A Self-contained Trimmable Low Quiescent Current Overvoltage Detector

This paper presents a low-power self-contained overvoltage detector. Compared with conventional detectors that consist of stacked Zener diodes, the proposed structure can trim the threshold with binary codes to accommodate system-level changes. The proposed structure enables trimming by adding a decoder, a biasing circuit, and switches in parallel with Zener diodes. The newly configured structure forms a standalone detector that can operate independently and be powered from the supply under detection with negligible current addition. The proposed structure is applicable to any high-voltage process that contains N-type isolation layer and needs no high-voltage device. The proposed circuit with three bits adjustment circuit was fabricated in a 0.18 mu m Bipolar-CMOS-DMOS (BCD) process, the overvoltage threshold can be adjusted from 8 to 38 V with post trim variation of +/- 2.5 V. The measured quiescent current was around 0 mu A at 10 V and 28 mu A at 38 V, which was comparable to the current consumption in a conventional structure with 38 V overvoltage threshold. (c) 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.