WM8976GEFL/V Wolfson Microelectronics, WM8976GEFL/V Datasheet - Page 22

• 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
INPUT SIGNAL PATH
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MICROPHONE INPUTS
The WM8976 can accommodate a variety of microphone configurations including single ended and
differential inputs. The inputs to the differential input PGA are LIN, LIP and L2.
In single-ended microphone input configuration the microphone signal should be input to LIN and the
internal NOR gate configured to clamp the non-inverting input of the input PGA to VMID.
In differential mode the larger signal should be input to LIP and the smaller (e.g. noisy ground
connections) should be input to LIN.
Figure 10 Microphone Input PGA Circuit
The input PGA is enabled by the IPPGAENL register bits.
Table 4 Input PGA Enable Register Settings
The WM8976 has flexible analogue inputs. An input PGA stage is followed by a boost/mix stage
which drives into the hi-fi ADC. The input path has three input pins which can be configured in a
variety of ways to accommodate single-ended or differential microphones. There is an auxiliary input
pin which can be fed into to the input boost/mix stage as well as driving into the output path. A
bypass path exists from the output of the boost/mix stage into the output left/right mixers.
R2
Power
Management
2
REGISTER
ADDRESS
2
BIT
INPPGAENL
LABEL
0
DEFAULT
Input PGA enable
0 = disabled
1 = enabled
DESCRIPTION
PD Rev 4.4 July 2009
Production Data
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