Voltage clamping circuit with ±100 mV precision in high‐voltage OTA

Abstract

It is shown that precise output voltage clamping levels can be achieved under any operating condition by clamping the input of operational transconductance amplifier to a process insensitive reference and multiplexing the levels based on comparator decision. This circuit was implemented in a 40 V bipolar CMOS process. The fabricated circuit clamps the output voltage at 5.4 V with a precision of ±100 mV at 175°C on-chip junction temperature on the die. The input range for this circuit is between 100 mV and 25 V.