A trimming circuit design with pre-trim and fuse protection

This paper adopts the dongbu 0.18 um process to design a digital trimming circuit that reduces the number of pins and improves trimming accuracy. This design effectively reduces the chip size and cost by multiplexing a data pin and a clock pin. The introduced pre-trim function reduces the adjustment steps in the final trimming process, improves the screening and adjustment efficiency on the production line, and reduces the workload in the subsequent trimming stage. In addition, in order to enhance reliability and reduce power consumption, the design integrates protection bit fuses; once the circuit parameters are determined, the trimming circuit is disabled through gating technology to prevent parameter changes caused by unexpected faults and ensure stable operation of the equipment. This technology has been applied to a reset watchdog chip, and simulation results show that specific data and clock inputs can accurately trim key parameters.