TMS3705 Datasheet, PDF (1/23 Pages) Texas Instruments – TRANSPONDER BASE STATION IC

TMS3705
www.ti.com
11-07-22-003 – SCBS881B – JANUARY 2010 – REVISED APRIL 2010
TRANSPONDER BASE STATION IC
Check for Samples: TMS3705
FEATURES
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• Base Station IC for TI-RFid™ RF Identification
Systems
• Drives Antenna
• Sends Modulated Data to Antenna
• Detects and Demodulates Transponder
Response (FSK)
• Short-Circuit Protection
• Diagnosis
• Sleep-Mode Supply Current: 0.2 mA
• Designed for Automotive Requirements
• 16-Pin SOIC (D) Package
DESCRIPTION
The transponder base station IC is used to drive the antenna of a TI-RFid™ transponder system, to send data
modulated on the antenna signal, and to detect and demodulate the response of the transponder. The response
of the transponder is a FSK signal (frequency shift keyed). The high or low bits are coded in two different
high-frequency signals (134.2 kHz for low bits and 123 kHz for high bits, nominal). The transponder induces
these signals in the antenna coil according an internally stored code. The energy the transponder needs to send
out the data is stored in a charge capacitor in the transponder. The antenna field charges this capacitor in a
preceding charge phase. The IC has an interface to an external microcontroller.
There are two configurations for the clock supply to both the microcontroller and the base station IC:
1. Microcontroller and base station IC are supplied with a clock signal derived from only one resonator: The
resonator is attached to the microcontroller. The base station IC is supplied with a clock signal driven by the
digital clock output of the microcontroller. The clock frequency is either 4 MHz or 2 MHz depending on the
selected microcontroller type.
2. Both the microcontroller and the base station have their own resonator.
The base station IC has a PLL on-chip that generates a clock frequency of 16 MHz for internal clock supply only.
The TMS3705BDRG4 is optimized for higher communication data rates and therefore works without frequency
measurement during the write phase.
T_A
–40°C to 85°C
SOIC – D
ORDERING INFORMATION⁽¹⁾
PACKAGE ⁽²⁾
ORDERABLE PART NUMBER
Reel of 2500
TMS3705A1DRG4
TMS3705BDRG4
TOP-SIDE MARKING
TMS3705AG4
TMS3705BG4
(1) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI
web site at www.ti.com.
(2) Package drawings, thermal data, and symbolization are available at www.ti.com/packaging.
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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2010, Texas Instruments Incorporated