AK2346B Datasheet, PDF (27/31 Pages) Asahi Kasei Microsystems – Two-way Radio Audio Processor

ASAHI KASEI
[AK2346B]
4) RXA2 Amplifier
This is an operational amplifier suitable for receive gain adjuster and smoothing filter to eliminate
461kHz sampling clock component included in EXPOUT pin. The following simplified schematic
shows an example of 1^st order Low-pass filter that has 0dB gain and 19kHz cut-off frequency.
18 EXPOUT
C1
19 ^RXAFIN
R1
C1=0.022uF
C2=150pF
_
C2
R2
+
20 ^RXAF
R1=R2=56kΩ
RXA2
LSI
5) Power supply stabilizing capacitors
To connect capacitors between VDD and VSS pin reduce the ripple and noise included in power
supply. These capacitors are mounted close to the device pins.
17 VDD
VDD
C1
8 VSS
C2
VSS
C1=22uF (Electrolytic cap)
C2=0.1uF (Ceramic cap)
LSI
6) AGND, AGNDIN pin stabilizing
Please decouple to VSS level by the 0.3uF or larger capacitor. These capacitors are mounted
close to the device pins.
1 AGNDIN
2 AGND
C
C
C=1uF
MS1409-E-00
LSI
- 27 -
2012/05