A two-channel 16/18 b audio AD/DA including filter function with 60/40 mW power consumption at 2.7 V

This codec chip is a complete two-channel low-voltage A/D and D/A conversion system with all associated filter functions. It is intended for portable digital audio recording equipment, such as DCC and MD as well as for digital personal communication systems. Each channel has its own independent A/D and D/A converters. The high degree of analog and digital integration results in an easily-applicable circuit with few external components and power consumption of only 40 mW for the D/A and 60 mW for the A/D, at a supply voltage of 2.7 V. The conversion techniques used yield a full-scale THD+N of -90 dB for both converters, and a dynamic range of 96 dBA for the A/D and 105 dBA for the D/A, representing a resolution of 16 and 18b respectively. The sample rate can be anywhere in the range from 28 to 54 kHz. The chip is fabricated in a low-threshold 0.8 /spl mu/m CMOS process.