Constant-current constant-power control circuit for DC-DC converter and implementation method

Abstract

The invention discloses a constant-current constant-power control circuit for a DC-DC converter. The circuit comprises a timer, a voltage loop error amplifier OP1, a current detection circuit and a comparator CMP1, and also comprises a comparator CMP2, a time sequence generation circuit, a charge pump circuit, an MOS tube PM1, and a divider. The divider is connected to the normal-phase input end of the comparator CMP2, and the inverting input end of the comparator CMP2 is connected with the current detection circuit. A CMPO interface of the time sequence generation circuit is connected with the output end of the comparator CMP1, a CMPO_2 interface is connected with the output end of the comparator CMP2, a CLK interface is connected with the output end of the timer, an Up interface is connected with an UP interface of the charge pump circuit, and a Down interface is connected with a DOWN interface of the charge pump circuit. The gate electrode of the MOS tube PM1 is connected with the output end CP_OUT of the charge pump circuit, the drain electrode of the MOS tube PM1 is grounded, and the non-inverting input end of the comparator CMP1 and the source electrode of the MOS tube PM1 are both connected to the output end of the voltage loop error amplifier OP1. The effects of low power loss, simple circuit structure and low cost are achieved.

Description

technical field [0001] The invention relates to the field of power supply management and energy conversion, in particular to a constant current and constant power control circuit used in DC-DC and its realization method. Background technique [0002] In the fields of energy conversion, power management, etc., in order to achieve constant current or constant power control, the existing method is generally to add a current detection element outside the chip to detect the input or output current, and then realize it by adding a loop selection circuit inside the chip. ;Such as figure 1 In the ordinary DC-DC constant current or constant power input and output control circuit shown, a current detection element such as a resistor or a current transformer is added outside the chip, and a current preamplifier, a multiplier, and a constant current / constant power loop are added inside. Loop error amplifier, and loop selection circuit, finally realize constant current / constant power co...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a DC-DC constant current constant power control circuit and its implementation method, which solves the problems of complex structure, high cost and large power loss in the existing control circuit

Images