TDA5250D2 Datasheet, PDF (73/97 Pages) Infineon Technologies AG – ASK/FSK 868MHz Wireless Transceiver

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TDA 5250 D2
preliminary
Applications
Timing in Single Shot mode can be seen in the subsequent figure:
Data
Sequenzer enables
t
data detection
t
Counter Reset
reset
t
Gate time
count
Compare with single
t
TH and latch result
comp.
Compare with double
t
TH and latch result
comp.
(Frequency) Window
Count Complete
t
ready*
start of conversion
no possible start of next conversion
because of Single Shot Mode
t
Figure 4-32
Frequency Detection timing in Single Shot mode
Frequ_Detect_Timing_singleShot_wmf
4.7.1 Frequency Window for Data Rate Detection
The high time of data is used to measure the frequency of the data signal. For
Manchester coding either the data frequency or half of the data frequency have
to be detected corresponding to one high time or twice the high time of data
signal.
A time period of 3*2*T is necessary to decide about valid or invalid data.
T
2*T
DATA
0
0
1
T2
T1
possible
GATE 1
0
2*T2
2*T1
possible
GATE 2
0
1
t
0
t
t
Figure 4-33 Window Counter timing
window_count_timing.wmf
Wireless Components
4 - 33
Specification, July 2002