TDA5252G2 Datasheet, PDF (67/86 Pages) Infineon Technologies AG – ASK/FSK 915MHz Wireless Transceiver

Figure 3-30 Window Counter timing
Example to calculate the thresholds for a given data rate:
- Data signal manchester coded
- Data Rate: 2kbit//s
- f_clk= 19.0625 MHz
Then the period equals to
2 ⋅ T = ¹ = 0,5ms
2kbit/s
[3 – 36]
respectively the high time is 0,25ms.
We set the thresholds to +-10% and get: T1= 0,225ms and T2= 0,275ms
The thresholds TH1 and TH2 are calculated with following formulas
TH1 = T1⋅ ^fclk
4
[3 – 37]
TDA5252 G2
Version 1.1
Application
window_count_timing.wmf
TH2 = T2 ⋅ ^fclk
4
[3 – 38]
This yields the following results:
TH1~ 1072 = 010000110000_b
TH2~ 1310 = 010100011110_b
which have to be programmed into the D0 to D11 bits of the COUNT_TH1 and COUNT_TH2
registers (subaddresses 06H and 07H), respectively.
Default values (window counter inactive):
TH1= 000000000000_b
TH2= 000000000001_b
Note: The timing window of +-10% of a given high time T in general does not correspond to a
frequency window +-10% of the calculated data frequency.
3.7.2 RSSI threshold voltage - RF input power
The RF input power level is corresponding to a certain RSSI voltage, which can be seen in Section
3.5. The threshold TH3 of this RSSI voltage can be calculated with the following formula:
Data Sheet
67
2007-02-26