AK4641 Datasheet, PDF (32/51 Pages) Asahi Kasei Microsystems – 16 BIT CODEC WITH BLUETOOTH INTERFACE

ASAHI KASEI
[AK4641]
„ 16bit Mono CODEC for Bluetooth I/F
The AK4641 has the 16bit Mono CODEC to connect with Bluetooth Module that supports 8kHz to 16kHz sample rate.
The AK4641 includes PLL that generate the master clock for Mono CODEC from input BSYNC signal. The PLL should
be powered-up after BSYNC signal is inputted. The PLL needs 90ms (max) lock time, when the PLL is powered-up
(PMBIF bit = “0” → “1”) and BSYNC is input. PMDA2 bit should be set to “0” or “0” data should be input to DAC of
Mono CODEC during 90ms after PMBIF bit is set to “1”.
BBICK and BSYNC should always be present when either ADC or DAC of Mono CODEC is power-up. If these clocks
are not provided, the AK4641 may draw excess current and it is not possible to operate properly because utilizes dynamic
refreshed logic internally. If BBICK or BSYNC is not present, ADC and DAC of Mono CODEC should be in the
power-down mode.
ADC
The ADC of Mono CODEC outputs the signal from DAC of Stereo CODEC, Mic In and AUX In. The ADC of Mono
CODEC enters an initialization cycle that starts when the PMAD2 bit is changed from “0” to “1”. The initialization cycle
time is 1057/Bfs, or 132ms@Bfs=8kHz. During the initialization cycle, the ADC digital data output of Mono CODEC are
forced to a 2's compliment, “0”. The ADC output of Mono CODEC reflects the analog input signal after the initialization
cycle is complete.
• ADC full Scale Level: 0.6*AVDD [Vpp](1.98Vpp@3.3V)
Full Scale level of ADC of Mono CODEC is the same as that of DAC of Stereo CODEC.
DAC of
Mono CODEC
Mic In
0dB/+20dB
IPGA
DAC2 bit
ATT
DACL bit
ATT +
Stereo DAC
MICL bit
AK4641
ADC2 bit _{ADC of}
Mono CODEC
AUX In
AUXL bit
Line Out
Bluetooth
Module
Bth Headset
External
HP-Amp
Headphone
Volume
Figure 30. Path to ADC of Mono CODEC
DAC
The signal that is output from DAC of Mono CODEC is sent to Line Out, Mono Out and ADC of Stereo CODEC.
• DAC full Scale Level: 0.6*AVDD [Vpp](1.98Vpp@3.3V)
Full Scale level of DAC of Mono CODEC is the same as that of ADC of Stereo CODEC.
Microphone
Bth Headset
Bluetooth
Module
AK4641
IPGA with ALC
Mic In
0dB/+20dB
DAC of
Mono CODEC
MICL bit
ATT
Line Out through stereo mixer
MICM bit
ATT
Mono Out
MICAD bit
DAC2 bit
ADC of Stereo
CODEC
µP
AUX In
Figure 31. Path from DAC of Mono CODEC
MS0301-E-00
- 32 -
2004/05