SLRC400 Datasheet, PDF (84/130 Pages) NXP Semiconductors – I·CODE Reader IC

Philips Semiconductors
I•CODE Reader IC
Product Specification Rev. 2.0 November 2001
SL RC400
13 TRANSMITTER PINS TX1 AND TX2
The signal delivered on TX1 and TX2 is the 13.56 MHz carrier frequency modulated by an envelope signal. It
can be used to drive an antenna directly, using a few passive components for matching and filtering (see
chapter 17). For that, the output circuitry is designed with an very low impedance source resistance. The
signal of TX1 and TX2 can be controlled via the TxControl Register.
13.1 Configuration of TX1 and TX2
The configuration possibilities of TX1 are described in the table below:
Register Configuration in TxControl
TX1RFEn
0
1
1
Envelope
X
0
1
Signal on TX1
LOW (GND)
13.56 MHz carrier frequenzy modulated
13.56 MHz carrier frequenzy
Table 13-1: Configurations of Pin TX1
The configuration possibilities of TX2 are described in the table below:
Register Configuration in TxControl
TX2RFEn
TX2CW
InvTX2
0
X
X
0
0
1
1
Envelope
X
0
1
0
1
Signal on TX2
LOW (GND)
13.56 MHz carrier frequenzy modulated
13.56 MHz carrier frequenzy
13.56 MHz carrier frequenzy modulated,
180° phase shift relative to TX1
13.56 MHz carrier frequenzy,
180° phase shift relative to TX1
0
1
1
X
13.56 MHz carrier frequenzy
X
13.56 MHz carrier frequenzy,
180° phase shift relative to TX1
Table 13-2: Configurations of Pin TX2
13.2 Operating Distance versus Power Consumption
The user has the possibility to find a trade-off between maximum achievable operating distance and power
consumption by using different antenna matching circuits as described in 17.3.1 and/or by varying the supply
voltage at the antenna driver supply pin TVDD.
84
Preliminary