基于AK4953A的24位立體聲CODEC設計

本文介紹了AK4953A主要特性,方框圖, 立體聲和單聲道的數(shù)字MIC連接案例, 3線串接模式的系統(tǒng)連接框圖以及AKD4953-A評估板主要特性,方框圖和電路圖.

AK4953A是AKM 公司的集成了MIC/HP/SPK-AMP的24位立體聲CODEC,輸入電路包括麥克風放大器和自動音量控制(ALC)電路,輸出電路包括無電容的耳機放大器和揚聲器放大器,集成的電荷泵電路產(chǎn)生負電壓,因此輸出不需要AC耦合電容,工作電壓0.9V-5.5V,主要用在具有錄音和播放功能的手提設備.

AK4953A主要特性:

1. Recording Function

? Stereo Single-ended input with three Selectors

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

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

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

? Wind-noise Reduction Filter

? 5 Band Notch Filter

? Digital MIC Interface

2. Playback Function

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

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

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

? 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

? 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)

? Beep Generator

3. Power Management

4. 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, 384fs, 512fs or 1024fs (MCKI pin)5. Output Master Clock Frequencies: 32fs/64fs/128fs/256fs

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

? 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

? 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

? 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

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

? 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:

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

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

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

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

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

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圖1.AK4953A方框圖

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圖2.AK4953A立體聲數(shù)字MIC連接案例框圖

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圖3.AK4953A單聲道數(shù)字MIC連接案例框圖

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圖4.AK4953A系統(tǒng)連接框圖(3線串接模式)

AKD4953-A評估板

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評估板功能:

? Compatible with 2 types of interface

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

- DIT/DIR with optical input/output

? BNC connector for an external clock input

? 10pin header for serial control interface

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圖5.AKD4953-A評估板方框圖

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圖6.AKD4953-A評估板電路圖(1)

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圖7.AKD4953-A評估板電路圖(2)

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圖8.AKD4953-A評估板電路圖(3)

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圖9.AKD4953-A評估板電路圖(4)

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圖10.AKD4953-A評估板電路圖(5)

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圖11.AKD4953-A評估板電路圖(6)