As the latest addition to AKM Semiconductor's Audio4pro family, the 24-bit, stereo AK4556 is the next generation 3-V high-performance CODEC. The device supports sampling rates of up to 216 kHz, which makes the CODEC well-suited for professional variable-pitch applications. Compared to the current-generation AK4552, the AK4556 sports 6-dB better dynamic performance — to 103 dB for the analog-to-digital converter (ADC) and 106 dB for the digital-to-analog converter (DAC). It is layout-compatible with the older device to make upgrading easier.
The flexible digital audio interface supports MSB-justified and I2S formats for the ADC output, and MSB-justified, LSB-justified, and I2S formats for the DAC input. The ADC uses an enhanced, dual-bit architecture with a linear phase decimation digital filter. The FIR filter has a short group delay of 21 fs, independent of the sampling rate. The DAC makes full use of the company's advanced multi-bit delta-sigma modulator with a linear interpolation digital filter. It also offers the jitter-resistant performance of AKM's switched-capacitor filter technology.
The AK4556's operating voltage ranges from 2.4 to 3.6 V (at fs = 8 to 108 kHz), and 2.7 to 3.6 V (at fs = 108 to 216 kHz). Power dissipation at fs = 48 kHz is 82 mW. The AK4556 comes in a 20-pin TSSOP package. Samples and evaluation boards are available now, and prices start at $1.91 in quantities of 10,000. The datasheet may be downloaded at: www.akm.com/datasheets/ak4556_f00e.pdf.