PCF7991AT Datasheet, PDF (1/1 Pages) NXP Semiconductors – Advanced Basestation IC, ABIC

Philips Semiconductors
Product Profile
PCF7991AT
Advanced Basestation IC, ABIC
Features
• 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 Ω
• 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: 7µA @ 5.5 V
• 14-pin SO package
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.
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 Clk Divider
Oscillator
Pulse Gen.
Timing
Antenna
Driver
Control
Serial
TX2
Unit
Interface
To microcontroller
DOUT
DIN
CLK
RX
EMI
Synchron
SC Filter
Register
Filter Demodulator Amplifier
QGND
CEXT
VSS
May 1998