wm8918 Wolfson Microelectronics plc, wm8918 Datasheet - Page 28

• Manufacturer Part Number: wm8918
• Description: Ultra Low Power Dac For Portable Audio Applications
• Manufacturer: Wolfson Microelectronics plc

WM8918
ANALOGUE INPUT SIGNAL PATH
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Up to 2 GPIO pins may be configured for miscellaneous input/output functions such as
button/accessory detect inputs, or for clock, system status, or programmable logic level output for
control of additional external circuitry. Interrupt logic, status readback and de-bouncing options are
supported within this functionality.
The WM8918 has four analogue input pins, which may be used to support connections to multiple
microphone or line input sources. The input multiplexer on the Left and Right channels can be used
to select different configurations for each of the input sources. The analogue input paths can support
line and microphone inputs, in single-ended and differential modes. The input stage can also provide
common mode noise rejection in some configurations.
Two of the analogue input pins have dual functionality and can be used as digital microphone inputs.
(See the “Digital Microphone Interface” section for details.)
The Left and Right analogue input channels are routed to the output multiplexers and PGAs.
The WM8918 input signal paths and control registers are illustrated in Figure 20.
Figure 20 Block Diagram for Input Signal Path
PD, Rev 4.0, September 2010
Production Data
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