
[AK4671] 
MS0666-E-00 
2007/10 
- 1 - 
GENERAL DESCRIPTION 
The AK4671 is a stereo CODEC with a built-in Microphone-Amplifier, Receiver-Amplifier and 
Headphone-Amplifier. The AK4671 features dual PCM I/F in addition to audio I/F that allows easy 
interfacing in mobile phone designs with Bluetooth I/F. The AK4671 is available in a 57pin BGA, utilizing 
less board space than competitive offerings. 
FEATURES 
1. Recording Function (Stereo CODEC) 
 4 Stereo Input Selector x 2ch 
 4 Stereo Inputs (Single-ended) or 2 Stereo Input (Full-differential) 
 MIC Amplifier: +30dB 
~
12dB, 3dB step 
Digital ALC (Automatic Level Control): +36dB 
~
54dB, 0.375dB Step, Mute 
 Wind-noise Reduction Filter 
 Stereo Separation Emphasis 
 5-band Programmable Notch Filter 
 Audio Interface Format: 16bit MSB justified, I
2
S, DSP Mode 
2. Playback Function (Stereo CODEC) 
 Digital Volume (+12dB 
~
115.0dB, 0.5dB Step, Mute) 
Digital ALC (Automatic Level Control): +36dB 
~
54dB, 0.375dB Step, Mute 
 Stereo Separation Emphasis 
 5-band EQ 
 Stereo Line Output
 Mono Receiver-Amp
- BTL Output
- Output Power: 30mW@32
Ω
 (AVDD=3.3V) 
 Stereo Headphone-Amp
- Output Power: 30mW@16
Ω
 (AVDD=3.3V) 
 Analog Mixing: 4 Stereo Input 
 Audio Interface Format: 
- 16bit MSB justified, 16bit LSB justified, 16-24bit I
2
S, DSP Mode 
3. Dual PCM I/F for Baseband & Bluetooth Interface 
Sample Rate Converter (Up sample: up to x6: Down sample: down to x1/6) 
Sample Rate: 8kHz 
Digital Volume 
Audio Interface Format: 
- 16bit Linear, 8bit A-law, 8bit 
μ
-law 
- Short/Long Frame, I
2
S, MSB justified 
4. 10bit SAR ADC 
3 Input Selector 
5. Power Management 
6. Master Clock: 
(1) PLL Mode
 Frequencies: 11.2896MHz, 12MHz, 12.288MHz, 13MHz, 13.5MHz, 19.2MHz, 
24MHz, 26MHz, 27MHz (MCKI pin) 
1fs (LRCK pin) 
32fs or 64fs (BICK pin) 
(2) External Clock Mode
 Frequencies: 256fs, 384fs, 512fs, 768fs or 1024fs (MCKI pin) 
7. Output Master Clock Frequencies: 32fs/64fs/128fs/256fs 
8. Sampling Rate (Stereo CODEC): 
Stereo CODEC with MIC/RCV/HP-AMP 
AK4671