WM8976GEFL/V Wolfson Microelectronics, WM8976GEFL/V Datasheet - Page 46

• Manufacturer Part Number: WM8976GEFL/V
• Description: Audio CODECs Mono ADC Stereo DAC with Spkr
• Manufacturer: Wolfson Microelectronics

Specifications of WM8976GEFL/V

• Mounting Style: SMD/SMT
• Package / Case: QFN-32
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

WM8976
w
AUTO-MUTE
DIGITAL HI-FI DAC VOLUME (GAIN) CONTROL
Table 29 DAC Digital Volume Control
Note: An additional gain of up to +12dB can be added using the gain block embedded in the
digital peak limiter circuit (see DAC OUTPUT LIMITER section).
5-BAND EQUALISER
3-D ENHANCEMENT
DAC DIGITAL OUTPUT LIMITER
The DAC output phase defaults to non-inverted. Setting DACPOLL will invert the DAC output phase
on the left channel and DACPOLR inverts the phase on the right channel.
The DAC has an auto-mute function which applies an analogue mute when 1024 consecutive zeros
are detected. The mute is released as soon as a non-zero sample is detected. Automute can be
disabled using the AMUTE control bit.
The signal volume from each Hi-Fi DAC can be controlled digitally. The gain and attenuation range is
–127dB to 0dB in 0.5dB steps. The level of attenuation for an eight-bit code X is given by:
0.5 × (X-255) dB for 1 ≤ X ≤ 255;
A 5-band graphic equaliser function which can be used to change the output frequency levels to suit
the environment. This can be applied to the ADC or DAC path and is described in the 5-BAND
EQUALISER section for further details on this feature.
The WM8976 has an advanced digital 3-D enhancement feature which can be used to vary the
perceived stereo separation of the left and right channels. See the 3-D STEREO ENHANCEMENT
section for further details on this feature.
The WM8976 has a digital output limiter function. The operation of this is shown in Figure 26. In this
diagram the upper graph shows the envelope of the input/output signals and the lower graph shows
the gain characteristic.
R11
Left DAC
Digital Volume
R12
Right DAC
Digital Volume
REGISTER
ADDRESS
7:0
8
7:0
8
BIT
DACVOLL
[7:0]
DACVU
DACVOLR
[7:0]
DACVU
LABEL
MUTE for X = 0
11111111
( 0dB )
Not
latched
11111111
( 0dB )
Not
latched
DEFAULT
Left DAC Digital Volume Control
0000 0000 = Digital Mute
0000 0001 = -127dB
0000 0010 = -126.5dB
... 0.5dB steps up to
1111 1111 = 0dB
DAC left and DAC right volume do
not update until a 1 is written to
DACVU (in reg 11 or 12)
Right DAC Digital Volume Control
0000 0000 = Digital Mute
0000 0001 = -127dB
0000 0010 = -126.5dB
... 0.5dB steps up to
1111 1111 = 0dB
DAC left and DAC right volume do
not update until a 1 is written to
DACVU (in reg 11 or 12)
DESCRIPTION
PD Rev 4.4 July 2009
Production Data
46