TDA5252G2 Datasheet, PDF (68/86 Pages) Infineon Technologies AG – ASK/FSK 915MHz Wireless Transceiver

TDA5252 G2
Version 1.1
Application
TH3 = ^desired
RSSI threshold
1.2V
voltage _{⋅ ( 2 6 − 1 )}
[3 – 39]
As an example a desired RSSI threshold voltage of 500mV results in TH3~26=011010b, which has
to be written into D0 to D5 of the RSSI_TH3 register (sub address 08H).
Default value (RSSI detection inactive):
TH3=111111b
3.8
Calculation of ON_TIME and OFF_TIME
ON= (2¹⁶-1)-(f_RC*t_ON)
OFF=( 2¹⁶-1)-(f_RC*t_OFF)
f_RC= Frequency of internal RC Oszillator
[3 – 40]
[3 – 41]
Example: t_ON= 0,005s, t_OFF= 0,055s, f_RC= 32300Hz
ON= 65535-(32300*0,005) ~ 65373= 1111111101011101_b
OFF= 65535-(32300*0,055) ~ 63758= 1111100100001110_b
The values have to be written into the D0 to D15 bits of the ON_TIME and OFF_TIME registers
(subaddresses 04H and 05H).
Default values:
ON= 65215 = 1111111011000000_b
OFF= 62335 = 1111001110000000_b
t_ON ~10ms @ f_RC= 32kHz
t_OFF ~100ms @ f_RC= 32kHz
3.9
Example for Self Polling Mode
The settings for Self Polling Mode depend very much on the timing of the transmitted Signal. To
create an example we consider following data structure transmitted in FSK.
Data Sheet
68
2007-02-26