TDA5230 Datasheet, PDF (67/186 Pages) Infineon Technologies AG – Universal Low Power ASK/FSK Single Conversion Multi-Channel Image-Reject Receiver

TDA523x
Functional Description
Selection of IF Attenuation
Use always minimum IF Attenuation (0dB). Only if there is an external LNA used, IF
Attenuation should be set to the gain of the external LNA. If there is one or more SAW
filters, the insertion loss should be reduced from the external LNA gain.
If strong out of band disturbers are expected, an increase of IF Attenuation may increase
large signal immunity, at the cost of slight reduction in sensitivity.
RFC: RF Control Register
ADDR: 0x12
Reset Value: 0x00
Bit R/W Description
4 W RFOFF: Switch off RF path (for RSSI trimming)
0: RF path enabled
1: RF path off
3:0 W IFATT: Adjust IF attenuation in 16 steps to trim the gain RFIN --> IF-OUT
0000: 0 dB attenuation
1111: 12 dB attenuation
LOC: Local Oscillator Control Register
ADDR: 0x16
Reset Value: 0x00
Bit R/W Description
7:5 W Always set to 0
4 W SSBSEL: Local Oscillator Injection Mode Selection
0: Lo-Side LO Injection .. use for TDA5230
1: Hi-Side LO Injection .. use for TDA5231
3:0 W Always set to 0
2.4.7.1 RX-RUN/RXD Pin
The receiver enable signal is offered at the dedicated RX-RUN/RXD Pin to control
external components such as an external LNA. Whenever the receiver is active, the RX-
RUN output is high.
Note that the same output pin may be also configured to provide the received data in
Transparent Mode.
Data Sheet
63
Version 4.0, 2007-06-01