CN204515677U - A kind of low-power consumption DC voltage compares circuit - Google Patents
A kind of low-power consumption DC voltage compares circuit Download PDFInfo
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- CN204515677U CN204515677U CN201520157260.XU CN201520157260U CN204515677U CN 204515677 U CN204515677 U CN 204515677U CN 201520157260 U CN201520157260 U CN 201520157260U CN 204515677 U CN204515677 U CN 204515677U
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Abstract
The utility model provides a kind of low-power consumption DC voltage to compare circuit, comprise for input end and the output terminal for output detections voltage: the first resistance between input end and ground in sequential series and the 5th resistance, the node that the first resistance is connected with the 5th resistance is first node; The emitter of the first transistor is connected with power supply by the second resistance, and collector is by the 6th resistance eutral grounding, and base stage passes through the 9th resistance with power supply to being connected; The base stage of the first transistor is connected with first node; The collector of transistor seconds is connected with power supply by the 7th resistance, and base stage is connected with the collector of the first transistor by the 8th resistance, and emitter is by the 3rd resistance eutral grounding, and the 7th resistance is greater than the 3rd resistance; The collector of transistor seconds is connected with output terminal.Utilize low-power consumption DC voltage of the present utility model to compare circuit, change in voltage can be detected in time, improve security of system, power consumption own is lower simultaneously, and reaction velocity is fast.
Description
Technical field
The utility model relates to a kind of low-power consumption DC voltage and compares circuit.
Background technology
In common industry or civilian application circuit system, system master controller single-chip microcomputer is powered by a mu balanced circuit, usual use LDO circuit (low-dropout linear voltage-regulating circuit) or DCDC circuit (DC-DC transfer circuit) realize, its power supply be input as one higher, unstable input voltage VHH, is generally 9V, 12V or higher, output is a stable low voltage value VCC, is generally voltage 5V or 3.3V etc. that system single-chip microcomputer uses.
When system power supply end breaks down, during as grid power blackout, due to outer power voltage without, input voltage VHH can fall from normal voltage levvl, below the minimum input voltage dropping into mu balanced circuit requirement, the operating voltage of system also fails, and at this moment Circuits System has not just worked.If this power-off is unexpected; especially when Circuits System is applied in important work; such as gas density collection; or Valve controlling etc.; if system does not have well in advance to prepare when power-off occurs; the loss of sensitive data so just may be caused because of this unexpected power-off, or because not taking protection act to bring potential risk.
In fact, input voltage VHH from fall, complete failure is exported to mu balanced circuit, centre has for tens to time interval of hundreds of millisecond, and (this depends on the size of the electric capacity of voltage regulation that the input and output of mu balanced circuit use, and the normal output current of mu balanced circuit), if the microcontroller of system just can obtain early warning signal when input voltage VHH starts to fall, this tens to time of hundreds of millisecond before system voltage not yet drops to power-off, take protection act in time, by important data backup to can the nonvolatile memory of no write de-lay as in NVRAM or ferroelectric memory, just can prevent this system risk.
Utility model content
The utility model is intended to solve the problems of the technologies described above, and provides a kind of low-power consumption DC voltage to compare circuit, can drop into and respond fast lower than by during threshold voltage set by resistance, output alarm signal, thus the safety of the system of guarantee at input voltage VHH.
The utility model provides a kind of low-power consumption DC voltage to compare circuit, comprising the input end for inputting input voltage and the output terminal for output detections voltage, also comprising:
The first resistance between described input end and ground in sequential series and the 5th resistance, the node that described first resistance is connected with described 5th resistance is first node;
The first transistor, the emitter of described the first transistor is connected with power supply by the second resistance, and collector is by the 6th resistance eutral grounding, and base stage is connected with power supply by the 9th resistance;
The base stage of the first transistor is connected with first node;
Transistor seconds, the collector of described transistor seconds is connected with power supply by the 7th resistance, base stage is connected with the collector of described the first transistor by the 8th resistance, and emitter is by the 3rd resistance eutral grounding, and described 7th resistance is greater than described 3rd resistance;
The collector of described transistor seconds is connected with described output terminal.
Preferably, also comprise the 4th resistance, the base stage of described the first transistor is connected with described first node by described 4th resistance;
Concrete, the resistance of described first resistance sets according to compare threshold size.
Preferably, the resistance of described 7th resistance is 10K Ω, and the resistance of described 3rd resistance is 10 Ω.
Preferably, described the first transistor is PNP transistor, and described transistor seconds is NPN transistor.
Low-power consumption DC voltage of the present utility model is utilized to compare circuit; just early warning signal can be obtained when input voltage starts to fall; utilize this tens to the time of hundreds of millisecond before system cut-off; take protection act in time; improve security of system; power consumption own is lower simultaneously, and reaction velocity is fast.
Accompanying drawing explanation
Fig. 1 is the circuit structure diagram that low-power consumption DC voltage of the present utility model compares circuit;
Fig. 2 is the graph of a relation of input voltage and output detections voltage;
Fig. 3 is magnified partial view in Fig. 2.
Embodiment
Compare circuit below in conjunction with accompanying drawing to low-power consumption DC voltage of the present utility model to be described in detail.Fig. 1 is the circuit structure diagram that low-power consumption DC voltage of the present utility model compares circuit, as shown in the figure, the output terminal of this circuit is for inputting input voltage VHH, output terminal is used for output detections voltage V_DETECTION, first resistance R1 is for arranging the compare threshold V_GATE of this comparator circuit, by regulating the resistance of the first resistance R1, arrange compare threshold V_GATE, physical relationship is as shown in the table:
| R1(KΩ) | Compare threshold V_GATE (V) |
| 220 | 9.8 |
| 180 | 8.8 |
| 150 | 8 |
| 110 | 7 |
The relation of table 1 first resistance and compare threshold
First resistance R1 in sequential series and the 5th resistance R5 between input end and earth terminal, the node between the first resistance R1 and the 5th resistance R5 is as first node.
The emitter of the first PNP pipe Q2 is connected with power supply V1 by the second resistance R2, and collector is by the 6th resistance R6 ground connection, and base stage is connected with power supply V1 by the 9th resistance R9.
Base stage the 4th resistance R4 of the first PNP pipe Q2 is connected with first node simultaneously.
The collector of the 2nd NPN pipe Q7 is connected with power supply V1 by the 7th resistance R7, emitter is by the 3rd resistance R3 ground connection, base stage is connected with the collector of the first PNP pipe Q2 by the 8th resistance R8,7th resistance R7 resistance is much larger than the 3rd resistance R3 resistance, the node that the collector of the 2nd NPN pipe Q7 is connected with the 7th resistance as output terminal, for output detections signal V_DETECTION.
In present embodiment, supply voltage V1 is 5V, the resistance of the 4th resistance R4 is 100 Ω, and the resistance of the 5th resistance R5 is 120K Ω, and the second resistance R2 resistance is 0 Ω, the resistance of the 6th resistance R6 is 10K Ω, the resistance of the 8th resistance R8 is 2K Ω, and the resistance of the 7th resistance R7 is 10K Ω, and the resistance of the 3rd resistance R3 is 10 Ω, first PNP pipe selects model to be 2N2907 transistor, and the 2nd NPN pipe selects model to be 2N2222 transistor.
In present embodiment, arranging compare threshold V_GATE is 9V, therefore selects R1 to be 180K Ω.
Below brief description is done to the principle that low-power consumption DC voltage of the present utility model compares circuit.Because the emitter of the first PNP pipe Q2 connects power supply V1 by the second resistance R2, collector is by the 6th resistance R6 ground connection, base stage connects power supply V1 by the 9th resistance R9, therefore forms an on state threshold voltage in the base stage of the first PNP pipe Q2, is about 4.3V in present embodiment.
Input voltage VHH is after the first resistance R1, the 5th resistance R5 and the 4th resistance R4 dividing potential drop, if at the voltage of the first PNP pipe Q2 base stage higher than above-mentioned on state threshold voltage, first PNP pipe cut-off, therefore the 2nd NPN pipe Q7 base voltage is also close to 0V, therefore the 2nd NPN pipe Q7 ends, and the detection voltage V_DETECION that output terminal exports is high level.
Along with the decline of input voltage VHH, when when the base stage place voltage of the first PNP pipe Q2 is lower than this on state threshold voltage, the rapid conducting of first PNP pipe Q2, therefore the base emitter voltage difference of the 2nd NPN pipe Q7 is higher than 0.7V, therefore the 2nd NPN pipe Q7 conducting, now its collector emitter voltage difference is minimum, therefore, the value detecting voltage V_DETECTION is determined by the 3rd resistance R3 and the 7th resistance R7 dividing potential drop, because the resistance of the 3rd resistance R3 is much smaller than the 7th resistance R7, therefore detecting voltage V_DETECTION is low level, close to 0V.
During owing to normally working, input voltage VHH is higher than threshold value, and two transistors are all in cut-off state, and therefore whole circuit power consumption only consumed by the first resistance R1 and the 5th resistance R5, and stand-by power consumption is lower.
Fig. 2-Fig. 3 is the computer analog oscillogram of this circuit, and as shown in the figure, during work, input voltage VHH is linear decline from 12V, is down to identical with threshold voltage V_GATE, about during 200ms, reduces to 0 when about 55ms.Detect output voltage V_DETECTION, as shown in Figure 2, along with the reduction at input voltage VHH, detect voltage V_DETECTION input voltage VHH drop into equal with threshold voltage V_GATE near, the present embodiment is 8.8V, become low level from high level, logic level is equivalent to become 0 from 1.Inversion section is amplified as shown in Figure 3, whole switching time is 1.1ms, in this 1.1ms, the amplitude of falling of input voltage VHH is 8.7846-8.7184=0.06V, visible low-power consumption DC voltage of the present utility model compares circuit and has reaction velocity faster, can the falling of corresponding input voltage fast, and the low-power consumption DC voltage of the present embodiment compares circuital current is only 39.3 μ A, whole circuit power consumption is 4.6 μ W, achieves low-power consumption.
Low-power consumption DC voltage of the present utility model compares circuit and can react rapidly when input voltage VHH falls at threshold voltage V_GATE, output voltage is reversed to low level 0, the voltage detecting of the highest 40V can be supported, highly sensitive, the fuzzy excessive window detecting voltage is less than 0.1V, reaction time is less than 1ms, and power consumption is less than 0.01 μ W, and structure simple realization cost is low.
Claims (5)
1. low-power consumption DC voltage compares a circuit, comprising the input end for inputting input voltage and the output terminal for output detections voltage, it is characterized in that, also comprise:
The first resistance between described input end and ground in sequential series and the 5th resistance, the node that described first resistance is connected with described 5th resistance is first node;
The first transistor, the emitter of described the first transistor is connected with power supply by the second resistance, and collector is by the 6th resistance eutral grounding, and base stage is connected with power supply by the 9th resistance;
The base stage of the first transistor is connected with first node;
Transistor seconds, the collector of described transistor seconds is connected with power supply by the 7th resistance, base stage is connected with the collector of described the first transistor by the 8th resistance, and emitter is by the 3rd resistance eutral grounding, and described 7th resistance is greater than described 3rd resistance;
The collector of described transistor seconds is connected with described output terminal.
2. the low-power consumption DC voltage recorded as claim 1 compares circuit, and it is characterized in that, also comprise the 4th resistance, the base stage of described the first transistor is connected with described first node by described 4th resistance.
3. the low-power consumption DC voltage recorded as claim 2 compares circuit, and it is characterized in that, the resistance of described first resistance sets according to compare threshold size.
4. the low-power consumption DC voltage recorded as claim 2 compares circuit, and it is characterized in that, the resistance of described 7th resistance is 10K Ω, and the resistance of described 3rd resistance is 10 Ω.
5. the low-power consumption DC voltage recorded as claim 2 compares circuit, and it is characterized in that, described the first transistor is PNP transistor, and described transistor seconds is NPN transistor.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201520157260.XU CN204515677U (en) | 2015-03-19 | 2015-03-19 | A kind of low-power consumption DC voltage compares circuit |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201520157260.XU CN204515677U (en) | 2015-03-19 | 2015-03-19 | A kind of low-power consumption DC voltage compares circuit |
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| CN204515677U true CN204515677U (en) | 2015-07-29 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106033243A (en) * | 2015-03-19 | 2016-10-19 | 上海贝岭股份有限公司 | Low-power DC voltage comparison circuit |
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- 2015-03-19 CN CN201520157260.XU patent/CN204515677U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106033243A (en) * | 2015-03-19 | 2016-10-19 | 上海贝岭股份有限公司 | Low-power DC voltage comparison circuit |
| CN106033243B (en) * | 2015-03-19 | 2023-09-29 | 上海贝岭股份有限公司 | Low-power consumption direct-current voltage comparison circuit |
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