參數(shù)資料
型號: TDA5220
廠商: INFINEON TECHNOLOGIES AG
英文描述: ASK/FSK Single Conversion Receiver
中文描述: 詢價/ FSK信號單一轉(zhuǎn)換接收器
文件頁數(shù): 29/44頁
文件大?。?/td> 719K
代理商: TDA5220
Applications
4 - 9
TDA 5220
preliminary
Wireless Components
confidential
Target Specification, October 2001
4.6.1
FSK Mode
The FSK datapath has a bandpass characterisitc due to the feedback shown
above (highpass) and the data filter (lowpass). The lower cutoff frequency f2 is
determined by the external RC-combination. The upper cutoff frequency f3 is
determined by the data filter bandwidth.
The demodulation gain of the FSK PLL demodulator is 180μV/kHz. This gain is
increased by the gain v of the FSK switch, which is 11. Therefore the resulting
dynamic gain of this circuit is 2mV/kHz within the bandpass. The gain for the DC
content of FSK signal remains at 180μV/kHz. The cutoff frequencies of the
bandpass have to be chosen such that the spectrum of the data signal is influ-
enced in an acceptable amount.
In case that the user data is containing long sequences of logical zeroes the
effect of the drift-off of the bit slicer threshold voltage can be lowered if the offset
voltage inherent at the negative input of the slicer comparator (Pin20) is used.
The comparator has no hysteresis built in.
This offset voltage is generated by the bias current of the negative input of the
comparator (i.e. 20nA) running over the external resistor R. This voltage raises
the voltage appearing at pin 20 (e.g. 1mV with R = 100k
). In order to obtain
benefit of this asymmetrical offset for the demodulation of long zeros the lower
of the two FSK frequencies should be chosen in the transmitter as the zero-
symbol frequency.
In the following figure the shape of the above mentioned bandpass is shown.
frequenzgang.WMF
Figure 4-8
Frequency characterstic in case of FSK mode
The cutoff frequencies are calculated with the following formulas:
v
0dB
3dB
v-3dB
f
20dB/dec
-40dB/dec
f1
f2
f3
gain (pin19)
DC
0.18mV/kHz
2mV/kHz
C
k
R
k
R
f
+
=
330
330
2
1
1
π
相關(guān)PDF資料
PDF描述
TDA5221 ASK/FSK Single Conversion Receiver
TDA5250 ASK/FSK 868MHz Wireless Transceiver
TDA5250D2 ASK/FSK 868MHz Wireless Transceiver
TDA5251F1 ASK/FSK 315MHz Wireless Transceiver
TDA8050A QPSK transmitter
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TDA5220T 制造商:Infineon Technologies AG 功能描述:RKE RX RECIEVER, TSSOP-28, 3K
TDA5220XUMA1 制造商:Infineon Technologies AG 功能描述:RF Receiver ASK/FSK 5V T/R 制造商:Infineon Technologies AG 功能描述:CONTROL - Tape and Reel 制造商:Infineon Technologies AG 功能描述:RECEIVER SHR FSK/ASK SGL TSSOP28
TDA5221 功能描述:射頻接收器 ASK/FSK SNGL Convrsn Receiver RoHS:否 制造商:Skyworks Solutions, Inc. 類型:GPS Receiver 封裝 / 箱體:QFN-24 工作頻率:4.092 MHz 工作電源電壓:3.3 V 封裝:Reel
TDA5221INCT-ND 制造商:Infineon Technologies AG 功能描述:
TDA5221XUMA1 制造商:Infineon Technologies AG 功能描述:RF Receiver ASK/FSK 5V T/R 制造商:Infineon Technologies AG 功能描述:CONTROL - Tape and Reel 制造商:Infineon Technologies AG 功能描述:RECEIVER SHR FSK/ASK SGL TSSOP28