CODEC Motherboard Manual Version 1.3
Page 23 of 66
April 12, 2016
CODEC Motherboard
9 Input Path Control Panel
This Control Tab gives access to the various controls and settings for the analog audio input
routing, power management, and gain blocks up to, but not including, the ADC converters.
Control of these bits is normally automatic when using the Demo Panel. These bit controls are
provided here for convenient manipulation and evaluation of the input path features and settings.
The function of each of these control bits is explained in detail in the NAU8822 device Design
Guide documentation. The names for each control in this panel match the names given to
specific control bits in the NAU8822 control registers. The description and function for each of
these bits can be found (most easily by doing a text string search) in the Details of Register
Operation appendix portion of the NAU8822 device Design Guide. It can also be helpful to switch
to the Path View tab to better see how each of these controls affects the device settings and
routing.
Figure 10: INPUT PATH CONTROL PANEL
9.1
Microphone Bias
This section also provides control over the microphone bias circuit. This function provides low-
noise DC power from the MICBIAS output pin that is normally used to power one or more external
microphones. The description and function for each of these bits can be found (most easily by
doing a text string search) in the functional descriptions, and also, the Detailed Register Map in
the NAU8822 device Design Guide.
