Low-power ADC aims for handheld audio

The WM8737L is a high-performance, ultra-low-power stereo audio ADC with 97dB signal-to-noise ratio and microphone pre-amplifier noise performance in the submicrovolt range.

The WM8737L is a high-performance, ultra-low-power stereo audio ADC with 97dB signal-to-noise ratio (SNR) and microphone pre-amplifier noise performance in the submicrovolt range.

The new ADC is designed specifically for portable applications such as minidisk players and memory audio/voice recorders.

The optimal SNR performance (A weighted) of 97dB occurs at normal power mode of 3.3V.

In low-power mode, stereo, with microphone preamps off, the WM8737L draws only 8mW at 1.8V and 18.5mW at 3.3V.

The analogue and digital I/O uses 1.8-3.6V power supplies, and the digital core uses 1.42-3.6V.

To save power the WM8737L can run in mono mode for mono signals or mix stereo channels into mono in either analogue or digital domain.

The WM8737L includes three sets of stereo inputs configurable for line-level signals, internal or tabletop microphones, or for DC measurement.

A programmable gain amplifier can be used for automatic level control with user programmable hold, attack and decay times.

The device is controlled via a two- or three-wire serial interface, providing access to all features including gain control, analogue or digital mono mixing and power management facilities.

"There is generally a tradeoff between performance and low power in mixed signal semiconductors, but the WM8737 provides the best of both options in a single device", said Julian Hayes, Vice President of Marketing for Wolfson.

The WM8737L is supplied in a leadless, 5 x 5mm QFN package and is available now.

Device drivers for selected platforms and operating systems are also available.

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