GENERAL DESCRIPTION

The AK7722 is a digital signal processor with an integrated 4ch 24bit DAC, a stereo ADC with input selector and a 2ch input ADC. The integrated 4ch DAC, the 2ch ADC with inputselector and the other 2ch ADC feature high performance achieving 108dB, 96dB and 95dB, respectively. The integrated SRC has three input selector enabling the DSP to operate in master mode with digital inputs. The audio DSP has 1536step/fs (at 48kHz sampling) parallel arithmeticoperation performance and the 5k-word delay RAM allows surround processing and time alignment adjusting. As the AK7722 is a RAM based DSP, it is programmable for various user requirements. It is housed in an 80pin LQFP package.

FEATURES

[DSP Block]

- Word length: 24bit (Coefficient RAM& Data RAM: F24 floating point)

- Processing Speed: 13.6 ns (1536step/fs; fs = 48kHz)

- Multiplication: 20 x 24 →44-bit Double precision arithmetic available

- Divider 20 / 20 →20bit

- ALU: 48bit arithmetic operation (overflow margin 4bit) 20bit floating point arithmetic and logic operation

- Program RAM: 3072 x 36bit

- Coefficient RAM: 2048 x 24bit (F24 floating point)

- Data RAM: 2048 x 24-bit (F24 floating point)

- Offset Register: 64 x 13bit

- Delay RAM1: 3072 x 24-bit

- Delay RAM2: 2048 x 24-bit

- Sampling rate: fs= 7.35k ~ 48kHz

- Master Clock: 1536fs(generated from 32fs, 48fs, 64fs, 128fs, 256fs, 384fs by internal PLL)

- Master/Slave Operation

[ADC1 Block]

- Stereo with 6 Inputs Selector

- DR, S/N: 96dB (fs = 48kHz, when differential input)

- S/(N+D): 90dB (fs = 48kHz)

- Differential & Single-ended Inputs

- Digital HPF (fc=1Hz)

- 6 Analog Inputs Selector (2 differential, 4 single-ended)

- Digital Volume Control (24dB ~ -103dB, 0.5dB Step, Mute)

[ADC2 Block]

- DR, S/N: 95dB (fs = 48kHz)

- Single-ended Inputs

- Digital Volume Control (24dB ~ -103dB, 0.5dB Step, Mute)

[SRC Block]

- 3 Pair of Stereo →1 Stereo Pair Selector

- 2ch x 1 system

- Supporting frequency: Fin = 7.35kHz ~ 96kHz →Fout = 7.35kHz ~ 48kHz (FSO/FSI = 0.167~ 6.0)

[Guidance SRC Block] (GSRC)

- 1 Channel (24bit) Up-converter for Voice Guidance

- Supporting frequency: Fin = 7.35kHz ~ 12kHz →Fout = 44.1kHz or 48kHz

[DAC Block]

- 4ch (2 Stereos)

- 24bit 128 x Over-sampling advanced multi-bit (fs=8kHz~48kHz)

- DR, S/N: 108dB (Differential Output)

- S/(N+D): 90dB

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

[Digital Interface Input/Output]

- Digital Signal Input Port (4ch): 24bit MSB justified, 24/20/16bit LSB justified and I2S Format

- Digital Signal Output Port (6ch):

24bit MSB justified, 24/16bit LSB justified and I2S Format

[Micro Computer Interface]

- I2C or 4-wired Interface

[General]

- Integrated PLL

- Integrated Regulator 3.3V →1.8V

- Power Supply: 3.3V ± 0.3V

- Operating Temperature Range: -40˚C ~ 85˚C

- 80pin LQFP