AKM AK4678 24位立体声CODEC解决方案

1、akm ak4678 24位立体声codec解决方案akm公司的ak4678是24位立体声codec,具有内置麦克风,接收放大器,单声道d类扬声器放大器,无的g类耳机放大器和线路放大器.除了音频i/f外还有两个pcm i/f.播放功能包括5波段参数eq和动态范围控制,因此能自动调节合适音量而不失真.本文介绍了ak4678主要特性,模拟和数字方框图,以及评估板 akd4678-b功能,方框图,和元件布局图.the ak4678 is a 24bit stereo codec with a built-in microphone-amplifier, receiver-amplifier, mon

2、o class-d speaker-amplifier, cap-less class-g headphone-amplifier and line-amplifier. the ak4678 features dual pcm i/f in addition to audio i/f that allows easy interfacing in mobile phone designs with bluetooth i/f. the playback features also include 5-band parametric eq and dynamic range control,

3、therefore the ak4678 can automatically adjust a comfortable volume without distortion and provides great flexibility. the ak4678 is available in a 49pin csp, utilizing less board space than competitive offerings.ak4678主要特性:1. recording function (stereo codec)4 stereo input selectors4 stereo inputs (

4、single-ended) or 3 mono input (full-differential)mic amplifier: +24db 6db, 3db step2 output mic power suppliesdigital alc (automatic level control): +36db 54db, 0.375db step, mutecharacteristics: s/(n+d): 80db, dr, s/n: 87db (mic-amp=+18db)s/(n+d): 80db, dr, s/n: 92db (mic-amp=0db)stereo digital mic

5、 interfacewind-noise reduction filterstereo separation emphasis3-band programmable notch filteraudio interface format: 24/16bit msb justified, 24/16bit i2s, 16bit mode 2. playback function (stereo codec)digital volume (+6db 57.0db, 0.5db step, mute)digital alc (automatic level control): +36db 54db,

6、0.375db step, mutestereo separation emphasisdynamic range control5-band parametric equalizerstereo line output (selectable full-differential / single-ended)mono receiver-amp- btl output- output power: 60mw 32- analog volume: +12 30db & mute, 3db stepcap-less stereo class-g headphone-amp- output

7、power: 25mw 32, 45mw 16- analog volume: +6 62db & mute, 2db step- zero crossing detection- pop noise free at power-on/offmono class-d speaker-amp- btl output- short protection circuit- output power: 1.1w 8, svdd=4.2v, thd+n = 10%0.89w 8, svdd=4.2v, thd+n = 1%- analog volume: +12 30db & mute,

8、 3db step- pop noise free at power-on/offaudio interface format:- 24/16bit msb justified, 16bit lsb justified, 16/24bit i2s, 16bit dsp mode3. dual pcm i/f for baseband & bluetooth interface four sample rate converters (up sample: up to x6: down sample: down to x1/6)sample rate:- porta (mono): 8

9、16khz- portb (stereo): 8 48khzdigital volumeslave modeaudio interface format:- 16bit , 8bit a-law, 8bit -law- short/long frame, i2s, msb justified4. power management5. master clock(audio i/f):(1) pll modefrequencies: 11.2896mhz, 12mhz, 12.288mhz, 13mhz, 13.5mhz, 19.2mhz, 24mhz, 25mhz, 26mhz, 27mhz (

10、mcki pin)32fs or 64fs (bick pin)(2) external clock modefrequencies: 256fs, 512fs or 1024fs (mcki pin)6. output master clock frequencies(audio i/f): 32fs/64fs/128fs/256fs7. sampling frequency (audio i/f)pll slave mode (bick pin): 8khz 48khzpll master mode:8khz, 11.025khz, 12khz, 16khz, 22.05khz, 24khz, 32khz, 44.1khz, 48khzext master/slave mode:8khz 48khz (256fs), 8khz 24khz (512fs), 8khz 12khz (1024fs)8. audio i/f: master/slave mode9. p i/f: i2c bus (ver 1.0, 400khz fast mode)10. ta = 30 85?c11. power supply:svdd (spk/rcv/line-amp): 3.0 5.5vavdd (analog)