TDA5235
Functional Description
Single Config
run mode
RX polling
sleep mode
A
T
MasterPeriod = TAON + TOFF
T
AON
T
OFF
T
MasterPeriod
Multi Config
run mode
A
B
RX polling
sleep mode
T
MasterPeriod = TAON + TBON + TOFF
T
AON
TBON
T
OFF
T
MasterPeriod
Figure 80
Constant On-Off Time
Calculation of the On time:
The On time must be long enough to ensure proper detection of a specified wake-up
criterion. Therefore the On time depends on the wake-up pattern, and the wake-up
criterion. It has to include transmitter data rate tolerances.
A widely used wake-up pattern is a sequence of equal Bi-phase encoded bits or a certain
Bi-phase encoded bit pattern.
TON also must include the relevant start-up times. In case of the first configuration after
TOFF, this is the Receiver Start-Up Time. In case of the following Configuration B (RF
Receiver is already on, there is only a change of the configuration), e.g. if Configuration
B is used, this is the Configuration Change Latency Time. In addition, it has to be
considered that some data bits are required for synchronization and internal latency, see
Chapter 2.4.8.8 RUNIN, Synchronization Search Time and Inter-Frame Time.
There are other wake-up patterns in use as well, which have several (up to 10 and more)
short wake-up sequences (a few byte each) that are separated by a certain pause (again
a few byte each). In this case the On time has to be set, so that a possible wake-up can
be found within two wake-up sequences including the pause in-between.
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
Data Sheet
114
V1.0, 2010-02-19
INFINEON [ Infineon ]
