Wolfson DVD-RW and PVR application codec

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Wolfson has introduced a new stereo codec (CODEC) with the ability to run analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) simultaneously at different sample rates. This feature is ideal for DVD recorders (DVD-RW), LCD TVs, and similar consumer electronics applications, enabling end users to simultaneously play and record DVD or TV content.

The product of the Wolfson WM8591 codec is the use of a separate, small codec chip instead of two separate analog-to-digital converters and digital-to-analog converter chips, providing designers with cost savings and component reduction. The number of components and the possibility of reducing the PCB area outweigh the existing solutions.

The WM8591 also includes an analog programmable gain amplifier (PGA). The PGA can be used to adjust the sensitivity of the analog input to ensure consistent recording levels, or as a limiter to avoid analog input overload distortion.

The WM8591 is a single-ended, two-wire WM8590 version with an excellent digital-to-analog converter with a signal-to-noise ratio of 110dB and an analog-to-digital converter with a signal-to-noise ratio of 102dB. Unlike many traditional solutions that require a multi-wire control system, this single two-wire interface can be connected to a variety of devices including volume control, mute and de-emphasis, greatly reducing the design cycle. . Various single-ended inputs to analog-to-digital converters and multiple differential outputs from digital-to-analog converters further enable designers to achieve high performance while reducing system complexity.

Like the WM8590, the new WM8591 is based on a 24-bit sigma delta analog-to-digital converter with a programmable input gain and limiter control. The analog gain can be adjusted from +24 to –21dB in 0.5dB steps, while the digital gain can be programmed from –21.5dB to –103dB in 0.5dB steps. It supports output words from 16 to 32 bits long and has a sample rate of 32 to 96 kHz. The device's audio data interface supports I2S, left-justified, right-justified, and DSP formats. The digital-to-analog converter supports sample rates from 32 to 192 kHz and can be programmed independently of the analog-to-digital converter's sample rate.

Samples of the Wolfson WM8591 are available now and will be available in volume in the fourth quarter. The price is $1.45 when the purchase price is 10,000 pieces.