The NCN5192 is a single-chip, CMOS modem for use in highway addressable remote transducer (HART) field instruments and masters. The modem and a few external passive components provide all of the functions needed to satisfy HART physical layer requirements including modulation, demodulation, receive filtering, carrier detect, and transmit-signal shaping. In addition, the NCN5192 also has an integrated DAC for low-BOM current loop slave transmitter implementation. The NCN5192 uses phase continuous frequency shift keying (FSK)at 1200 bits per second. To conserve power the receive circuits are disabled during transmit operations and vice versa. This provides the half-duplex operation used in HART communications.