AK7755EN

Description

The AK7755 is a highly integrated digital signal processor, including a mono ADC, a stereo audio CODEC, a MIC pre-amplifier, a line-out amplifier and digital audio I/F. The audio DSP has 2560step at fs = 48kHz parallel processing power. As the AK7755 is a RAM based DSP, it is programmable for user requirements such as high performance hands free function and acoustic effects. The AK7755 is available in a space saving small 36-pin QFN package.

Features

DSP
- Word length: 24-bit (Data RAM 24-bit floating point)
- Instruction cycle: 8.1ns (2560fs at fs=48kHz)
- Multiplier 24 x 24 → 48-bit (double precision available)
- Divider 20 / 20 → 20-bit (with floating point normalization function)
- ALU: 52-bit arithmetic operation (with overflow margin 4-bit)
- Program RAM: 4096 × 36-bit
- Coefficient RAM: 2048 × 24-bit
- Data RAM: 2048 × 24-bit (24-bit floating point)
- Offset Register: 32 × 13-bit
- Delay RAM: 8192 × 24-bit
- Accelerator Coefficient RAM: 2048 × 20-bit
- Accelerator Data RAM: 2048 × 16-bit
- JX pins (Interrupt)
- Master/Slave Operation
- Master Clock: 2560fs
(Internally Generated by PLL from 32, 48, 64, 128, 256 and 384fs clock)

Two Digital Interfaces (I/F1, I/F2)
- Digital Signal Input Port (4ch): MSB justified 24-bit, LSB justified 24/20/16-bit, I2S
- Digital Signal Input Port (6ch): MSB justified 24-bit, LSB justified 24/20/16-bit, I2S
- Short / Long Frame
- 24-bit linear, 8-bit A-law, 8-bit μ-law
- TDM 256fs (8ch) MSB justified and I2S formats

Stereo 24-bit ADC:
- Sampling Frequency: fs=8kHz ~ 96kHz
- ADC Characteristics S/(N+D): 91dB, DR, S/N: 102dB
- Two-Channel Analog Input Selector (Differential, Single-ended Input)
- Channel Independent Mic Analog Gain Amplifier
(0~18dB (2dB Step), 18~36dB (3dB Step))
- Analog DRC (Dynamic Range Control)
- Channel Independent Digital Volume (24~-103dB, 0.5dB Step Mute)
- Digital HPF for DC Offset Cancelling

Mono 24-bit ADC
- Sampling Frequency: 8kHz ~ 96kHz
- ADC Characteristics S/(N+D): 90dB; DR, S/N: 100dB
- Line Amplifier: 21dB ~ -21dB, 3dB Step
- Digital Volume (24dB ~ -103dB, 0.5dB step, Mute)
- Digital HPF for DC Offset Cancelling