AK4953A设计的24位立体声CODEC技术

    本文介绍了AK4953A主要特性,方框图, 立体声和单声道的数字MIC连接案例, 3线串接模式的系统连接框图以及AKD4953-A评估板主要特性,方框图和电路图.

    AK4953A是AKM 公司的集成了MIC/HP/SPK-AMP的24位立体声CODEC,输入电路包括麦克风放大器和自动音量控制(ALC)电路,输出电路包括无电容的耳机放大器和扬声器放大器,集成的电荷泵电路产生负电压,因此输出不需要AC耦合电容,工作电压0.9V-5.5V,主要用在具有录音和播放功能的手提设备.

    AK4953A主要特性:

    1. Recording Function

    o Stereo Single-ended input with three Selectors

    o MIC Amplifier (+29dB/+26dB/+23dB/+20dB/+16dB/+12dB/0dB)

    o Digital ALC (Automatic Level Control)(Setting Range: +36dB ~ -54dB, 0.375dB Step)

    o ADC Performance: S/(N+D): 82dB, DR, S/N: 88dB (MIC-Amp=+20dB)S/(N+D): 85dB, DR, S/N: 96dB (MIC-Amp=0dB)

    o Wind-noise Reduction Filter

    o 5 Band Notch Filter

    o Digital MIC Interface

    2. Playback Function

    o Digital De-emphasis Filter (tc=50/15μs, fs=32kHz, 44.1kHz, 48kHz)

    o Digital ALC (Automatic Level Control)(Setting Range: +36dB ~ -54dB, 0.375dB Step)

    o Digital Volume Control (+12dB ~ -115dB, 0.5dB Step, Mute)

    o Capacitor-less Stereo Headphone Amplifier

    - HP-Amp Performance: S/(N+D): 80dB@24mW, S/N: 96dB

    - Output Power: 24mW@16Ω

    - Pop Noise Free at Power-ON/OFF

    o Mono Speaker-Amplifier

    - SPK-Amp Performance: S/(N+D): 70dB@250mW, S/N: 95dB

    - BTL Output

    - Output Power: 400mW@8Ω (SVDD=3.3V)100mW@8Ω (SVDD=1.5V)

    o Beep Generator

    3. Power Management

    4 . Master Clock:(1) PLL Mode
   
    o Frequencies: 11.2896MHz, 12MHz, 13.5MHz, 24MHz, 27MHz (MCKI pin)32fs or 64fs (BICK pin)(2) External Clock Mode

    o Frequencies: 256fs, 384fs, 512fs or 1024fs (MCKI pin)5. Output Master Clock Frequencies: 32fs/64fs/128fs/256fs

    o PLL Slave Mode (BICK pin): 7.35kHz ~ 96kHz

    o PLL Slave Mode (MCKI pin): 7.35kHz, 8kHz, 11.025kHz, 12kHz, 14.7kHz, 16kHz,22.05kHz, 24kHz, 29.4kHz, 32kHz, 44.1kHz, 48kHz,64kHz, 88.2kHz, 96kHz

    o PLL Master Mode: 7.35kHz, 8kHz, 11.025kHz, 12kHz, 14.7kHz, 16kHz, 22.05kHz,24kHz, 29.4kHz, 32kHz, 44.1kHz, 48kHz, 64kHz, 88.2kHz,96kHz

    o EXT Master/Slave Mode: 7.35kHz ~ 96kHz (256fs), 7.35kHz ~ 48kHz (384fs),7.35kHz ~ 48kHz (512fs), 7.35kHz ~ 12kHz (1024fs)

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

    7. Master/Slave mode

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

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

    o DAC: 24bit MSB justified, 16bit LSB justified, 24bit LSB justified, 16/24bit I2S

    9. Ta = -30 ~ 85°C (SPK-Amp = OFF)Ta = -30 ~ 70°C (SPK-Amp = ON)

    10. Power Supply:

    o Analog Power Supply (AVDD): 2.85 ~ 3.5V

    o Digital Power Supply (DVDD): 1.6 ~ 2.0V

    o Digital I/O Power Supply (TVDD): DVDD ~ 3.5V

    o Speaker Power Supply (SVDD): 0.9 ~ 5.5V

    11. Package: 36pin QFN (5 x 5mm, 0.4mm pitch)

    AKD4953-A评估板

    The AKD4953-A is an evaluation board for the AK4953 24bit CODEC with built-in PLL and MIC/HP/SPK Amplifier. The AKD4953-A has the interface with AKM’s A/D evaluation boards. Therefore, it’s easy to evaluate the AK4953. The AKD4953-A also has the digital audio interface and can achieve the interface with digital audio systems via opt-connector.

    AKD4953-A评估板功能:

   o Compatible with 2 types of interface

     - Direct interface with AKM’s A/D converter evaluation boards

   - DIT/DIR with optical input/output

     o BNC connector for an external clock input

    o 10pin header for serial control interface