AK4564 Datasheet, PDF (18/48 Pages) Asahi Kasei Microsystems – 16BIT CODEC WITH BUILT-IN ALC AND MIC/HP/SPK-AMP

ASAHI KASEI
[AK4564]
n Analog Mixing Circuit for Recording Block
Ri
BEEP1
LIN1
(RIN1)
6.2kΩ
6.2kΩ
LIN2
(RIN2)
6.2kΩ
6.2kΩ
typ.20kΩ
-
+
BEEP1Amp
typ.100kΩ
BEEP1
typ.100kΩ
AIN1
To Rch MIX1
typ.100kΩ
-
+
typ.100kΩ
MIX1
AIN2
From Pre-Amp
AIN1, AIN2 or BEEP1
-
+
PRE
MIX2
To HP-Amp
To ADC
Figure 13. Analog Mixing Circuit for Recording Block
1. BEEP1 Input
When BEEP1 bit is “1”, the input signal via BEEP1 pin can be applied to ADC. This signal level can be adjusted by an
external resistor (Ri). Feed-back resistor of BEEP1-Amp is 20k ± 30% Ω. (Refer to Figure 13)
2. LINE Input
Input resistance of LIN1, RIN1, LIN2 and RIN2 are typically 100kΩ and centered around the VCOM voltage. When
the input voltage exceeds +2dBV, the input signals should be attenuated down to –4.3dBV at VA=2.8V by external
resistor divider.
When AIN1 bit is “1”, LIN1 and RIN1 pins are selected. When AIN2 bit is “1”, LIN2 and RIN2 pins are selected. If
AIN1 and AIN2 bits are selected at the both input signals are mixed by the ratio of “1:1”
3. MIX1-Amp
MIX1-Amp is powered-up when ADC bit = “1” or MIX1P bit = “0”.
4. MIX2-Amp
MIX2-Amp mixes Pre-Amp output and MIX1-Amp output at the ratio of “1:1”.
MS0140-E-01
- 18 -
2002/07