New ADCs support DSD

Texas Instruments has unveiled stereo analog-to-digital converters that support high-end audio in home entertainment systems.

Providing a high-performance audio solution for the home entertainment market, Texas Instruments has unveiled analog-to-digital converters (ADC) that support high-end audio in home entertainment systems – the Direct Stream Digital (DSD) specification and the Super Audio CD format (SACD).

Recognising the consumer’s need for low cost, quality audio equipment, this family of devices is suitable for mainstream consumer audio equipment such as DVD, CD, and MD players, as well as high-end audio/video amplifiers and receivers.

Expanding its PCM180x audio ADC family, TI introduced two 24-bit devices, the PCM1804 and the smaller PCM1802.

‘The next-generation digital audio market forming around new audio formats like SACD and DVD-Audio is showing astounding growth,’ said Yuzo Sugiki, marketing manager, TI Digital Audio.

‘According to a November 2000 Dataquest report, the average annual share (on a unit basis) of audio players supporting the SACD format will increase 128 percent between 2000 and 2004, while DVD players, both DVD-Audio and DVD-Audio/Video, are projected to increase their share by 274 percent over the same period.’

The PCM1804 is a differential input 24-bit ADC with a 192 kHz maximum sampling rate, a dynamic range of 112dB and THD+N at -102dB. Previously, audio ADCs have required delta-sigma modulators with a 2-bit or greater digital-to-analog converter (DAC) in a loop in order to provide 110dB or more of dynamic range.

In contrast, the PCM1804 uses a proprietary architecture and complementary analog circuitry to provide direct 64fs 1-bit streaming data from the modulator output, enabling it to truly meet the DSD specification.

The PCM1804 contains a built-in anti-aliasing digital filter with -100dB stop-band attenuation and +/- 0.005dB pass band ripple. The device uses dual-voltage power supply at 5V analog and 3.3V digital with a +/- 2.5 V differential inputs. Moreover, the PCM1804 has a selectable master/slave audio interface and system clock speeds of 128, 256, 512 and 786 fs.

TI also announced the PCM1802 stereo ADC with single-ended input, featuring 24-bit sampling and a 96 kHz maximum sampling rate. The PCM180x family also includes the PCM1800 20-bit stereo ADC and the PCM1801 16-bit ADC.

The PCM1804 and PCM1802 ADCs are available now from TI and its authorised distributors. The PCM1804 is packaged in a 28-pin SSOP and suggested resale pricing is $4.95 in quantities of 1,000. The PCM1802 is packaged in a 20-pin SSOP and suggested resale pricing is $3.95 in quantities of 1,000.

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