The latest addition to the Audio4Pro family is the AK4556 24-bit, 3-V stereo CODEC from AKM Semiconductor, which meets the requirements of both the professional and consumer markets. The AK4556 supports sampling rates of up to 216 kHz, which makes the device well-suited for professional variable-pitch applications. Dynamic performance has been upgraded to 103 dB for the analog-to-digital converter (ADC) and 106 dB for the digital-to-analog converter (DAC), which is 6-dB better than the previous-generation AK4552. Operating voltage ranges include 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 only 82 mW. The new CODEC is layout compatible with the AK4552.
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 output. 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 and the offers jitter-resistant performance of AKM's switched-capacitor filter technology.
The AK4556 is available in a 20-pin TSSOP package. Samples and evaluation boards are available now, and the data sheet may be downloaded at www.akm.com/datasheets/ak4556_f00e.pdf. Prices start at $1.91 for 10,000 unit quantities.