This product series is a digital display instrument IC integrated with TRMS (2kHz), LCD display driver, built-in UART port (which can achieve AC and DC voltage), and AC and DC current. It supports instantaneous value and true effective value measurement. It can achieve a comprehensive measurement accuracy of 0.1% F.S in the case of four and a half digits. The OTP can be programmed in situ and the programming voltage is internally generated. Infrequently changing data such as calibration factors can be stored in OTP in place of external EEPROM.