On-chip 4to20mA reconfigurable current loop transmitter for smart sensor applications

Abstract

An on-chip 4to20mA reconfigurable current loop transmitter with four input channels for remote smart sensor applications is presented. The designed system includes: a like-HART protocol based on frequency-shift keying modulator (FSK) and demodulator to an efficient communication in industrial environment, a power management sub-system, a standard 4to20mA output and an embedded NVM memory (256 bytes) for calibration and identification purposes. The integrated circuit was fabricated in standard 0.6um CMOS technology occupying an área of 11.1mm2.