High-side current sampling circuit

Abstract

The invention discloses a high-side current sampling circuit comprising a sampling resistor R4 and a differential amplifier circuit, wherein the sampling resistor R4 is connected in series to a high voltage end of a sampled circuit; the differential amplifier circuit is connected to two ends of the sampling resistor R4 and comprises a grounding end which is grounded and used for amplifying and outputting the voltages at two ends of the sampling resistor R4, and the amplified voltage takes the grounding end as a reference point. As the differential amplifier circuit of the high-side current sampling circuit comprises the grounding end which is grounded, and the voltage amplified by the differential amplifying circuit, i.e., the sampling voltage, takes the grounding end as the reference point, the defect that the high-side current sampling circuit in the prior art is used for sampling by taking a power supply as the reference point is avoided and the technical problem is effectively changed.

Description

technical field [0001] The invention belongs to the technical field of current sampling and detection, and in particular relates to a high-end current sampling circuit. Background technique [0002] The high-end current sampling circuit is used in the technical field of current sampling and detection. By analyzing the sampling signal of the high-end current sampling circuit, the current of the sampled circuit can be detected, and then it can be detected whether there is a fault in the sampled circuit and what faults exist, and corresponding protection measures can be taken for the sampled circuit in time for the existing faults. [0003] In the prior art, the reference point for sampling by the high-end current sampling circuit is not the ground but the power supply of the sampled circuit. However, in the electrical environment of a car, the power supply varies greatly. For example, the power supply of a passenger car varies within 9 -16V, commercial vehicles are 18-32V, so...

AI Technical Summary

Problems solved by technology

[0003] In the prior art, the reference point for sampling by the high-end current sampling circuit is not the ground but the power supply of the sampled circuit. However, in the electrical environment of a car, the power supply varies greatly. For example, the power supply of a passenger car varies within 9 -16V, commercial vehicles are 18-32V, so the sampled voltage will change with the power supply, at this time, the reference point of current sampling is changing, and the collected data cannot be applied

[0004] It can be seen that the existing high-end current sampling circuit has the disadvantage of taking the power supply as a reference for sampling, which brings difficulties to high-side current sampling

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