[AK4955]
AK4955
24bit Stereo CODEC with MIC/SPK/Cap-less VIDEO-AMP/ LDO & DSP
GENERAL DESCRIPTION
The AK4955 is a 24bit stereo CODEC with a microphone amplifier, speaker amplifier, video amplifier,
LDO, and DSP. The input circuits include a microphone amplifier and the output circuits include a speaker
amplifier. It is suitable for portable application with recording/playback function. A one channel composite
In/Out video amplifier is also integrated. The internal charge pump generates a negative power
eliminating the need for AC-coupling capacitors. The AK4955 is available in a small 36pin CSP (3.0mm x
3.1mm, 0.5mm pitch), saving mounting area on the board.
FEATURES
1. Recording Functions
•
Stereo Single-ended input with two Selectors
•
MIC Amplifier (+24dB/+21dB/+18dB/+16dB/+14dB/+11dB/+8dB/+5dB/0dB)
•
Digital ALC (Automatic Level Control)
(Setting Range: +36dB
∼ −54dB,
0.375dB Step)
•
ADC Performance: S/(N+D): 81dB, DR, S/N: 88dB (MIC-Amp=+18dB)
S/(N+D): 82dB, DR, S/N: 96dB (MIC-Amp=0dB)
•
Microphone Sensitivity Compensation
•
5 Band Notch Filter
•
Stereo Separation Emphasis Circuit
•
Digital MIC Interface
2. Playback Functions
•
Digital De-emphasis Filter (tc=50/15µs, fs=32kHz, 44.1kHz, 48kHz)
•
Soft Mute
•
Digital ALC (Automatic Level Control)
- Setting Range: +36dB ~
−54dB,
0.375dB Step
•
Digital Volume Control (+12dB ~
−115dB,
0.5dB Step & Mute)
•
Stereo Separation Emphasis Circuit
•
Stereo Line Output
- Output Voltage: +2dBV(1.26Vrms) (LVDD= 4.8V)
2.52Vpp (LVDD=3.3V)
- S/(N+D): 85dB, S/N: 92dB
•
Mono Mixing Output
•
Mono Speaker-Amplifier
- S/(N+D): 70dB@150mW, 60dB@250mW,
- S/N: 95dB
- BTL Output
- Output Power: 600mW@8Ω (SVDD=4.8V)
400mW@8Ω (SVDD=3.3V)
•
Analog Mixing: Mono Input
•
Beep Generator
MS1343-E-00
-1-
2011/12
AKM [ ASAHI KASEI MICROSYSTEMS ]
