TDA5250D2 Datasheet, PDF (84/97 Pages) Infineon Technologies AG – ASK/FSK 868MHz Wireless Transceiver

confidential
TDA 5250 D2
preliminary
Applications
4.10.5 Sensitivity at Frequency Offset
Applying the test setup in Figure 4-36 even a wide offset in the received
frequency spectrum results only in a slight decrease of receiving sensitivity. At
an offset of 100kHz one of the two 50kHz FSK peaks is at the 3dB border of the
IQ filter (150kHz), which is the reason for the decline of the sensitivity (see point
A in Figure 4-40).
A frequency offset of 50kHz (FSK deviation: 50kHz) increases the data jitter of
the demodulated signal and therefore results in little loss of sensitivity (see point
B in Figure 4-40).
In this case one of the peaks of the FSK-spectrum lies in the DC-blocking notch
of the baseband limiters.
Figure 4-40 BER Frequency Offset
BER_FrequOffset_FSK_3V..wmf
Wireless Components
4 - 44
Specification, July 2002