TDA7210V_10 Datasheet, PDF (22/44 Pages) Infineon Technologies AG – ASK/FSK Single Conversion Receiver

TDA7210V
Applications
3.5
Data Slicer Threshold Generation
The threshold of the data slicer, especially for a coding scheme without DC-content, can be generated using an
external R-C integrator as shown in Figure 9. The time constant TA of the R-C integrator has to be significantly
larger than the longest period of no signal change TL within the data sequence. For the calculation of the time
constant TA please see Application Note „TDA521x_ANV1.1“, chapter „4.11 Data Slicer“. In order to keep
distortion low, the minimum value for R1 is 20 kΩ.
R1
C13
Pins: 18
data
filter
19
U_threshold
data out
25
data slicer
Figure 9 Data Slicer Threshold Generation with External R-C Integrator
In case of ASK operation another possibility for threshold generation is to use the peak detector in connection with
two resistors and one capacitor as shown in the following figure. The component values are depending on the
coding scheme and the protocol used.
R3
C15
R2
Pins: _{26 18 19}
peak detector
U_threshold
data out
25
data slicer
data
filter
Figure 10 Data Slicer Threshold Generation Utilising the Peak Detector
Data Sheet
22
Revision 1.1, 2010-06-18