CN107786172A - Opamp input terminal protection circuit - Google Patents
Opamp input terminal protection circuit Download PDFInfo
- Publication number
- CN107786172A CN107786172A CN201610799436.0A CN201610799436A CN107786172A CN 107786172 A CN107786172 A CN 107786172A CN 201610799436 A CN201610799436 A CN 201610799436A CN 107786172 A CN107786172 A CN 107786172A
- Authority
- CN
- China
- Prior art keywords
- circuit
- operational amplifier
- input terminal
- opamp
- input
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
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Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/30—Modifications of amplifiers to reduce influence of variations of temperature or supply voltage or other physical parameters
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/52—Circuit arrangements for protecting such amplifiers
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Tone Control, Compression And Expansion, Limiting Amplitude (AREA)
- Amplifiers (AREA)
Abstract
The invention belongs to electronic circuit technology, is related to a kind of opamp input terminal protection circuit.The opamp input terminal protection circuit includes the operational amplifier A and its peripheral circuit between signal input part and output end；The input of the operational amplifier is provided with a pressure difference amplitude limiter circuit；The signal input part of whole circuit is also connected with a voltage clamp circuit by bypass.The present invention can stablize opamp input terminal voltage, ensure circuit normal work.
Description
Technical field
The invention belongs to electronic circuit technology, is related to a kind of opamp input terminal protection circuit.
Background technology
Operational amplifier is actually a Differential Input, multistage, direct-coupling, plus and blowup circuit, with integrated electricity
For road technique productions in a circuit of single-chip integrated, it has two differential input ends, one or two output ends, two confessions
Electric power end.Under different circuit conditions, opamp input terminal may because fault or it is unstable and caused by input electricity
Pressure transfinites, and positive-negative input end pressure difference is excessive, have impact on its normal work and circuit lifetime.
The content of the invention
It can stablize opamp input terminal voltage the technical problem to be solved by the invention is to provide one kind, ensure
The opamp input terminal protection circuit of circuit normal work.
The opamp input terminal protection circuit of the present invention includes the computing between signal input part and output end
Amplifier A and its peripheral circuit；The input of the operational amplifier is provided with a pressure difference amplitude limiter circuit；The letter of whole circuit
Number input is also connected with a voltage clamp circuit by bypass.
The pressure difference amplitude limiter circuit includes a bipolar transistor T；Bipolar transistor T is connected across operational amplifier
Between positive-negative input end, base stage and emitter stage short circuit, operational amplifier positive input is connected to, colelctor electrode is connected to computing and put
Big device reverse input end.
The voltage clamp circuit include a pair of switching diode D1 being connected in reverse parallel between signal input part and ground terminal,
D2, electric capacity C6, C7 are also respectively connected between switching diode D1, D2 and earth terminal, the Node connectedness positive electricity between D1 and C6
Source+VCC ends, the Node connectedness negative supply-VCC ends between D2 and C7.
The present invention, using PN junction wire characteristic, operational amplifier positive-negative input end pressure difference is limited by pressure difference amplitude limiter circuit
System is in the range of a PN junction pressure drop, so as to ensure that operational amplifier positive-negative input end does not deviate by the concept of " empty short ", and then
Ensure the normal work of operational amplifier.Also end using its PN junction conductive characteristic, can be input a signal into by clamp circuit in addition
In dc point position limitation setting voltage range.So as to ensure that opamp input terminal voltage stabilization, ensure the normal work of circuit
Make.
Brief description of the drawings
Fig. 1 is the circuit theory diagrams of the embodiment of the present invention.
Embodiment
As illustrated, the opamp input terminal protection circuit includes the fortune between signal input part and output end
Calculate amplifier A and its peripheral circuit；The input of the operational amplifier is provided with a pressure difference amplitude limiter circuit；Whole circuit
Signal input part is also connected with a voltage clamp circuit by bypass.
Pressure difference amplitude limiter circuit includes a bipolar transistor T；Bipolar transistor T is connected across the positive and negative of operational amplifier
Between input, base stage and emitter stage short circuit, operational amplifier positive input is connected to, colelctor electrode is connected to operational amplifier
Reverse input end.Using PN junction wire characteristic, operational amplifier positive-negative input end pressure difference is limited in a PN junction pressure drop scope
It is interior, so as to ensure that operational amplifier positive-negative input end does not deviate by the concept of " empty short ", and then ensure the normal of operational amplifier
Work.
Voltage clamp circuit includes a pair of switching diode D1, D2 being connected in reverse parallel between signal input part and ground terminal,
Electric capacity C6, C7 have been also respectively connected between switching diode D1, D2 and earth terminal, the Node connectedness positive supply between D1 and C6+
VCC ends, the Node connectedness negative supply-VCC ends between D2 and C7.
Claims (3)
1. a kind of opamp input terminal protection circuit, including the operational amplifier between signal input part and output end
A and its peripheral circuit；It is characterized in that：The input of the operational amplifier is provided with a pressure difference amplitude limiter circuit；Whole circuit
Signal input part also by bypass be connected with a voltage clamp circuit.
2. according to the opamp input terminal protection circuit described in claim power 1, it is characterized in that：Pressure difference amplitude limiter circuit includes
One bipolar transistor T；Bipolar transistor T is connected across between the positive-negative input end of operational amplifier, base stage and emitter stage
Short circuit, is connected to operational amplifier positive input, and colelctor electrode is connected to operational amplifier reverse input end.
3. according to the opamp input terminal protection circuit described in claim power 2, it is characterized in that：The voltage clamp circuit
Including a pair of switching diode D1, D2 being connected in reverse parallel between signal input part and ground terminal, switching diode D1, D2 and ground connection
Electric capacity C6, C7 have been also respectively connected between end, the Node connectedness positive supply+VCC ends between D1 and C6, the node between D2 and C7
Connect negative supply-VCC ends.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610799436.0A CN107786172A (en) | 2016-08-31 | 2016-08-31 | Opamp input terminal protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610799436.0A CN107786172A (en) | 2016-08-31 | 2016-08-31 | Opamp input terminal protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN107786172A true CN107786172A (en) | 2018-03-09 |
Family
ID=61451869
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610799436.0A Pending CN107786172A (en) | 2016-08-31 | 2016-08-31 | Opamp input terminal protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107786172A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111175559A (en) * | 2018-11-09 | 2020-05-19 | 基思利仪器有限责任公司 | Multi-stage current measurement architecture |
| WO2020220682A1 (en) * | 2019-04-30 | 2020-11-05 | 思瑞浦微电子科技（苏州）股份有限公司 | Input withstand voltage protection architecture |
| CN117169675A (en) * | 2023-09-01 | 2023-12-05 | 南京航空航天大学 | On-line monitoring circuit for conduction voltage drop of inverter-stage wide-temperature-zone power device |
-
2016
- 2016-08-31 CN CN201610799436.0A patent/CN107786172A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111175559A (en) * | 2018-11-09 | 2020-05-19 | 基思利仪器有限责任公司 | Multi-stage current measurement architecture |
| WO2020220682A1 (en) * | 2019-04-30 | 2020-11-05 | 思瑞浦微电子科技（苏州）股份有限公司 | Input withstand voltage protection architecture |
| US11316483B2 (en) | 2019-04-30 | 2022-04-26 | 3Peak Inc. | Input voltage endurance protection architecture |
| CN117169675A (en) * | 2023-09-01 | 2023-12-05 | 南京航空航天大学 | On-line monitoring circuit for conduction voltage drop of inverter-stage wide-temperature-zone power device |
| CN117169675B (en) * | 2023-09-01 | 2024-04-26 | 南京航空航天大学 | On-line monitoring circuit for conduction voltage drop of inverter-stage wide-temperature-zone power device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |