A5191HRT AMIS HART™ Modem 1. Features Can be used in designs presently using the SYM20C15 Single-chip, half-duplex 1200 bits per second FSK modem Bell 202 shift frequencies of 1200Hz and 2200Hz - power supply Transmit-signal wave shaping Receive band-pass filter Low power: optimal for intrinsically safe applications patible Internal oscillator requires crystal or ceramic resonator Meets HART physical layer requirements Industrial temperature range of -40°C to +85°C Available in 28-pin and 32-pin LQFP packages 2. Description The A5191HRT is a single-chip, CMOS modem for use in highway addressable remote transducer (HART) field instruments and masters. The modem and a few external ponents provide all of the functions needed to satisfy HART physical layer requirements including modulation, demodulation, receive filtering, carrier detect, and transmit-signal shaping. The A5191HRT is patible with the SYM20C15. See the Pin Description and Functional Description sections for details on patibility with the SYM20C15. The A5191HRT 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 munications. Figure 2-1 28-Pin Pinout Diagrams (green & non-green) Figure 2-2 32-Pin LQFP Pinout Diagrams (green & non-green) Table 2-1 Pinout Summary 28-Pin , A5191HRTP/Pg (12197-504/508) Pin N0. Signal Name Type Pin description 1 TEST1 Input Connect to VSS 2 TEST2 - No connect 3 TEST3 - No connect 4 TEST4 - No connect 5 TEST5 Input Connect to VSS 6 INRESET Input Reset all digital logic when low 7 TEST7 Input Connect to VSS 8 TEST8 Input Connect to VSS 9 TEST9 Input Connect to VSS 10 OTXA Output Output transmit analog, FSK mod