TDA5225 Datasheet, PDF (60/176 Pages) Infineon Technologies AG – Enhanced Sensitivity Multi-Channel Quad-Configuration Receiver

TDA5225
Functional Description
In case of large frequency steps, an additional VAC routine (VCO Automatic Calibration)
has to be activated when recovering from HOLD Mode (INITPLLHOLD bit). The
maximum allowed frequency step in HOLD Mode without activation of VAC routine is
depending on the selected frequency band. The limits are +/- 1 MHz for the 315 MHz
band, +/- 1.5 MHz for the 434 MHz band and +/- 3 MHz for the 868/915 MHz band.
When this additional VAC routine is enabled, the TDA5225 starts initialization of the
Digital Receiver block after release from HOLD and an additional Channel Hop time.
FSM State Data available at Port Pin
Instruction Address Data Instruction Address Data
SPI Command ^Write
CMC0 HOLD=1 Write x_CHCFG/ (sel. other
0x02
0x02 x_PLL.. channel)
HOLD
VAC
VAC
Instruction Address Data
Write
CMC0 HOLD=0
0x02
12us @ 2.0MHz
40us
t C_ Hop
Data
INIT available at
Port Pin
Figure 39 HOLD State Behavior (INITPLLHOLD enabled)
HOLD Mode is only available in Run Mode Slave. Configuration changes in Self Polling
Mode have to be done by switching to SLEEP Mode and returning to Self Polling Mode
after reconfiguration.
2.6.1.4 SLEEP Mode
The SLEEP Mode is a power save mode. The complete RF part is switched off and the
oscillator is in Low Power Mode. As in HOLD Mode, the chip can be reconfigured. When
switching from SLEEP to Run Mode Slave, the state machine starts with the internal
Start-Up Sequence.
2.6.1.5 Self Polling Mode (SPM)
In Self Polling Mode TDA5225 autonomously polls for incoming RF wake-up data
streams. At that time there is no processing load on the host microcontroller. When a
wake-up criterion has been found, an interrupt can be generated and the TDA5225 mode
will be changed to Run Mode Self Polling.
A general overview on a typically transmitted protocol and the behaviour of the TDA5225
is given in Figure 40.
Data Sheet
60
V1.0, 2010-02-19