TDA5250D2_07 Datasheet, PDF (58/94 Pages) Infineon Technologies AG – ASK/FSK 868MHz Wireless Transceiver

TDA5250 D2
Version 1.7
Application
In the bipolar mode the FSK-switch can be controlled by a ramp function. This ramp function is set
by the bits D1 and D2 of the XTAL_CONFIG register (subadress 0EH). With these modes of the
FSK-switch the bandwidth of the FSK spectrum can be influenced.
When working in the FET mode the power consumption can be reduced by about 200 µA.
The default mode is bipolar switch with no ramp function (D0 = 1, D1 = D2 = 0), which is suitable
for all bitrates.
Table 3-3 Sub Address 0EH: XTAL_CONFIG
D0 D1 D2
Switch mode
0 n.a. n.a.
FET
1
0
0
bipolar (default)
1
1
0
bipolar
1
0
1
bipolar
1
1
1
bipolar
Ramp time
< 0.2 µs
< 0.2 µs
4 µs
8 µs
12 µs
Max. Bitrate
> 32 kBit/s NRZ
> 32 kBit/s NRZ
32 kBit/s NRZ
16 kBit/s NRZ
12 kBit/s NRZ
3.2.6 Finetuning and FSK modulation relevant registers
Case FSK-RX or ASK-TX (C_tune2):
Table 3-4
Bit
D5
D4
D3
D2
D1
D0
Sub Address 02H: XTAL_TUNING
Function
Value
Nominal_Frequ_5
8pF
Nominal_Frequ_4
4pF
Nominal_Frequ_3
2pF
Nominal_Frequ_2
1pF
Nominal_Frequ_1
500fF
Nominal_Frequ_0
250fF
Description
Setting for
nominal
frequency
ASK-TX
FSK-RX
(Ctune2)
Default
0
1
0
0
1
0
Case FSK-TX or ASK-RX (C_tune1 and C_tune2):
Table 3-5
Bit
D13
D12
D11
D10
D9
D8
Sub Address 01H: FSK
Function
FSK+5
FSK+4
FSK+3
FSK+2
FSK+1
FSK+0
Value
8pF
4pF
2pF
1pF
500fF
250fF
Description
Setting for
positive
frequency
shift: +FSK
or ASK-RX
(Ctune2)
Default
0
0
1
0
1
0
Data Sheet
58
2007-02-26