CN-224203288-U - Differential high-precision voltage acquisition circuit and switch thereof
Abstract
The utility model relates to the technical field of switch power management systems, in particular to a differential high-precision voltage acquisition circuit and a switch thereof, which comprises an operational amplifier U4.2, a sampling resistor R1, a feedback resistor R13, a filter capacitor C3, a filter capacitor C4 and a filter capacitor C5, wherein the other end of the sampling resistor R1 is connected with the non-inverting input end of the operational amplifier U4.2, one end of the feedback resistor R13 is connected with the inverting input end of the operational amplifier U4.2, and the sampling resistor R1 and the feedback resistor R13 are adjustable resistors. When the utility model works, current passes through the sampling resistor R1, a voltage signal which is in direct proportion to the current is generated on the sampling resistor R1, the voltage signal is sent to the input end of the operational amplifier U4.2, the voltage signal is amplified and then output, and the amplified signal is processed by the filter capacitor C5, so that high-frequency interference components are removed, and the signal is smoother and more stable.
Inventors
- MO WEIBIN
- LIU JIANG
- HUANG YIXING
Assignees
- 广东优力普物联科技有限公司
Dates
- Publication Date
- 20260505
- Application Date
- 20250430
Claims (5)
- 1. The differential high-precision voltage acquisition circuit is characterized by comprising an operational amplifier U4.2, a sampling resistor R1, a feedback resistor R13, a filter capacitor C3, a filter capacitor C4 and a filter capacitor C5, wherein the operational amplifier U4.2 is used for amplifying an input voltage signal, one end of the sampling resistor R1 is connected with an external power supply, the other end of the sampling resistor R1 is connected with a non-inverting input end of the operational amplifier U4.2, the filter capacitor C4 is connected with the sampling resistor R1 in parallel, one end of the feedback resistor R13 is connected with an inverting input end of the operational amplifier U4.2, the other end of the feedback resistor R13 is connected with an output end of the operational amplifier U4.2, the filter capacitor C5 is connected with the feedback resistor R13 in parallel, the output end of the operational amplifier U4.2 is connected with one end of the filter capacitor C3, the other end of the filter capacitor C3 is grounded, and the sampling resistor R1 and the feedback resistor R13 are adjustable resistors.
- 2. The differential high-precision voltage acquisition circuit as set forth in claim 1, further comprising a resistor R3, a resistor R5 and a resistor R7, wherein one end of the resistor R5 is connected with the non-inverting input terminal of the operational amplifier U4.2, one end of the resistor R7 is connected with the inverting input terminal of the operational amplifier U4.2, one end of the resistor R3 is connected with the output terminal of the operational amplifier U4.2, and the other end of the resistor R3 is connected with one end of the filter capacitor C3.
- 3. A differential high-precision voltage acquisition circuit as set forth in claim 1 further comprising a diode Q1 and a diode Q2, the diode Q1 and the diode Q2 being connected to the output of the operational amplifier U4.2.
- 4. The differential high-precision voltage acquisition circuit as set forth in claim 1, wherein the operational amplifier U4.2 is of a type TP2412-SR.
- 5. A switch, characterized by comprising the differential high-precision voltage acquisition circuit as claimed in any one of claims 1 to 4.
Description
Differential high-precision voltage acquisition circuit and switch thereof Technical Field The utility model relates to the technical field of switch power management systems, in particular to a differential high-precision voltage acquisition circuit and a switch thereof. Background In current switch power management systems, the performance bottleneck of the voltage acquisition circuit has gradually emerged. The traditional voltage acquisition scheme mostly adopts a single-ended input operational amplification structure, the Common Mode Rejection Ratio (CMRR) is generally lower than 60dB, and the common mode noise interference is easy to occur in a complex electromagnetic environment. By taking typical application as an example, an OP07 amplifier circuit adopted by a power monitoring module of a certain type of switch has the power noise suppression capability attenuation reaching-30 dB/decade in a frequency band above 20kHz, so that the acquisition error exceeds +/-3% under a dynamic working condition. In addition, the existing design mostly adopts a feedback network with fixed resistance, the amplification factor adjustment is realized by changing a resistor, and the flexible configuration requirements of different current ranges cannot be met. These inherent drawbacks make it difficult for existing solutions to meet the accuracy requirements of the new generation data center switches for 0.5% of the power management system and real-time response requirements of the order of 200 μs, especially when handling POE (power over ethernet) device dynamic power adjustments, where voltage monitoring hysteresis or false positives are highly likely to occur. In the prior art, the voltage acquisition circuit has the defects of low precision and low stability, and cannot meet the requirements of a switch power management system on real-time and accurate power state monitoring. Disclosure of Invention The utility model provides a differential high-precision voltage acquisition circuit and a switch thereof, which are ingenious in design, wherein an operational amplifier U4.2 is used for amplifying an input voltage signal, current passes through a sampling resistor R1, a voltage signal which is in direct proportion to the current is generated on the sampling resistor R1, the voltage signal is sent to the input end of the operational amplifier U4.2 and is amplified and then output, the amplification factor is determined by the ratio of the sampling resistor R1 to a feedback resistor R13, and the amplified signal is processed by a filter capacitor C5 to remove high-frequency interference components, so that the signal is smoother and more stable. In order to solve the technical problems, the utility model adopts the following technical scheme: The utility model provides a differential high-precision voltage acquisition circuit which comprises an operational amplifier U4.2, a sampling resistor R1, a feedback resistor R13, a filter capacitor C3, a filter capacitor C4 and a filter capacitor C5, wherein the operational amplifier U4.2 is used for amplifying an input voltage signal, one end of the sampling resistor R1 is connected with an external power supply, the other end of the sampling resistor R1 is connected with a non-inverting input end of the operational amplifier U4.2, the filter capacitor C4 is connected with the sampling resistor R1 in parallel, one end of the feedback resistor R13 is connected with an inverting input end of the operational amplifier U4.2, the other end of the feedback resistor R13 is connected with an output end of the operational amplifier U4.2, the filter capacitor C5 is connected with the feedback resistor R13 in parallel, the output end of the operational amplifier U4.2 is connected with one end of the filter capacitor C3, the other end of the filter capacitor C3 is grounded, and the sampling resistor R1 and the feedback resistor R13 are adjustable resistors. The differential high-precision voltage acquisition circuit further comprises a resistor R3, a resistor R5 and a resistor R7, one end of the resistor R5 is connected with the non-inverting input end of the operational amplifier U4.2, one end of the resistor R7 is connected with the inverting input end of the operational amplifier U4.2, one end of the resistor R3 is connected with the output end of the operational amplifier U4.2, and the other end of the resistor R3 is connected with one end of the filter capacitor C3. The differential high-precision voltage acquisition circuit further comprises a diode Q1 and a diode Q2, and the diode Q1 and the diode Q2 are connected to the output end of the operational amplifier U4.2. Preferably, the model number of the operational amplifier U4.2 is TP2412-SR. The utility model also provides a switch which comprises the differential high-precision voltage acquisition circuit. The utility model has the beneficial effects that: The utility model has ingenious design, the operational amplifier U4.2 is used