Datasheet

MAX9880A Evaluation Kit
Evaluates: MAX9880A
______________________________________________________________________________________ 17
ADC Input Register
The ADC input register is used to configure the ADC
audio input mixers, as well as configure, enable, and
utilize the device’s auxiliary input (AUX). The ADC Left
and Right Input Mixer windows are accessed by select-
ing the MIX blocks associated with the Left and Right
ADC on the Analog Audio tab. The AUX controls are
provided on the Auxiliary Configuration window, which
is accessed by selecting the AUX[15:0] block (see
Figure 15).
Audio Input Mixers
The left and right input mixers can be configured to
mix audio signals from the analog microphones, single-
ended line inputs, or a combination of both inputs. If an
input mixer is configured to mix the right line input and
the right line input is disabled, then the left line input is
routed to both mixers. This logic is reflected by the input
labels displayed on the ADC MIX blocks.
When an input for the ADC input mixers is selected, the
associated ADC MIX block is highlighted blue to indicate
that this section of the signal path is configured. Note
that when the digital microphone input is enabled, the
corresponding input mixer is disabled (i.e., if the left/right
digital microphone is enabled, the left/right ADC audio
input mixer is disabled).
The input mixer windows also provide the option to syn-
chronize the left and right input mixers. When the Sync
Right and Left checkbox is selected, only one input
mixer window should be open, as this single window
configures both the left and right input mixers.
Auxiliary Input
The auxiliary input is a secondary function of the device’s
JACKSNS pin and is configured through the Auxiliary
Configuration window (Figure 15). The auxiliary input is
used to perform ADC measurements of an external DC
voltage applied to the AUX pad. See the JACKSNS/AUX
section for details on configuring the EV kit hardware for
auxiliary input DC measurements.
Figure 15. Auxiliary Configuration Window