High-low voltage differential amplification circuit for BMS

Abstract

The invention discloses a high-low voltage differential amplification circuit for a BMS, and the circuit comprises an operation amplification circuit, and the input end of the operation amplificationcircuit is connected with a voltage reduction circuit. The voltage reduction circuit comprises a first resistor R1 connected with a first input voltage VCn and a second resistor R2 connected with a second input voltage VC<n-1>; the first resistor R1 is connected with a third resistor R3; the third resistor R3 is grounded; the first resistor R1 is also connected with the normal-phase input end of the operational amplifier circuit; the second resistor R2 is connected with a fourth resistor R4; the fourth resistor R4 is connected with the voltage output end Vout of the operational amplifier circuit; and the second resistor R2 is also connected with the negative phase input end of the operational amplifier circuit. The high-voltage switch cabinet can be effectively applied to a high-voltage environment, the problem of high failure rate in the high-voltage environment is solved, and the service life of a product is greatly prolonged; in addition, the invention also has the characteristics of high amplification coefficient, good linearity, high precision and strong anti-interference capability.

Description

technical field [0001] The invention relates to a differential amplifier circuit, in particular to a high and low voltage differential amplifier circuit for BMS. Background technique [0002] With the advancement of the national new energy strategy, high-capacity and high-power lithium battery packs have attracted more and more attention from the market. Early lithium batteries were mainly used in some digital devices with low voltage and power. Now more application requirements are in new energy vehicles, such as electric bicycles, electric motorcycles, electric vehicles and other large-scale batteries that require high voltage and high power output. on durable goods. BMS (Battery Management System) is one of the most important components on a lithium battery pack, and the differential amplifier circuit used for voltage measurement in the BMS also plays a pivotal role. The differential amplifier circuit includes many MOS tubes, and a considerable part of the MOS tubes are...

AI Technical Summary

Problems solved by technology

The differential amplifier circuit includes many MOS tubes, and a considerable part of the MOS tubes are more suitable for medium-voltage and low-voltage operating environments. As the performance of lithium battery packs is getting better and better, the voltage value processed by BMS is also increasing. The high-voltage operating environment can easily lead to MOS tube failure, thereby reducing the service life of the BMS

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