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4.5
Audio Input/ADC Tab
TLV320AIC3104EVM Software
Figure 7. Audio Input Tab
The Audio Input/ADC Tab allows control of the analog input mixer and the ADC. The controls are
displayed to look similar to an audio mixing console (see
). Each analog input channel has a
vertical strip that corresponds to that channel. By default, all inputs are muted when the TLV320AIC3104
is powered up.
To route an analog input to the ADC:
1. Select the Input Mode button to correctly show if the input signal is single-ended (SE) or
fully-differential (Diff). Inputs that are single-ended should be made to the positive signal terminal.
2. Click on the button of the analog input channel that corresponds to the correct ADC. The caption of the
button should change to Active. Note that the user can connect some channels to both ADCs, while
others will only connect to one ADC.
3. Adjust the Level control to the desired attenuation for the connected channel. This level adjustment
can be done independently for each connection.
The TLV320AIC3104 offers a programmable microphone bias that can either be powered down or set to 2
V, 2.5 V, or the power supply voltage of the ADC (AVDD_ADC). Control of the microphone bias (mic bias)
voltage is accomplished by using the Mic Bias pulldown menu button above the last two channel strips.
To use the onboard microphone, JMP2 and JMP3 must be installed and nothing should be plugged into
J6. In order for the mic bias settings in the software to take effect, JMP1 should be set to connect
positions 2 and 3, so that mic bias is controlled by the TLV320AIC3104.
In the upper right portion of this tab are controls for Weak Common Mode Bias. Enabling these controls
will result in unselected inputs to the ADC channels to be weakly biased to the ADC common mode
voltage.
SLAU218 – August 2007
TLV320AIC3104EVM and TLV320AIC3104EVM-PDK
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