CN216411410U - Series resistance detection circuit - Google Patents
Series resistance detection circuit Download PDFInfo
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- CN216411410U CN216411410U CN202122775934.0U CN202122775934U CN216411410U CN 216411410 U CN216411410 U CN 216411410U CN 202122775934 U CN202122775934 U CN 202122775934U CN 216411410 U CN216411410 U CN 216411410U
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Abstract
The utility model discloses a series resistance detection circuit, which relates to the technical field of circuits and comprises a circuit to be detected and a current detection circuit, wherein the circuit to be detected comprises a current IREF end, a switch S1, a switch S2, a switch S3, a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a resistor RLOAD; the current detection circuit comprises a transconductance GM, an operational amplifier OP, a resistor R11, a resistor R22, a resistor R33, a P-type MOS tube MP1, a P-type MOS tube MP2, a P-type MOS tube MP3, a P-type MOS tube MP4, an N-type MOS tube MN1, an IOUT end and a voltage VDD end. The voltage values at two ends of the resistor to be detected are adjusted in a stepping mode, the influence of resistor deviation is reduced, the detection precision is improved, the input voltage is converted into the output current through the rail-to-rail transconductance operational amplifier structure, the transconductance is constant, so that the detection circuit can obtain the current with high precision, and the current is output through a negative feedback loop formed by two stages of operational amplifiers.
Description
Technical Field
The utility model relates to the technical field of circuits, in particular to a series resistance detection circuit.
Background
Current sensing technology is widely used in various areas of modern industry, such as power management systems, over-current protection circuits, programmable current sources, linear and switched mode power supplies, and battery chargers. Common current detection modes include a series resistor, a power tube on-resistance, a power tube mirror copy and the like.
The series resistor causes power loss, for a series resistor detection circuit, the resistance value deviation of a resistor to be detected in an actual circuit is usually 20%, and the output power changes +/-0.2 mW if 1 kilohm resistor flows 1mA current, but the detection precision is higher; the conducting resistance of the power tube can perform overcurrent protection, but the conducting resistance is greatly influenced by factors such as process, temperature, power supply and the like, and is difficult to apply to high-precision current detection; the current of the detection tube of the power tube mirror image copy is small, the power consumption is reduced, but the detection precision is not high. The methods have defects in power consumption, speed and precision, and a series resistance detection circuit is selected for high-precision requirements.
SUMMERY OF THE UTILITY MODEL
The utility model aims to solve the technical problem of providing a series resistor detection circuit aiming at the defects of the background technology, which carries out step adjustment on a resistor to be detected, the voltage at two ends of the resistor to be detected is provided for a current detection module, and the current detection circuit converts the voltage difference into output current.
The utility model adopts the following technical scheme for solving the technical problems:
a series resistance detection circuit comprises a circuit to be detected and a current detection circuit, wherein the circuit to be detected comprises a current IREF end, a switch S1, a switch S2, a switch S3, a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a resistor RLOAD; the current detection circuit comprises a transconductance GM, an operational amplifier OP, a resistor R11, a resistor R22, a resistor R33, a P-type MOS tube MP1, a P-type MOS tube MP2, a P-type MOS tube MP3, a P-type MOS tube MP4, an N-type MOS tube MN1, an IOUT end and a voltage VDD end;
wherein, IREF terminal is connected to the positive input terminal of transconductance GM, one terminal of resistor R1, one terminal of switch S1, the other terminal of switch S1 is connected to the other terminal of resistor R1, one terminal of resistor R2, one terminal of switch S2, the other terminal of switch S2 is connected to one terminal of switch S3, the other terminal of resistor R2 and one terminal of resistor R3, the other terminal of switch S3 is connected to the other terminal of resistor R3 and one terminal of resistor R4, the other terminal of resistor R4 is connected to one terminal of resistor RLOAD and the negative input terminal of transconductance GM, the other terminal of resistor RLOAD is grounded, the output terminal of transconductance GM is connected to the negative input terminal of operational amplifier OP and one terminal of resistor R11, the other terminal of resistor R11 is grounded, the positive input terminal of operational amplifier OP is connected to one terminal of resistor R22 and the source of N-type MOS MN1, the output terminal of operational amplifier OP is connected to the gate of N-type MOS MN1, the drain of the N-type MOS transistor MN1 is connected to one end of the resistor R33, the gate of the P-type MOS transistor MP3, and the gate of the P-type MOS transistor MP4, respectively, the other end of the resistor R33 is connected to the drain of the P-type MOS transistor MP3, the gate of the P-type MOS transistor MP1, and the gate of the P-type MOS transistor MP2, respectively, the source of the P-type MOS transistor MP3 is connected to the drain of the P-type MOS transistor MP1, the source of the P-type MOS transistor MP1 is connected to the source of the P-type MOS transistor MP2 and the voltage VDD terminal, the drain of the P-type MOS transistor MP2 is connected to the source of the P-type MOS transistor MP4, and the drain of the P-type MOS transistor MP4 is connected to the IOUT terminal.
Compared with the prior art, the utility model adopting the technical scheme has the following technical effects:
the utility model relates to a series resistor detection circuit, which comprises a circuit to be detected and a current detection circuit, wherein the circuit to be detected and the current detection circuit are used for carrying out stepping adjustment on a resistor to be detected, the voltage at two ends of the resistor to be detected is supplied to a current detection module, and the current detection circuit converts the voltage difference into output current; the voltage values at two ends of the resistor to be detected are adjusted in a stepping mode, the influence of resistance deviation is reduced, the detection precision is improved, the input voltage is converted into the output current through the rail-to-rail transconductance operational amplifier structure, the transconductance is constant, so that the detection circuit can obtain the current with high precision, and the current is output through a negative feedback loop formed by two stages of operational amplifiers.
Drawings
Fig. 1 is a circuit diagram of a series resistance detection circuit of the present invention.
Detailed Description
The technical scheme of the utility model is further explained in detail by combining the attached drawings:
the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
A series resistance detection circuit comprises a circuit to be detected and a current detection circuit, wherein the circuit to be detected comprises a current IREF end, a switch S1, a switch S2, a switch S3, a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a resistor RLOAD;
the current detection circuit comprises a transconductance GM, an operational amplifier OP, a resistor R11, a resistor R22, a resistor R33, a P-type MOS tube MP1, a P-type MOS tube MP2, a P-type MOS tube MP3, a P-type MOS tube MP4, an N-type MOS tube MN1, an IOUT end and a voltage VDD end;
wherein, IREF terminal is connected to the positive input terminal of transconductance GM, one terminal of resistor R1, one terminal of switch S1, the other terminal of switch S1 is connected to the other terminal of resistor R1, one terminal of resistor R2, one terminal of switch S2, the other terminal of switch S2 is connected to one terminal of switch S3, the other terminal of resistor R2 and one terminal of resistor R3, the other terminal of switch S3 is connected to the other terminal of resistor R3 and one terminal of resistor R4, the other terminal of resistor R4 is connected to one terminal of resistor RLOAD and the negative input terminal of transconductance GM, the other terminal of resistor RLOAD is grounded, the output terminal of transconductance GM is connected to the negative input terminal of operational amplifier OP and one terminal of resistor R11, the other terminal of resistor R11 is grounded, the positive input terminal of operational amplifier OP is connected to one terminal of resistor R22 and the source of N-type MOS MN1, the output terminal of operational amplifier OP is connected to the gate of N-type MOS MN1, the drain of the N-type MOS transistor MN1 is connected to one end of the resistor R33, the gate of the P-type MOS transistor MP3, and the gate of the P-type MOS transistor MP4, respectively, the other end of the resistor R33 is connected to the drain of the P-type MOS transistor MP3, the gate of the P-type MOS transistor MP1, and the gate of the P-type MOS transistor MP2, respectively, the source of the P-type MOS transistor MP3 is connected to the drain of the P-type MOS transistor MP1, the source of the P-type MOS transistor MP1 is connected to the source of the P-type MOS transistor MP2 and the voltage VDD terminal, the drain of the P-type MOS transistor MP2 is connected to the source of the P-type MOS transistor MP4, and the drain of the P-type MOS transistor MP4 is connected to the IOUT terminal.
The utility model firstly carries out step adjustment on the voltage values at two ends of the resistor to be detected, reduces the influence of resistor deviation, improves the detection precision, converts the input voltage into the output current through the rail-to-rail transconductance operational amplifier structure, and can obtain the current with high precision because the transconductance is constant, and then outputs the current through the negative feedback loop formed by the two stages of operational amplifiers.
While certain exemplary embodiments of the present invention have been described above by way of illustration only, it will be apparent to those of ordinary skill in the art that the described embodiments may be modified in various different ways without departing from the spirit and scope of the utility model. Accordingly, the drawings and description are illustrative in nature and should not be construed as limiting the scope of the utility model.
Claims (1)
1. A series resistance detection circuit, characterized by: comprising a circuit to be checked comprising a current I and a current detection circuitREFTerminal, switch S1, switch S2, switch S3, resistor R1, resistor R2, resistor R3, resistor R4 and resistor RLOAD(ii) a The current detection circuit comprises a transconductance GM, an operational amplifier OP, a resistor R11, a resistor R22, a resistor R33, a P-type MOS tube MP1, a P-type MOS tube MP2, a P-type MOS tube MP3, a P-type MOS tube MP4, an N-type MOS tube MN1, an IOUTTerminal, voltage VDD terminal;
wherein, IREFThe ends of the switch S2 are respectively connected with one end of a switch S3, the other end of a resistor R2 and one end of a resistor R3, the other end of the switch S3 is respectively connected with the other end of a resistor R3 and one end of a resistor R4, the other end of a resistor R4 is respectively connected with the positive input end of the transconductance GM, one end of a resistor R1 and one end of a switch S1, the other end of the switch S1 is respectively connected with the other end of the resistor R1, one end of the resistor R2 and one end of the switch S2, the other end of the switch S2 is respectively connected with one end of a resistor R3, the other end of the resistor R3 and one end of the resistor R4, and the other end of the resistor R4 is respectively connected with the other end of the resistor R4625LOADAnd a negative input terminal of transconductance GM, a resistor RLOADThe output end of the transconductance GM is respectively connected with the negative input end of the operational amplifier OP and one end of the resistor R11, the other end of the resistor R11 is grounded, the positive input end of the operational amplifier OP is respectively connected with one end of the resistor R22 and the source electrode of the N-type MOS transistor MN1, and the output end of the operational amplifier OP is connected with the N-type M1The grid of an OS tube MN1, the drain of an N-type MOS tube MN1 is respectively connected with one end of a resistor R33, the grid of a P-type MOS tube MP3 and the grid of a P-type MOS tube MP4, the other end of the resistor R33 is respectively connected with the drain of a P-type MOS tube MP3, the grid of a P-type MOS tube MP1 and the grid of a P-type MOS tube MP2, the source of a P-type MOS tube MP3 is connected with the drain of a P-type MOS tube MP1, the source of a P-type MOS tube MP1 is respectively connected with the source of the P-type MOS tube MP2 and a voltage VDD end, the drain of the P-type MOS tube MP2 is connected with the source of a P-type MOS tube MP4, and the drain of the P-type MOS tube MP4 is connected with IOUTAnd (4) an end.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122775934.0U CN216411410U (en) | 2021-11-14 | 2021-11-14 | Series resistance detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122775934.0U CN216411410U (en) | 2021-11-14 | 2021-11-14 | Series resistance detection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216411410U true CN216411410U (en) | 2022-04-29 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202122775934.0U Active CN216411410U (en) | 2021-11-14 | 2021-11-14 | Series resistance detection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216411410U (en) |
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2021
- 2021-11-14 CN CN202122775934.0U patent/CN216411410U/en active Active
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