WM8946ECSSLASHR datasheet(62/175 Pages) WOLFSON

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WM8946

Production Data

PD, July 2012, Rev 4.3

ANALOGUE OUTPUTS

The Line outputs and Speaker outputs are highly configurable and may be used in many different

ways. The output mixers can be configured to generate mono or stereo, single-ended or differential

outputs. The Class AB Speaker output driver can deliver up to 400mW into an 8

 speaker in BTL

mode. Alternatively, the Speaker outputs can deliver 40mW to a stereo 16

 headphone load.

LINE OUTPUTS

The line outputs LINEOUTL and LINEOUTR are the external connections to the Line output mixers. In

a typical application, these will deliver a stereo pair of outputs in single-ended configuration.

For stereo line output, the Left and Right output mixers are used to generate the Left and Right output

signals respectively.

A differential mono (left+right) DAC output may be generated at the line outputs by routing an inverted

DAC signal to one output and the non-inverted signal from the other DAC to the other line output.

A differential output from a single DAC may be generated at the line outputs by routing the inverted

DAC signal to one output and the non-inverted DAC signal to the other. When the speaker outputs

are similarly configured for the other DAC channel, then stereo differential output is possible.

SPEAKER OUTPUTS

The speaker outputs SPKOUTL and SPKOUTR are the external connections to the Speaker Output

mixers. These outputs are intended for a mono speaker or headphone in BTL configuration or for a

stereo line load.

For stereo line configuration, the Left and Right Speaker Output mixers are used to generate the Left

and Right output signals respectively.

For mono speaker or headphone configuration, a BTL output from the DACs may be generated by

routing an inverted DAC signal to one speaker output and the non-inverted signal from the other DAC

to the other speaker output. The auxiliary inputs AUX1 or AUX2 may be routed to the mono speaker

by enabling the respective signal path in either the Left or Right speaker output mixer. (Note that

these signals should not be enabled in both mixers at once; this will lead to cancellation at the BTL

output.)

Note that a differential output from a single DAC may be generated at the speaker outputs by routing

the inverted DAC signal to one output and the non-inverted DAC signal to the other. When the line

outputs are similarly configured for the other DAC channel, then stereo differential output is possible.

EXTERNAL COMPONENTS FOR LINE OUTPUT

In single-ended output configurations, DC blocking capacitors are required at the output pins

(LINEOUTL, LINEOUTR, SPKOUTL and SPKOUTR). See “Applications Information” for details of

these components.

WM8946ECS/R Datasheet(PDF) 62 Page - Wolfson Microelectronics plc