WM8350GEB/V Wolfson Microelectronics, WM8350GEB/V Datasheet - Page 63

• Manufacturer Part Number: WM8350GEB/V
• Description: Audio CODECs Audio CODEC plus pwr management
• Manufacturer: Wolfson Microelectronics

Specifications of WM8350GEB/V

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Production Data
13.4 INPUT SIGNAL PATH
w
Power Down:
1.
2.
3.
4.
5.
6.
7.
The WM8350 has multiple analogue inputs. There are two input channels, Left and Right, each of
which consists of an input PGA stage followed by a boost/mix stage switch into the hi-fi ADC. Each
input PGA path has three input pins which can be configured in a variety of ways to accommodate
single-ended, differential or dual differential microphones. There are two auxiliary input pins 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.
13.4.1
The microphone inputs of the WM8350 are designed to accommodate electret condenser
microphones or analogue line-in signals. They comprise the following pins:
The non-inverting inputs have constant input impedance to VMID, whereas the inverting input’s
impedance varies with the pre-amplifier’s gain. (Note: the terms “inverting” and “non-inverting” refer
to the microphone pre-amplifiers only. For overall behaviour, the inverting record mixer and the ADC,
whose output can optionally be inverted in the digital domain, must also be taken into account.)
Each
pseudo-differentially connected microphones. The amplified signal for each channel can be digitised
in the audio ADC and/or mixed into the output signal path.
Mute all outputs
Enable anti-pop circuits by setting ANTI_POP = 01.
Disable circuits down-stream on outputs
Disable VMID by setting VMID_ENA = 0.
Wait for VMID to discharge (typically 500ms)
Disable the anti-pop circuits by setting ANTI_POP = 00.
Disable all outputs
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channel
MICROPHONE INPUTS
IN1LP: first non-inverting input, left channel
IN2L: second non-inverting input, left channel
IN1LN: inverting input, left channel
IN1RP: first non-inverting input, right channel
IN2R: second non-inverting input, right channel
IN1RN: inverting input, right channel
has
a
programmable
pre-amplifier,
which
supports
PD, March 2010, Rev 4.2
single-ended
WM8350
or
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