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Product Brief WM8956

Hi-Fi DAC with 1W Stereo Class D Speaker Drivers and

Headphone Drivers

WOLFSON MICROELECTRONICS plc

Preliminary Technical Data , September 2006, Rev 2.1

Copyright

2006 Wolfson Microelectronics plc

DESCRIPTION

The WM8956 is a low power, high quality stereo DAC designed

for portable multimedia applications.

Stereo class D speaker drivers provide 1W per channel into 8

Ω

loads with a 5V supply. Low leakage, excellent PSRR and

pop/click suppression mechanisms also allow direct battery

connection to the speaker supply. Flexible speaker boost

settings allow speaker output power to be maximised while

minimising other analogue supply currents.

A highly flexible input configuration for up to three stereo

sources is integrated, with a complete microphone interface.

External component requirements are drastically reduced as no

separate microphone, speaker or headphone amplifiers are

required.

Stereo 24-bit sigma-delta DACs are used with low power over-

sampling digital interpolation filters and a flexible digital audio

interface.

The master clock can be input directly or generated internally by

an onboard PLL, supporting most commonly-used clocking

schemes.

The WM8956 operates at analogue supply voltages down to

2.7V, although the digital supplies can operate at voltages down

to 1.71V to save power. The speaker supply can operate at up

to 5.5V, providing 1W per channel into 8

Ω loads. Unused

functions can be disabled using software control to save power.

The WM8956 is supplied in a very small and thin 5x5mm QFN

package, ideal for use in hand-held and portable systems.

FEATURES

•

DAC SNR 98dB (‘A’ weighted), THD -84dB at 48kHz, 3.3V

•

Pop and click suppression

•

3D Enhancement

•

Stereo Class D Speaker Driver

-

<0.1% THD with 1W per channel into 8

Ω BTL speakers

-

70dB PSRR @217Hz

-

87% efficiency (1W output)

-

Flexible internal switching clock

•

On-chip Headphone Driver

-

40mW output power into 16

Ω at 3.3V

-

Capless mode support

-

THD -75dB at 20mW, SNR 90dB with 16

Ω load

•

Microphone Interface

-

Pseudo differential for high noise immunity

-

Integrated low noise MICBIAS

•

Low Power Consumption

-

10mW headphone playback (2.7V / 1.8V supplies)

•

Low Supply Voltages

-

Analogue 2.7V to 3.6V (Speaker supply up to 5.5V)

-

Digital core and I/O: 1.71V to 3.6V

•

On-chip PLL provides flexible clocking scheme

•

Sample rates: 8, 11.025, 12, 16, 22.05, 24, 32, 44.1, 48

•

5x5x0.9mm QFN package

APPLICATIONS

•

Mobile multimedia

•

Portable media / DVD players

•

Games consoles