AK2363 Datasheet, PDF (29/33 Pages) Asahi Kasei Microsystems – Radio Signaling LSI

ASAHI KASEI
[AK2363]
Recommended External Circuit Examples
1) TXA amplifier
This amplifier is used to adjust the gain of the TX signal and to form a smoothing filter.
Because the MSKOUT pin output includes a 115.2kHz sampling clock, it is recommended that this
amplifier be used for smoothing.
The following gives a sample configuration of a first order LPF with a gain of 0dB and cut-off frequency
of 13kHz:
24 MSKOUT
23 ^MODIN
R1
C=220pF
_
C
R2
+
22 ^MOD
R1=R2=56kW
TXA
LSI
2) RXA amplifier
This amplifier is used for adjusting the gain of the RX signal. Set the gain to 20dB or less. For high
frequency noise over 100kHz, form an anti-aliasing filter.
The following gives a sample configuration of a second order LPF with a gain of 20dB and cut-off
frequency of 39kHz:
_
+
RXA
19 RXINO
C2
20 RXIN _R2
21 _AGND
R3
R1 C1
C3
LSI
C1=0.47mF
C2=33pF
C3=560pF
R1=10kW
R2=9.1kW
R3=100kW
MS0583-E-01
- 29 -
2008/06