AC '97 codec provides high-quality PC audio

Designed to meet the needs of a broad range of high-quality, PC audio applications, TI has developed a highly-integrated stereo audio codec compliant with the Intel AC ’97 specification.

The TLC320AD91 performs full-duplex 18-bit codec functions at 48 k samples/second. It also provides a comprehensive analog mixer with four sets of stereo inputs, plus telephone, two microphone, and PC-beep inputs. On-chip reference circuits generate the necessary bias voltages for the device, and a five-pin digital bi-directional serial interface allows data transfer to and from the AC ’97 controller.

The ’AD91 provides performance of 90 dB typical signal-to-noise ratio (SNR) on the DAC and 80 dB SNR on the ADC, surpassing the specification requirements. The codec also exceeds other parameters like intermodulation distortion and crosstalk, where the ’AD91 provides 100 dB for crosstalk. In addition, the ’AD91 adds high-quality FIR and Bissel Linear Phase Filtering and 46 dB power supply rejection ratio (PSRR) for improved performance.

The ’AD91 is available in a 48-pin TQFP and is characterized for operation from 0 to 70°C.

Key specifications TLC320AD91

Digital interface 5 V or 3.3 V

Sampling rate, max. 48 kHz

Resolution 18 bits

DAC SNR 90 dB

ADC SNR 80 dB

PSRR 46 dB