Pre-Production
WM8976
Figure 17 Noise Gate Operation
OUTPUT SIGNAL PATH
The WM8976 output signal paths consist of digital application filters, up-sampling filters, stereo Hi-Fi
DACs, analogue mixers, speaker, stereo headphone and stereo line/mono/midrail output drivers.
The digital filters and DAC are enabled by register bits DACENL And DACENR. The mixers and
output drivers can be separately enabled by individual control bits (see Analogue Outputs). Thus it is
possible to utilise the analogue mixing and amplification provided by the WM8976, irrespective of
whether the DACs are enabled or not.
The WM8976 DACs receive digital input data on the DACDAT pin. The digital filter block processes
the data to provide the following functions:
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Digital volume control
Graphic equaliser
Digital peak limiter.
Sigma-Delta Modulation
High performance sigma-delta 24-bit audio DAC converts the digital data into an analogue signal.
PP Rev 3.0 April 2006
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
