A High-precision Current Sense Circuit with Trimming for DC-DC Converts

Abstract

A high-precision current sense circuit with trimming is proposed to realize the over-current protection of the power management chip and improve its conversion efficiency. Based on solving the problem of voltage offset and current inrush caused by process deviation, this circuit can detect the value of the inductor current accurately. By designing the bandgap reference circuit and the reference voltage bias network, the required stable reference voltage and bias current can be obtained. The trimming bit selection circuit can realize the trimming function. This circuit is designed with TSMC 180nm 1P3M GEN2 process, and all circuits are verified by Cadence Spectre.