PCF7991AT/1081,118

Philips Semiconductors Product Profile PCF7991AT Advanced Basestation IC, ABIC Features General Description The PCF7991 is a highly integrated and powerful advanced basestation IC, ABIC, ideally suited for vehicle immobilisation applications. The device incorporates all necessary functions to facilitate reading and writing of transponders. Extended system operating range due to powerful AM/PM demodulation technique Ideally suited for "Intelligent Antenna" and "Active Antenna" architectures High antenna drive capabilities, CW: 200mAp Low antenna driver output resistance, 3.5 Excellent receiver sensitivity, 2mVpp Large receiver dynamic range Programmable clock divider, modulator, receiver gain and filter characteristics Fast "read after write" receiver settling characteristics On-chip receive EMI filter Antenna failure mode detection Few external components Operating supply voltage: 4.5 to 5.5 V Power down mode: 7 A @ 5.5 V 14-pin SO package The ABIC, PCF7991 employs a unique AM/PM demodulation technique that extends the system operating range compared with simple envelope detection. Optimised to operate with the Philips transponder family (PCF79xx), the ABIC can be used in combination with commonly available transponder that employ ASK modulation. ASK modulation and receive characteristics are widely programmable for powerful system adaptation. The ABIC fits "Intelligent Antenna" as well as "Active Antenna" applications. The carrier frequency can be derived from an on-chip oscillator or an external clock source. A wide range of clock frequencies can be applied due to the programmable on-chip clock divider circuitry. The device enables system diagnostic functions by antenna fail detection features. Communication with the device and the transponder is provided via the serial microcontroller interface. Employing CMOS technology, the device features low power operation and supports Idle and Powerdown modes. Minimum Application Circuitry 4.5 ... 5.5 V VDD XTAL1 XTAL2 PCF 7991 TX1 Modulation Pulse Gen. Clk Divider Timing Oscillator Antenna DOUT Driver Control Unit TX2 RX EMI Filter Synchron Demodulator QGND May 1998 To microcontroller SC Filter Amplifier CEXT Serial Interface Register VSS DIN CLK