CLRC632 Datasheet, PDF (99/163 Pages) NXP Semiconductors – Multiple Protocol Contactless Reader IC

Philips Semiconductors
Product Specification Rev. 3.0; May 2003
Multiple Protocol Contactless Reader IC
CL RC632
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 using different antenna matching circuits by varying the supply voltage at the antenna driver
supply pin TVDD. Different antenna matching circuits are described in the Application Note, MIFARE^
Design of MF RC500 Matching Circuit and Antennas.
13.3 Antenna Driver Output Source Resistance
The output source conductance of TX1 and TX2 for driving a HIGH level may be adjusted via the value
GsCfgCW in the CwConductance Register in the range from about 1 up to 100 Ohm. The output source
conductance of Tx1 and TX2 during the modulation phase may be adjusted via the value GsCfgMod in the
ModConductance Register in the same range. The values given are relative to the reference resistance Rs_rel,
that is measured during production test and stored in the CL RC632 E²PROM. It can be obtained from the
Product Information Field (see chapter 6.2). The electrical specification can be found in chapter 22.4.3.
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