NXP remote keyless entry transponder family PCF7961

NXP remote keyless entry
transponder family PCF7961
Fully integrated remote keyless
entry solutions
Ideal for today’s advanced vehicle access applications, the PCF7961 security transponder, microcontroller
and radio transmitter IC fits compact key designs and ensures cost-effective solutions.
Features
} Single-chip security transponder and keyless entry solution
with on-chip UHF transmitter
} PCF7936/37 or PCF7938 (96-bit) family compatible
transponder operation
} Low-power RISC programmable device operation
} On-chip, PLL-based UHF transmitter (315/434 MHz)
} Programmable ASK/FSK modulation characteristics
} Up to seven command button inputs
} On-chip memory
- 8/16 Kbytes of E-ROM
- 512 bytes of EEPROM, 192 bytes of RAM
} Single lithium cell operation (2.1 to 3.6 V)
} Package: TSSOP20 or LSP
Today’s car buyers expect the convenience of a remote
keyless entry system. NXP continues to reduce system cost
for keyless entry and immobilization systems with the highly
integrated PCF7961 family. Combining a security transponder,
a RISC controller and a UHF transmitter, this family delivers
a true single-chip solution. Based on NXP’s low-power
8-bit microcontroller core, the family performs command
button scanning and data framing according to application
requirements. RISC timing is derived from an on-chip,
low-tolerance RC oscillator with a programmable system clock
as fast as 2 MHz. Generation of “keyless entry code hoping”
can employ the hard-wired transponder calculation unit or
any software-based algorithm, while synchronization can be
achieved via the contactless transponder interface.
Benefits
} Highly integrated for minimum board space and low bill of
materials
} Easy application
} Low power consumption
With the exception of a reference crystal and loop-antenna
matching circuitry, the on-chip UHF transmitter requires no
other external components. The RISC controller directly controls
the UHF transmitter and supports ASK and FSK modulation with
data rates up to 20 kbits/s (Manchester).
Powered by an external, single-cell lithium battery, the device
features a power-down mode, which minimizes quiescent
current.
upgrades. The transponder requires no battery supply, so full
operation is guaranteed, even when the battery is low.
The programmable power amplifier stabilizes the output power
to minimize carrier, over-temperature and battery-voltage
variations. Security transponder operation is compatible
with the PCF7936/37 & PCF7938 families, for simple system
A complete suite of on-chip memory is available. For customer
application software, up to 16 Kbyte of EROM are provided. For
extended data storage, the device offers 512 bytes of on-chip
EEPROM, with access control defined by the application.
PCF7961 block diagram
leaded stick package
CVFLD
15 nF
VFLD
MSDA
MSCL
VBAT
VDDA
XT1
IN2
E-ROM
(ROM)
8 Bit RISC (MRK II)
IN1
CONTACTLESS INTERFACE
PCF7961
4k
ROM
192 Byte
RAM
EEPROM
512 Byte
PAOUT
CALCULATION
UNIT
UHF
TRANSMITTER
INTERRUPT
CONTROL
TIMER
MODULATOR
P22 1
P21
RC
OSCILLATOR
I/O
VSS
P16
P15
P14
P11
POWER MANAGEMENT
Note
1. Button inputs or generic I/O, however
external p'up resp. p'down required
XT2
VSSA
P10
VSSPA
buttons
Li
3V
brb380
www.nxp.com
© 2012 NXP Semiconductors N.V.
All rights reserved. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. The
Date of release: April 2012
information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and
Document order number: 9397 750 17269
may be changed without notice. No liability will be accepted by the publisher for any consequence of its use. Publication thereof
Printed in the Netherlands
does not convey nor imply any license under patent- or other industrial or intellectual property rights.