AK2305 Datasheet, PDF (40/43 Pages) Asahi Kasei Microsystems – Dual PCM CODEC for ISDN TERMINAL ADAPTER

ASAHI KASEI
[AK2305]
DTIN0, DTIN1 INPUT
There are the following 2 cases in case of that DTMF tone is input through DTIN0,DTIN1.
(1)DTMF tone is output from AMPT0,AMPT1 included AK2305
Connect GSXn with DTINn directly.
AK2305
GSXn
DTINn
(2) DTMF tone is output from an external amplifier
DTMF tone is input to DTIN0,DTIN1 through an external capacitance of more than 0.1uF.
AK2305
C
DTIN0
DTIN1
Analog ground stabilization capacitor
An external capacitor of more than 0.1uF should be connected between VREF and AVSS to stabilize
analog ground (VREF).
AK2305
VREF
+C
PLL Loop filter capcitor
An external capacitor of more than 0.22uF should be connected between LPC and AVSS.
AK2305
LPC
+C
C0029-E-02
40
1999/8