Analog Devices EVAL-ADAU1777Z, Руководство пользователя

Страница: 12 / 26

EVAL-ADAU1777Z User Guide UG-1055
Rev. 0 | Page 11 of 25
USING THE EVALUATION BOARD
POWER
Power can be supplied to the EVAL-ADAU1777Z in one of three
ways. When Jumper J3 is in the USB/EXT position, power can be
supplied by connecting the
EVAL-ADUSB2EBZ (USBi) board
to J1 (see Figure 30) or by connecting a 3.8 V dc to 5.5 V dc
power supply to J2 (tip positive).
15054-
030
Figure 30. Header J1, Control Port
To supply power via a 1.5 V battery, J3 must be set to the BATT
position, and the battery must be connected to J5. The on-
board regulator generates the 3.3 V dc or 1.8 V dc supply,
determined by S1, for the on-board circuitry. LED D1 lights up
when power is supplied to the board. To connect power to the
ADAU1777 , connect the J8, J10, J12, and J17 jumpers (see
Figure 31).
150
54-
031
Figure 31. Power Jumpers
INPUTS AND OUTPUTS
The EVAL-ADAU1777Z has multiple audio input and output
options, including digital and analog. There are four single-
ended analog inputs that are configurable as microphone or line
inputs, dual stereo digital microphone inputs, and two
differential outputs that can also be used in a single-ended
configuration.
Analog Microphone Inputs
For microphone signals, the ADAU1777 analog inputs can be
configured as single-ended inputs with optional programmable
gain amplifier (PGA) mode.
Microphone Bias
To add MBIAS0 to AIN0, connect a jumper to the J11 header.
Similarly, MBIAS1 or MBIAS0 can be added to AIN1 by
connecting a jumper to the J14 header (see Figure 32).
15054-
032
Figure 32. Microphone Bias Headers
Enable the microphone bias circuitry in the PGA/ADC tab of
SigmaStudio . The appropriate gain settings can also be chosen
via this tab (see Figure 33).
15054
-033
Figure 33. Microphone Bias Enable and Gain
Stereo Line Input
The J22 stereo input jack accepts a standard stereo TRS 3.5 mm
mini plug (tip is left, ring is right) with two channels of audio.