Control circuit for output line resistance compensation in DC-DC converter and implementation method

Abstract

The invention discloses a control circuit for output line resistance compensation in a DC-DC converter. The control circuit comprises a DC-DC converter having a comparator A1 and a resistor R1. A SETpin for sampling the output current IBUS of the DC-DC converter is introduced into the DC-DC converter. The SET pin is also externally connected with a resistor RSET to the ground. The negative pole of the comparator A1 and the resistor R1 are both connected to a V / I conversion circuit. The V / I conversion circuit is simultaneously connected to the SET pin, and is also grounded via a resistor R3 such that a current source ICMP is obtained. The ICMP is superimposed on the output current IBUSOUT, so that a dynamic voltage ICMP*R3 in direct proportion to the output voltage VBUSOUT corresponding tooutput current IBUSOUT is superimposed to the output voltage VBUSOUT, thereby achieving the dynamic compensation output of the output voltage VBUSOUT. The control circuit realizes the dynamic compensation of the line resistance loss by superimposing a voltage which changes positively with the output current at an output port, and can detect the output current and improve a charging effect.

Description

technical field [0001] The invention relates to a line resistance compensation method, in particular to a control circuit and a realization method for output line resistance compensation in DC-DC. Background technique [0002] The schematic diagram of the principle of traditional power supply equipment supplying power to external equipment is as follows: figure 1 As shown, the power supply voltage is converted to a stable output voltage VBUS by a DC-DC converter OUT , the DC-DC converter contains two insulated gate bipolar transistors, a logic driver, a pulse width modulator, an operational amplifier and two resistors, because there is a resistor R on the charging line WIRE , there will be a voltage drop loss, and the voltage obtained by the external device VBUS=VBUS OUT –IBUS OUT *R WIRE , it can be seen that the voltage obtained by the external device will increase with the output current IBUS OUT Increase and decrease, resulting in the voltage obtained by the externa...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a control circuit and implementation method for output line resistance compensation in DC-DC, to solve the problem that the compensation value of the existing compensation method cannot be dynamically changed according to the real-time output current, resulting in poor compensation effect

Images