Method of Eliminating DC Offset in Cot Ripple Compensation Circuit

Abstract

The invention relates to a method for eliminating DC offset in a COT ripple compensation circuit, belonging to the technical field of power supply management. Including the sampling pulse S / H generation process and the offset elimination process, during the sampling pulse S / H generation process, the output signal LoopCom_OUT of the loop comparator of the acquisition system is input to the set terminal S of the SR flip-flop, and the constant on-time module of the acquisition system The output signal TonComp_OUT of the SR flip-flop is input to the clearing terminal R of the SR flip-flop, and the signal output from the inverting output terminal NQ of the SR flip-flop is delayed and processed, and the signal output from the non-inverting output terminal Q is jointly input to the AND gate for AND operation to obtain sample and hold Pulse S / H; In the process of offset elimination, sample and hold pulse S / H is used to control the extraction of DC information, and the extracted DC information is used in the ripple superposition module to eliminate the offset of the output voltage. The invention implements the output offset elimination of the converter by adding a DC offset elimination method in the DC flow extraction circuit without adding an additional offset elimination circuit.

Description

technical field [0001] The invention belongs to the technical field of power management, and in particular relates to a method for eliminating the output DC offset of a step-down converter with a constant on-time (Constant On Time, COT) control framework. Background technique [0002] Compared with the voltage control mode and the peak current control mode, the COT control mode does not require an error amplifier in the traditional sense, which enables the COT control mode to provide faster transient response while maintaining accuracy; the COT control mode provides The frequency stabilization within the full input voltage range is of great significance to the anti-electromagnetic interference characteristics; at the same time, the improvement of the efficiency of the COT control mode under light load is in line with the development trend of electronic products at the current stage. The COT control architecture is favored among power management chips. [0003] While COT bri...

AI Technical Summary

Problems solved by technology

Generally, the COT technology based on ripple control has a design compromise between the noise margin and the amount of DC offset introduced on the output. High noise immunity requires the compensation ripple to have sufficient amplitude, which will bring greater Output DC offset, the defect of DC offset is very prominent in high-precision applications

Images