Fieldbus interface control IC

This paper introduces FRONTIER-1; the first chip developed for Fieldbus Interface which integrates complete functions including the modem and the transceiver required for implementing H1 Fieldbus Physical Layer Specification (Wire media, Voltage mode, 31.25 kbps). FRONTIER-1 contains high-voltage bipolar devices to drive the bus, analog circuits such as Op-amps, comparators and a voltage reference for drive control, voltage regulation and filters, and CMOS for the modem circuits. The integration of the transceiver and the modem was accomplished by using high-voltage Bi-CMOS process technology. On transmitting, FRONTIER-1 adds the frame delimiters and preambles to the messages supplied by a host CPU, generates FCS (Frame Check Sequence), and performs Manchester encoding. Transmitted digital signal is converted to the analog signal on the bus. On receiving, the signal on the bus is digitized, and modem circuits decode Manchester data and check FCS, and a host CPU reads the messages.<>