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© Copyright 2002 Texas Instruments Incorporated.

11-07-22-003

07/02

The LF base station IC TMS3705A allows an efficient development and

production of handheld RFID readers & vehicle immobilizers. This base

station IC drives the antenna of a TI-RFid transponder system to send

data modulated on the antenna signal, and to detect and demodulate

the response from the transponder. It allows also minimizing the

external component count.

The key functions of the base station IC TMS3705A are:

» Self-adapting to transponders with a resonance frequency

between 129 kHz – 140 kHz

» Supports all TI-RFid LF transponder functions

» Asynchronous and synchronous data transmission to the IC

» Power management for 5V operation

» Internal full bridge antenna driver

» PLL for internal clock generation of 16 MHz

» Overcurrent protection of antenna driver

Specifications:

Part Number

RI-TMS3705ADR

Operating Frequency

Typical 134.2kHz, FSK

Operating Voltage

4.5V to 5.5V DC

Current Consumption

Charge Phase (without antenna load) typical 8 mA;

max. 20mA

Sleep Mode (without I/O currents)

typical 15

µA;

max. 0.2mA

Interface to Micro Controller

Two wire multifunctional serial interface, 15625 baud

Antenna Inductivity

400

µH - 700µH recommended

ESD Protection (MILSTD 883)

-2000V to +2000V

Operating Temperature

-40

°C to +85°C

Storage Temperature

-40

°C to +100°C (125°C up to 1000hrs over lifetime)

Package / Pin count

SO 16 (10 mm x 6 mm)

Packing / Delivery

Tape on Reel, 2500 units per reel

Sample Set-up of a Transponder System

For more information, contact the sales office or distributor nearest you. This contact information can be found

on our web site at:

http://www.ti-rfid.com

LF Base Station IC TMS3705A

+1 2 V

GND

RXD

TXD

GND

TIRIS TRANSPONDER

RF MODULE

READER

ANTENNA

CONTROL MODULE

RS232

DRIVER

POWER

SUPPLY

µC

T IRIS READER

TMS37 05A

+5 V

IC