AK2358F Datasheet, PDF (22/26 Pages) Asahi Kasei Microsystems – Base-band LSI for Europian Cordless Telephones(CTI, CTI+)

ASAHI KASEI
[AK2358FI
I
Application Circuit Example
I
s Application Circuit
OAMP 1
Use as a transmitting microphone amplifier. The gain should be less than 30dB. _To
eliminate high frequency noise component over than 100kHz from input signal, Ist order
or 2nd order anti-aliasing filter is necessary. The following drawing is one example of
the 2nd order anti-aliasing filter, which has 30dB gain and 10kHz cut-off frequency.
A
AMP1
\/
.
J
TXINO
~3
f \)
TXINR2
cl
&
C1=2200PF
C2=33PF
Rl=R2=10k Q
R3-330k Q
<
LSI
@3moothing filter for MOD output signal
Realize low-pass filter to eliminate l12kHz clock signal component from MOD pin
output signal. The following is one example of the 1st order low-pass filter which has
8.7kHz cut-off frequency. 10kQ of the modulator load resistor(RL) provide 3.3dB signal
attenuation.
R
C2
MOD
-T
‘l_Tl ₌‘L
R=3.9k 52
cl=4700pF
CZ=OI~F
RL=lOk Q (Load resistance of MOD)
0AMP2
The amplifier for the receiving gain adjustment and anti-aliasing filtering to
eliminate high frequency noise component over 100kHz. The gain should be less than 30dB.
The following is an example of the 2nd order low pass filter, which has 20 dB gain and
40kHz cut-off frequency.
RXINO
C1=560PF
C2=27pF
Rl=lOkQ
AMP2
<
LSI
R2=9. lkQ
R3=100k Q
0152-E-00
- 21
1996, 12