Low Power 24-Bit 2ch ADC & 2ch DAC with ALC/Eq and Mic/SPK/Video-Amp

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The AK4957 is a 24bit stereo CODEC with a microphone, speaker, video amplifiers and LDO. 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 AK4957 is available in a small 32pin QFN (4mm x 4mm, 0.4mm pitch), saving mounting area on the board.

Key Features

1. Recording Functions

• Stereo Single-ended input with two Selectors

• MIC Amplifier (+21dB/+18dB/+16dB/+14dB/+8dB/0dB)

• Digital ALC (Automatic Level Control)

(Setting Range: +36dB to -54dB, 0.375dB Step)

• ADC Performance: S/(N+D): 83dB, DR, S/N: 88dB (MIC-Amp=+18dB)

S/(N+D): 85dB, DR, S/N: 96dB (MIC-Amp=0dB)

• Microphone Sensitivity Compensation

• 5 Band Notch Filter

• Stereo Separation Emphasis Circuit

• Digital MIC Interface

2. Playback Functions

• Soft Mute

• Digital ALC (Automatic Level Control)

(Setting Range: +36dB to -54dB, 0.375dB Step)

• Digital Volume Control (+12dB to -115dB, 0.5dB Step & Mute)

• Stereo Separation Emphasis Circuit

• Stereo Line Output

- Output Voltage: 1Vrms (AVDD= 3.3V)

- S/(N+D): 85dB

- S/N: 92dB

• Mono Mixing Output

• Mono Speaker-Amplifier

- S/(N+D): 65dB@150mW, 60dB@250mW,

- S/N: 90dB

- BTL Output

- Output Power: 400mW@8Ω (AVDD=3.3V)

• Analog Mixing: BEEP Input

3. Master Clock:

(1) PLL Mode

• Frequencies: 11.2896MHz, 12MHz, 13.5MHz, 24MHz, 27MHz (MCKI pin)

32fs or 64fs (BICK pin)

(2) External Clock Mode

• Frequencies: 256fs, 512fs or 1024fs (MCKI pin)

Output Master Clock Frequency: 32fs/64fs/128fs/256fs

4. Sampling Frequencies

• PLL Slave Mode (MCKI pin):

8kHz, 11.025kHz, 12kHz, 16kHz, 22.05kHz, 24kHz, 32kHz, 44.1kHz, 48kHz

• PLL Master Mode:

8kHz, 11.025kHz, 12kHz, 16kHz, 22.05kHz, 24kHz, 32kHz, 44.1kHz, 48kHz

• EXT Master/Slave Mode:

7.35kHz to 48kHz (256fs), 7.35kHz to 48kHz (512fs), 7.35kHz to 13kHz (1024fs)

5. µP I/F: 3-wire Serial, I2C Bus (Ver 1.0, 400kHz Fast-Mode)

6. Master/Slave Mode

7. Audio Interface Format: MSB First, 2’s complement

• ADC: 24bit MSB justified, 16/24bit I2S

• DAC: 24bit MSB justified, 16bit LSB justified, 24bit LSB justified, 24bit I2S

8. Video Functions

• One Composite Signal Input

• Video Amplifier for Composite Signal Output

Gain: +6 / +9 / +12 / +16.5dB

• Low Pass Filter

9. Ta = -30 to 85°C

10. Power Supply:

• Analog Power Supply (AVDD): 2.8 to 3.6V

• Digital Power Supply (DVDD): 1.6 to 2.0V

• Digital I/O Power Supply (TVDD): 1.6 or DVDD – 0.2 to 3.6V

11. Package: 32pin QFN (4.0 x 4.0 mm, 0.4mm pitch)

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