Microcyber HT1200M User Manual Download Page 19

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HART Modem ASIC | HT1200M | Page

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Summary of Contents for HT1200M

Page 1: ...MICROCYBER HT1200M User Manual HART Modem ASIC According to HCF_SPEC 54 Version 1 1 Date 07 12...

Page 2: ...http www microcyber fieldbus com Revision History Version Release Date Detail of Changes 1 1 07 12 22 First release...

Page 3: ...0M Pin Descriptions 7 List of Figures Figure 1 HT1200M Hart Modem Typical Application 6 Figure 2 a 28Pin PLCC Pinout Package b 32Pin LQFP Pinout Package 6 Figure 3 Reset Timing 8 Figure 4 HT1200M Bloc...

Page 4: ...ith the SYM20C15 The HT1200M 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...

Page 5: ...ldbus com HART Modem ASIC HT1200M Page Email fang siqi microcyber cn 6 Typical Application Figure 1 HT1200M Hart Modem Typical Application Pin Assignment a b Figure 2 a 28Pin PLCC Pinout Package b 32P...

Page 6: ...ICDREF input 12 9 Carrier detect reference voltage OCBIAS output 13 10 Comparator bias current TEST10 input 14 11 Connect to Vss VDDA power 15 13 Analog supply voltage IRXA input 16 14 FSK modulated H...

Page 7: ...holds all the digital logic in Reset During normal operation INRESET should be at VDD INRESET should be held low for a minimum of 10 ns after VDD 2 5 V as shown in Figure 3 INRTS Request To Send Figu...

Page 8: ...l outputs the digital receive data When the received signal IRXA is 1200 Hz ORXD outputs logic high When the received signal IRXA is 2200 Hz ORXD outputs logic low ORXD is qualified internally with OC...

Page 9: ...analog receive circuitry band pass filters the received signal for input to the modem and the carrier detect circuitry The oscillator provides the modem with a stable time base using either a simple...

Page 10: ...cuit produce received serial data at ORXD Maximum demodulator jitter is 12 percent of one bit given input frequencies within HART specifications a clock frequency of 460 8 kHz 1 0 percent and zero inp...

Page 11: ...unt to 3 33 ms when the received signal is 1200 Hz and to 1 82 ms when the received signal is 2200 Hz ANALOG RECEIVER CIRCUITRY Voltage References The HT1200M requires two voltage references IAREF and...

Page 12: ...he input impedance of the entire filter is greater than 150 ohm at frequencies below 50 kHz Figure 8 Receive Schematic OSCILLATOR The HT1200M requires a 460 8 kHz clock signal on OXTL This can be prov...

Page 13: ...0 8 kHz clock as shown in Figure 10 rather than the internal oscillator because of the high cost and low availability of ceramic resonators In addition the HT 1200M consumes less current when an exter...

Page 14: ...http www microcyber fieldbus com HART Modem ASIC HT1200M Page Email fang siqi microcyber cn 15 Package Information Figure 10 LQFP32...

Page 15: ...http www microcyber fieldbus com HART Modem ASIC HT1200M Page Email fang siqi microcyber cn 16 Figure 11 PLCC28...

Page 16: ...ut Voltage Low 2 7 5 5V 0 3 VDD V VIL INRESET INRTS 2 7 3 3V 0 9 1 2 1 4 V VIH Input Voltage 2 7 5 5V 0 7 VDD V VIH INRESET INRTS 2 7 3 3V 1 3 1 8 2 3 V VOL Output Voltage Low IOL 1 8mA 2 7 3 3V 0 4 V...

Page 17: ...nge 150 0 15 0 025 VDD 0 15 V s kHz V s IRXAC Carrier Detect Receive Filter Input Leakage Current 500 nA OTXA Modulator Output Frequency Mark Logic1 Frequency Space Logic0 Amplitude IAREF1 235V Slop 3...

Page 18: ...siqi microcyber cn 19 CERAMIC RESONATOR EXTERNAL CLOCK SPECIFICATIONS VDD 2 7V to 5 5V VSS OV TA 40 C to 85 C Parameter Min Typical Max Units Resonator Tolerance 460 8 1 kHz Frequency External Clock...

Page 19: ...ge Email fang siqi microcyber cn 20 YOUR FIELDBUS EXPERT CONTACT INFORMATION Address 17 8 Wensu Street Hunnan New District Shenyang China Website www microcyber fieldbus com Phone 86 24 31217278 86 24...