ak4564 AKM Semiconductor, Inc., ak4564 Datasheet - Page 18

• Manufacturer Part Number: ak4564
• Description: 16bit Codec With Built-in Alc And Mic/hp/spk-amp
• Manufacturer: AKM Semiconductor, Inc.

ASAHI KASEI
n Analog Mixing Circuit for Recording Block
1. BEEP1 Input
2. LINE Input
3. MIX1-Amp
4. MIX2-Amp
MS0140-E-01
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
Input resistance of LIN1, RIN1, LIN2 and RIN2 are typically 100k 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”
MIX1-Amp is powered-up when ADC bit = “1” or MIX1P bit = “0”.
MIX2-Amp mixes Pre-Amp output and MIX1-Amp output at the ratio of “1:1”.
BEEP1
(RIN1)
(RIN2)
LIN1
LIN2
6.2k
6.2k
6.2k
6.2k
Ri
Figure 13. Analog Mixing Circuit for Recording Block
BEEP1Amp
typ.20k
-
+
typ.100k
typ.100k
typ.100k
From Pre-Amp
BEEP1
AIN1
AIN2
- 18 -
To Rch MIX1
typ.100k
-
+
MIX1
30% . (Refer to Figure 13)
AIN1, AIN2 or BEEP1
PRE
To HP-Amp
-
+
MIX2
To ADC
[AK4564]
2002/07