TDA5225 Datasheet, PDF (68/176 Pages) Infineon Technologies AG – Enhanced Sensitivity Multi-Channel Quad-Configuration Receiver

TDA5225
Functional Description
2.6.2.1 Self Polling Mode
An actual value for RSSI exceeding a certain adjustable threshold forces the TDA5225
into Run Mode Self Polling.
The timing resolution is defined by the Reference Timer, which scales the incoming
frequency (f_sys/64) corresponding to the value, which is defined in the Self Polling Mode
Reference Timer (SPMRT) register. Changing values of SPMRT helps to fit the final On-
Off timing to the calculated ideal timing.
2.6.2.2 Constant On-Off Time (COO)
In this mode there is a constant On and a constant Off time. Therefore also the resulting
master period time is constant. The On and Off time are set in the SPMONTA0,
SPMONTA1, SPMONTB0, SPMONTB1, SPMONTC0, SPMONTC1, SPMONTD0,
SPMONTD1, SPMOFFT0 and SPMOFFT1 registers. The On time configuration is done
separately for Configuration A, B, C and D.
When Single-Configuration is selected then only Configuration A is used. The number
of RF channels is defined in the A_CHCFG register (Single-Channel or Multi-Channel
Mode).
Multi-Configuration Mode allows reception of up to 4 different transmit sources. The
corresponding RF channels can be defined in the A_CHCFG, B_CHCFG, C_CHCFG
and D_CHCFG registers. In the case of Multi-Channel or combination of Multi-Channel
and Multi-Configuration Mode, the configured On time is used for each RF channel in a
configuration. The diagram below shows possible scenarios.
All receive modes described in Chapter 2.5.1.2 Data Interface can be used.
Data Sheet
68
V1.0, 2010-02-19