TMS3705A1DRG4 (TEXAS INSTRUMENTS)

The TMS3705A1DRG4 is a Transponder Base Station IC 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 (134.2kHz for low bits and 123kHz 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. Microcontroller and base station IC are supplied with a clock signal derived from only one resonator.