AK4687 AKM [Asahi Kasei Microsystems], AK4687 Datasheet - Page 20

• Manufacturer Part Number: AK4687
• Description: Asynchronous Stereo CODEC with Capless Stereo Selector
• Manufacturer: AKM [Asahi Kasei Microsystems]

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The internal charge pump circuit generates negative voltage (CVEE) from CVDD voltage for analog input and output.
The power up time of charge pump circuit is 1.3ms@48kHz. When PWAD and PWDA bits = “1”, the ADC and DAC are
powered-up after the charge pump circuit is powered-up.
The power-up conditions of the charge pump circuit are:
I
H/W Control Mode
Note: Connect a 1µF low ESR capacitor between CP and CN pins, and VSS3-VEE pins respectively.
MS1307-E-00
2
C Control Mode
• PDN1 pin = “H”, PWAD bit = “1” and MCLK1, LRCK1 and BICK1 (MCLK1 only in master mode) are input.
• PDN2 pin = “H”, PWDA bit = “1” and MCLK2, LRCK2 and BICK2 are input.
• PDN1 pin = “H” and MCLK1, LRCK1 and BICK1 (MCK1 only in master mode) are input.
• PDN2 pin = “H” and MCLK2, LRCK2 and BICK2 are input.
Charge Pump Circuit
PDN1
pin
H
x
PDN1
pin
H
x
PWAD
bit
1
x
Master mode: MCLK1
Slave mode: MCLK1, LRCK1, BICK1
Master mode: MCLK1
Slave mode:
MCLK1,LRCK1, BICK1
Table 23. Charge Pump Power ON Conditions (H/W Control Mode)
Table 22. Charge Pump Power ON Conditions (I
DVDD
active
Active
x
AK4687
x
CP
Figure 8. Charge Pump Circuit
Charge
(+)
1uF
Pump
CN
Ca
PDN2
pin
VSS3
H
x
- 20 -
PDN2
pin
H
x
Cb
PWDA
(+)
bit
x
1
MCLK2, BICK2, LRCK2
1uF
VEE
2
MCLK2, BICK2, LRCK2
C Control Mode)
Negative Power
active
x
active
x
(×: Don’t Care)
CP status
(×: Don’t Care)
ON
ON
CP status
ON
ON
[AK4687]
2011/05