 and the second comparator BG2, wherein, the negative input of the second comparator BG2 is connected with the drain electrode of the first field effect transistor Q1, electrode input end ground connection after the second reference voltage E2 of the second comparator BG2, the source ground of the first field effect transistor Q1; The output of the second comparator BG2 is connected with the grid of the second field effect transistor Q2, drain electrode one tunnel of this second field effect transistor Q2 is connected with the grid of the first field effect transistor Q1, another road is connected with the drive singal iQ1 of the first field effect transistor Q1, the source ground of the second field effect transistor Q2.
Fig. 3 is the embody rule of switch transistors tube voltage drop holding circuit T1 in lithium battery protection circuit of the present embodiment one, this lithium battery protection circuit includes protecting control circuit, battery DC, N raceway groove first switching tube Q01 (also can be NPN type triode), the P raceway groove second switch pipe Q02 (also can be PNP type triode) of protecting control circuit power break-make can be controlled, be set with the first comparator BG1 of the first reference voltage E1, be set with the second comparator BG2 of the second reference voltage E2, N raceway groove second field effect transistor Q2, resistance R and electric capacity C, this protecting control circuit has the trigger output end of exportable drive singal iQ1, and, first reference voltage E1 is less than the second reference voltage E2,
Wherein, the grid of the first switching tube Q01 is connected with the drain electrode of the first field effect transistor Q1, and the drain electrode of this first switching tube Q01 is connected with the grid of second switch pipe Q02, the source ground of this first switching tube Q01; Negative input one tunnel of the first comparator BG1 is connected with the drain electrode of the first field effect transistor Q1, and another road connects one end of load RL; The other end one tunnel of load RL is through battery DC ground connection, and another road connects the source electrode of second switch pipe Q02; Electrode input end ground connection after the first reference voltage of the first comparator BG1; Output road after resistance R of the first comparator BG1 connects the grid of second switch pipe Q02, and another road is through electric capacity C ground connection; Drain electrode ground connection after protecting control circuit of second switch pipe Q02; The negative input of the second comparator BG2 is connected with the drain electrode of the first field effect transistor Q1, electrode input end ground connection after the second reference voltage of the second comparator BG2, the source ground of the first field effect transistor Q1; The output of the second comparator BG2 is connected with the grid of the second field effect transistor Q2, and drain electrode one tunnel of this second field effect transistor Q2 is connected with the grid of the first field effect transistor Q1, and another road is connected with the trigger output end of protecting control circuit; The source ground of the second field effect transistor Q2.
Field effect transistor in above-described embodiment one all can replace with triode, and correspondingly, the grid of field effect transistor, source electrode and drain electrode are substituted by the base stage of corresponding triode, emitter and collector respectively.
The lithium battery protection circuit operation principle of embodiment one is: when load RL connects moment; protecting control circuit is in " dormancy " state; export without drive singal iQ1; first field effect transistor Q1 is in cut-off state; voltage between its drain electrode and source electrode is close to the supply power voltage into battery DC; the grid of the first switching tube Q01 obtains forward voltage and conducting, second switch pipe Q02 conducting thereupon.
So protecting control circuit and the first comparator BG1, the second comparator BG2 all obtain electricity work, meanwhile, protecting control circuit output drive signal iQ1; If now drive singal iQ1 is high level and load current is greater than the first reference voltage E1 (the first reference voltage E1 can be set as that millivolt level is even lower) in the upper pressure drop produced of the first field effect transistor Q1 internal resistance (and sample resistance); then the first comparator BG1 output low level; second switch pipe Q02 will be in conducting state all the time, and protecting control circuit normally obtains electricity work.
If load current very little (only having several milliamperes of even several microamperes), during cause the pressure drop between the drain electrode of the first field effect transistor Q1 and ground to be less than the second reference voltage E2 that pressure drop holding circuit T1 sets, voltage then between the negative input of the second comparator BG2 and ground is less than the electrode input end voltage of this second comparator BG2, second comparator BG2 exports high level, second field effect transistor Q2 conducting, the grid potential of the first field effect transistor Q1 is dragged down, so the drain potential of the first field effect transistor Q1 raises; When the drain potential of the first field effect transistor Q1 rise to be greater than the second reference voltage E2 time, the second comparator BG2 output low level, the second field effect transistor Q2 cut-off, the first field effect transistor Q1 is under the effect of drive singal iQ1, and drain potential reduces.
Circulation like this, can remain on the voltage drop value (i.e. the second reference voltage E2) of setting by the pressure drop over the ground of the first field effect transistor Q1; Because the first reference voltage E1 of setting is less than the second reference voltage E2; therefore; the current potential of the negative input of the first comparator BG1 is all the time higher than the current potential of electrode input end; namely the output of the first comparator BG1 is always low level; then second switch pipe Q02 is in conducting state all the time; ensure that protecting control circuit is when load current size changes arbitrarily, can obtain the reliable power supply of battery DC.
Under load RL disconnection; load current is zero; pressure drop between the drain electrode of the first field effect transistor Q1 and ground is zero; first switching tube Q01 ends, and the first comparator BG1 exports high level, and second switch pipe Q02 ends; protecting control circuit and the first comparator BG1, the equal power-off of the second comparator BG2; first field effect transistor Q1 cut-off, so, the not power consumption of whole protecting control circuit " dormancy ".
Embodiment two, as shown in Figure 4, Figure 5:
The pressure drop holding circuit T1 of the present embodiment two is specially: include P raceway groove the 3rd field effect transistor Q3 and the 3rd comparator BG3, wherein, the negative input of the 3rd comparator BG3 is connected with the drain electrode of the first field effect transistor Q1, electrode input end ground connection after the 3rd reference voltage E3 of the 3rd comparator BG3, the source ground of the first field effect transistor Q1; The output of the 3rd comparator BG3 is connected with the grid of the 3rd field effect transistor Q3, and the source electrode of the 3rd field effect transistor Q3 is connected with the drive singal iQ1 of the first field effect transistor Q1, and the drain electrode of the 3rd field effect transistor Q3 is connected with the grid of the first field effect transistor Q1.
Fig. 5 is the application of switch transistors tube voltage drop holding circuit T1 in lithium battery protection circuit of the present embodiment two, this lithium battery protection circuit includes protecting control circuit, battery DC, N raceway groove first switching tube Q01 (also can be NPN type triode), the P raceway groove second switch pipe Q02 (also can be PNP type triode) of protecting control circuit power break-make can be controlled, be set with the first comparator BG1 of the first reference voltage E1, be set with the 3rd comparator BG3 of the 3rd reference voltage E3, P raceway groove the 3rd field effect transistor Q3, resistance R and electric capacity C, this protecting control circuit has the trigger output end of output drive signal iQ1,
Wherein, the grid of the first switching tube Q01 is connected with the drain electrode of the first field effect transistor Q1, and the drain electrode of this first switching tube Q01 is connected with the grid of second switch pipe Q02, the source ground of this first switching tube Q01; Negative input one tunnel of the first comparator BG1 is connected with the drain electrode of the first field effect transistor Q1, and another road connects one end of load RL; The other end one tunnel of load RL is through battery DC ground connection, and another road connects the source electrode of second switch pipe Q02; Electrode input end ground connection after the first reference voltage of the first comparator BG1; Output road after resistance R of the first comparator BG1 connects the grid of second switch pipe Q02, and another road is through electric capacity C ground connection; Drain electrode ground connection after protecting control circuit of second switch pipe Q02; The negative input of the 3rd comparator BG3 is connected with the drain electrode of the first field effect transistor Q1, electrode input end ground connection after the 3rd reference voltage E3 of the 3rd comparator BG3, the source ground of the first field effect transistor Q1; The output of the 3rd comparator BG3 is connected with the grid of the 3rd field effect transistor Q3, and the source electrode of the 3rd field effect transistor Q3 is connected with the trigger output end of protecting control circuit, and the drain electrode of the 3rd field effect transistor Q3 is connected with the grid of the first field effect transistor Q1.
Field effect transistor in above-described embodiment two all can replace with triode, and correspondingly, the grid of field effect transistor, source electrode and drain electrode are substituted by the base stage of corresponding triode, emitter and collector respectively.
The lithium battery protection circuit operation principle of embodiment two is: when load RL connects moment; protecting control circuit is in " dormancy " state; export without drive singal iQ1; first field effect transistor Q1 is in cut-off state; voltage between its drain electrode and source electrode is close to the supply power voltage into battery DC; the grid of the first switching tube Q01 obtains forward voltage and conducting, second switch pipe Q02 conducting thereupon.
So, protecting control circuit and the first comparator BG1, the 3rd comparator BG3 all obtain electricity work, now, if load current is enough large, voltage between the negative input of the 3rd comparator BG3 and ground is greater than the 3rd comparator BG3 electrode input end voltage, the 3rd comparator BG3 output low level, the 3rd field effect transistor Q3 conducting, meanwhile, protecting control circuit output drive signal iQ1; If now drive iQ1 to be high level and load current is greater than the first reference voltage E1 (the first reference voltage E1 can be set as that millivolt level is even lower) in the upper pressure drop produced of the first field effect transistor Q1 internal resistance (and sample resistance); then the first comparator BG1 output low level; second switch pipe Q02 will be in conducting state all the time, and protecting control circuit normally obtains electricity work.
If load current very little (only having several milliamperes of even several microamperes), during cause the pressure drop between the drain electrode of the first field effect transistor Q1 and ground to be less than the 3rd reference voltage E3 that pressure drop holding circuit T1 sets, voltage then between the negative input of the 3rd comparator BG3 and ground is less than the electrode input end voltage of the 3rd comparator BG3, 3rd comparator BG3 exports high level, 3rd field effect transistor Q3 cut-off (i.e. between the grid of drive singal iQ1 and the first field effect transistor Q1, circuit disconnects), the grid potential of the first field effect transistor Q1 is dragged down, so, the drain potential of the first field effect transistor Q1 raises, when the drain potential of the first field effect transistor Q1 rise to be greater than the 3rd reference voltage E3 time, the 3rd comparator BG3 output low level, the 3rd field effect transistor Q3 conducting again, the first field effect transistor Q1 is under the effect of drive singal iQ1, and drain potential reduces.
Circulation like this, can remain on the voltage drop value (i.e. the 3rd reference voltage E3) of setting by the pressure drop over the ground of the first field effect transistor Q1; Because the first reference voltage E1 of setting is less than the 3rd reference voltage E3; therefore; the current potential of the negative input of the first comparator BG1 is all the time higher than the current potential of electrode input end; namely the output of the first comparator BG1 is always low level; then second switch pipe Q02 is in conducting state all the time; ensure that protecting control circuit is when load current size changes arbitrarily, can obtain the reliable power supply of battery DC.
Under load RL disconnection; load current is zero; pressure drop between the drain electrode of the first field effect transistor Q1 and ground is zero; first switching tube Q01 ends, and the first comparator BG1 exports high level, and second switch pipe Q02 ends; protecting control circuit and the first comparator BG1, the equal power-off of the 3rd comparator BG3; first field effect transistor Q1 cut-off, so, the not power consumption of whole protecting control circuit " dormancy ".
Claims (7)
1. a switch transistors tube voltage drop holding circuit, include N raceway groove first field effect transistor, drain electrode and the source electrode of described first field effect transistor are serially connected on load circuit, it is characterized in that: described pressure drop holding circuit is set with a reference voltage, this pressure drop holding circuit includes first input end, second input, output and ground, wherein, the first input end of described pressure drop holding circuit connects the drain electrode of described first field effect transistor, second input of described pressure drop holding circuit is connected with the drive singal of described first field effect transistor, the output of described pressure drop holding circuit connects the grid of described first field effect transistor, the source ground of described first field effect transistor, the direct ground connection of earth terminal of described pressure drop holding circuit, further, between the input of described pressure drop holding circuit and output, there is following logical relation:
Voltage between described first input end and earth terminal is greater than described reference voltage, and when the second input is low level " 0 ", the output of described pressure drop holding circuit is low level " 0 ";
Voltage between described first input end and earth terminal is less than described reference voltage, and when the second input is low level " 0 ", the output of described pressure drop holding circuit is low level " 0 ";
Voltage between described first input end and earth terminal is greater than described reference voltage, and when the second input is high level " 1 ", the output of described pressure drop holding circuit is high level " 1 ";
Voltage between described first input end and earth terminal is less than described reference voltage, and when the second input is high level " 1 ", the output of described pressure drop holding circuit is low level " 0 ".
2. switch transistors tube voltage drop holding circuit according to claim 1, it is characterized in that: described pressure drop holding circuit is specially: include N raceway groove second field effect transistor and the second comparator, wherein, the negative input of described second comparator is connected with the drain electrode of described first field effect transistor, electrode input end ground connection after the second reference voltage of described second comparator, the source ground of described first field effect transistor; The output of described second comparator is connected with the grid of described second field effect transistor, drain electrode one tunnel of this second field effect transistor is connected with the grid of described first field effect transistor, another road is connected with the drive singal of described first field effect transistor, the source ground of described second field effect transistor.
3. switch transistors tube voltage drop holding circuit according to claim 1, it is characterized in that: described pressure drop holding circuit is specially: include P raceway groove the 3rd field effect transistor and the 3rd comparator, wherein, the negative input of described 3rd comparator is connected with the drain electrode of described first field effect transistor, electrode input end ground connection after the 3rd reference voltage of described 3rd comparator, the source ground of described first field effect transistor; The output of described 3rd comparator is connected with the grid of described 3rd field effect transistor, and the source electrode of the 3rd field effect transistor is connected with the drive singal of described first field effect transistor, and the drain electrode of the 3rd field effect transistor is connected with the grid of described first field effect transistor.
4. a lithium battery protection circuit, it is characterized in that: this lithium battery protection circuit includes protecting control circuit, battery, N raceway groove first switching tube, the P raceway groove second switch pipe that can control described protecting control circuit power break-make, the first comparator, the second comparator, N raceway groove first field effect transistor, N raceway groove second field effect transistor, resistance and electric capacity, and this protecting control circuit has the trigger output end of exportable drive singal;
Wherein, the grid of described first switching tube is connected with the drain electrode of described first field effect transistor, and the drain electrode of this first switching tube is connected with the grid of described second switch pipe, the source ground of this first switching tube; Negative input one tunnel of described first comparator is connected with the drain electrode of described first field effect transistor, and another road connects one end of load; The other end one tunnel of described load is through described battery ground, and another road connects the source electrode of described second switch pipe; Electrode input end ground connection after the first reference voltage of described first comparator; Output road after described resistance of described first comparator connects the grid of described second switch pipe, and another road is through described capacity earth; Drain electrode ground connection after described protecting control circuit of described second switch pipe; The negative input of described second comparator is connected with the drain electrode of described first field effect transistor, electrode input end ground connection after the second reference voltage of described second comparator, the source ground of described first field effect transistor; The output of described second comparator is connected with the grid of described second field effect transistor, and drain electrode one tunnel of this second field effect transistor is connected with the grid of described first field effect transistor, and another road is connected with the trigger output end of described protecting control circuit; The source ground of described second field effect transistor; Further, the pressure drop of described first reference voltage is less than the pressure drop of the second reference voltage.
5. lithium battery protection circuit according to claim 4; it is characterized in that: the second described field effect transistor is triode; correspondingly, the grid of described second field effect transistor, source electrode and drain electrode are substituted by the base stage of described triode, emitter and collector respectively.
6. a lithium battery protection circuit, it is characterized in that: this lithium battery protection circuit includes protecting control circuit, battery, N raceway groove first switching tube, the P raceway groove second switch pipe that can control described protecting control circuit power break-make, the first comparator, the 3rd comparator, N raceway groove first field effect transistor, P raceway groove the 3rd field effect transistor, resistance and electric capacity, and this protecting control circuit has the trigger output end of exportable drive singal;
Wherein, the grid of described first switching tube is connected with the drain electrode of described first field effect transistor, and the drain electrode of this first switching tube is connected with the grid of described second switch pipe, the source ground of this first switching tube; Negative input one tunnel of described first comparator is connected with the drain electrode of described first field effect transistor, and another road connects one end of load; The other end one tunnel of described load is through described battery ground, and another road connects the source electrode of described second switch pipe; Electrode input end ground connection after the first reference voltage of described first comparator; Output road after described resistance of described first comparator connects the grid of described second switch pipe, and another road is through described capacity earth; Drain electrode ground connection after described protecting control circuit of described second switch pipe; The negative input of described 3rd comparator is connected with the drain electrode of described first field effect transistor, electrode input end ground connection after the 3rd reference voltage of described 3rd comparator, the source ground of described first field effect transistor; The output of described 3rd comparator is connected with the grid of described 3rd field effect transistor, and the source electrode of the 3rd field effect transistor is connected with the trigger output end of described protecting control circuit, and the drain electrode of the 3rd field effect transistor is connected with the grid of described first field effect transistor; Further, the pressure drop of described first reference voltage is less than the pressure drop of the 3rd reference voltage.
7. lithium battery protection circuit according to claim 6; it is characterized in that: the 3rd described field effect transistor is triode; correspondingly, the grid of described 3rd field effect transistor, source electrode and drain electrode are substituted by the base stage of described triode, emitter and collector respectively.
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| CN201510557034.5A CN105048422B (en) | 2015-09-02 | 2015-09-02 | Switching transistor pressure drop holding circuit and application have the lithium battery protection circuit of the pressure drop holding circuit |
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| CN201510557034.5A CN105048422B (en) | 2015-09-02 | 2015-09-02 | Switching transistor pressure drop holding circuit and application have the lithium battery protection circuit of the pressure drop holding circuit |
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| CN105048422B CN105048422B (en) | 2018-05-08 |
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Cited By (7)
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| CN107846214A (en) * | 2016-09-19 | 2018-03-27 | 格芯公司 | Integrated level translator and latch for fence framework |
| CN108327876A (en) * | 2018-02-22 | 2018-07-27 | 陈蜀乔 | There is the magnetic current propulsion system for pushing away water groove in a kind of submariner device outer surface |
| CN109245507A (en) * | 2018-11-08 | 2019-01-18 | 上海艾为电子技术股份有限公司 | A kind of anti-overshoot protection circuit |
| CN110011378A (en) * | 2019-04-19 | 2019-07-12 | 深圳市山河动力电子有限公司 | A lithium battery protection board overcurrent detection protection circuit |
| CN111342647A (en) * | 2020-03-30 | 2020-06-26 | 西安电子科技大学 | Current-limiting protection method and circuit for high-side power switch |
| CN113472296A (en) * | 2021-08-05 | 2021-10-01 | 东莞凯韵科技有限公司 | Switching circuit and control method of electron tube and transistor |
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107846214A (en) * | 2016-09-19 | 2018-03-27 | 格芯公司 | Integrated level translator and latch for fence framework |
| CN107846214B (en) * | 2016-09-19 | 2022-04-12 | 马维尔亚洲私人有限公司 | Integrated level shifter and latch for fence architecture |
| CN108327876A (en) * | 2018-02-22 | 2018-07-27 | 陈蜀乔 | There is the magnetic current propulsion system for pushing away water groove in a kind of submariner device outer surface |
| CN109245507A (en) * | 2018-11-08 | 2019-01-18 | 上海艾为电子技术股份有限公司 | A kind of anti-overshoot protection circuit |
| CN109245507B (en) * | 2018-11-08 | 2024-02-09 | 上海艾为电子技术股份有限公司 | Overshoot-preventing protection circuit |
| CN113678335A (en) * | 2019-03-28 | 2021-11-19 | 昕诺飞控股有限公司 | Avalanche-triggered overvoltage protection |
| CN110011378A (en) * | 2019-04-19 | 2019-07-12 | 深圳市山河动力电子有限公司 | A lithium battery protection board overcurrent detection protection circuit |
| CN111342647A (en) * | 2020-03-30 | 2020-06-26 | 西安电子科技大学 | Current-limiting protection method and circuit for high-side power switch |
| CN113472296A (en) * | 2021-08-05 | 2021-10-01 | 东莞凯韵科技有限公司 | Switching circuit and control method of electron tube and transistor |
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