Two-way positive-end current sampling module and circuit, switch circuit and current sampling method

Abstract

The invention provides a two-way positive-end current sampling module. According to the two-way positive-end current sampling module, one end of a resistor R5 is connected to a source electrode of a PMOS tube MP1, a source electrode of a PMOS tube MP4 and a source electrode of a PMOS tube MP5; one end of a resistor R6 is connected to a source electrode of a PMOS tube MP2; one end of the resistor R7 is connected to a source electrode of a PMOS tube MP3; a grid electrode of the PMOS tube MP1 is connected with a grid electrode of the PMOS tube MP2, a grid electrode of the PMOS tube MP3 and a drain electrode of MP1; a drain electrode of the PMOS tube MP1 is connected with a chip through a current source IS1, a drain electrode of the PMOS tube MP2 is connected with the chip through a current source IS2, and a drain electrode of the PMOS tube MP3 is connected with the chip through a current source IS2; a grid electrode of the PMOS tube MP4 is connected with the drain electrode of the PMOS tube MP2, and a grid electrode of the PMOS tube MP5 is connected with the drain electrode of the PMOS tube MP3; a drain electrode of the PMOS tube MP4 and a drain electrode of the PMOS tube MP5 are connected with one end of a resistor R8, and the other end of the resistor R8 is connected with the chip; one end of the resistor R8 is used for outputting voltage feedback signals VSEN. By the adoption of the two-way positive-end current sampling module, two-way high-accuracy current sampling is achieved.

Description

technical field [0001] The invention relates to the technical field of power supply integrated circuits, in particular to a high-precision dual-channel positive terminal current sampling control circuit applied to a switch-type regulator. Background technique [0002] Power converters are widely used in various electronic devices, and their function is to convert power from one form to another. A power converter is mainly composed of a power stage circuit and a control loop. The control loop is to keep the output voltage or output current of the power converter stable by adjusting the turn-on and turn-off time of the switch tube and rectifier tube in the power stage circuit when the input voltage and external load change. Therefore, it is very important to be able to accurately sample the load current. The current current sampling technology is mainly to test the voltage difference between the two ends of the sampling resistor. The sampling resistor can be the on-resistance...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art, to provide a dual-channel positive-terminal current sampling module, and a dual-channel positive-terminal current sampling circuit and a switch circuit based on the dual-channel positive-terminal current sampling module to solve existing problems. The sampling circuit structure in the technology is complex, the precision is low, and the current sampling consistency of each output branch cannot be guaranteed.

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