TDA5225 Datasheet, PDF (69/176 Pages) Infineon Technologies AG – Enhanced Sensitivity Multi-Channel Quad-Configuration Receiver

TDA5225
Functional Description
Single Channel, Single Config
run mode
RX polling
A
1
sleep mode
TAON
TOFF
TMasterPeriod
Multi Channel, Single Config
run mode
RX polling
A
1
A
2
A
3
sleep mode
TAON TAON TAON
TOFF
TMasterPeriod
Multi Channel, Multi Config
run mode
RX polling
A
1
A
2
A
3
sleep mode
TAON TAON TAON
B
1
TBON
B
2
TBON
TMasterPeriod
TOFF
Figure 45 Constant On-Off Time
Channels = 1
TMasterPeriod = TAON + TOFF
Channels = m
TMasterPeriod = m*TAON + TOFF
Channels Config A = m
Channels Config B = n
TMasterPeriod = m*TAON + n*T BON+ TOFF
Calculation of the On time:
The On time for each channel must be long enough to ensure proper detection of a
specified wake-up criterion. Therefore the On time depends on the wake-up pattern. It
has to include transmitter data rate tolerances.
T_ON also must include the relevant start-up times. In case of the first channel after T_OFF,
this is the Receiver Start-Up Time. In case of following channels (RF Receiver is already
on, there is only a change of the channel or the configuration), e.g. if Configuration B is
used, this is the Channel Hop Latency Time.
Calculation of the Off time:
The longer the Off time, the lower the average power consumption in Self Polling Mode.
On the other hand, the Off time has to be short enough that no transmitted wake-up
pattern is missed. Therefore the Off time depends mainly on the duration of the expected
wake-up pattern.
If there are further channels scanned, T_OFF has to be reduced by the related additional
On times.
Data Sheet
69
V1.0, 2010-02-19