Using The Evaluation Board - Analog Devices EVAL-ADAU1466Z User Manual

UG-1135

USING THE EVALUATION BOARD

POWER SUPPLY
Power is supplied to the evaluation board using a dc power
supply with a female positive center plug. The plug has a 2.1 mm
inner diameter, a 5.5 mm outer diameter, and a 9.5 mm length
(see Figure 59). The output must range between 5 V and 7 V
and must be able to source at least 1.5 A of current. Connect the
power supply to Connector J4. The unregulated supply powers
the operational amplifiers used in the active audio filters for the
analog audio inputs and outputs. An on-board linear regulator
(U5) generates the 3.3 V dc supply required for the
and AD1938, as well as other supporting ICs. When the power
supply is connected properly, LED D2 (A_3V3) illuminates.
Figure 59. DC Power Supply Plug and Cable
INPUTS AND OUTPUTS
The EVAL-ADAU1466Z provides access to the serial ports,
S/PDIF interfaces, multipurpose pins, and auxiliary analog-to-
digital converters (ADCs) of the ADAU1466.
AD1938 Codec
Two of the four serial input ports are connected to the ADCs of
the AD1938, and all four of the serial output ports are connected
to the digital-to-analog converters (DACs) of the AD1938, for a
total of four channels of analog audio input and eight channels
of analog audio output.
The AD1938 is hardwired in standalone mode, and its serial
ports are configured as clock slaves. Therefore, the corresponding
serial ports on the ADAU1466
default, all serial ports on the
when a new project is created in SigmaStudio.
Table 2. Mapping of Stereo Analog Input Signals to
Input Jack Plug Contact
J9 Left (tip)
J9 Right (ring)
J7 Left (tip)
J7 Right (ring)
ADAU1466
must be set as clock masters. By
ADAU1466 are set as clock masters
SigmaStudio
AD1938 ADC Pins
ADC1LN, ADC1LP
ADC1RN, ADC1RP
ADC2LN, ADC2LP
ADC2RN, ADC2RP
Standalone mode eliminates the need and ability of the user to
configure the registers of the
fixes the sample rate of the
not possible to change this setting. Even though the
is flexible and can run at any sample rate up to 192 kHz, the analog
audio inputs and outputs on the EVAL-ADAU1466Z can be
distorted or silent if a sample rate other than 44.1 kHz or 48 kHz is
used for the ADAU1466
Stereo Line Inputs
Two stereo input jacks allow four, single-ended, line level, analog
input signals. The
the full scale is 2.8 V p-p, which is ~1 V rms for a sine wave. Any
signal that exceeds 2.8 V p-p at the audio jack is clipped, which
creates distortion. The signals are fed to active low-pass filters
and converted to differential pairs before reaching the ADCs of
the AD1938. The filters are designed for a system sample rate of
44.1 kHz or 48 kHz.
The stereo input jacks accept standard stereo TRS 3.5 mm
(1/8 inch) mini plugs (tip connected to left, ring connected to
right, sleeve connected to ground) with two channels of audio
(see Figure 60).
Figure 60. Standard Stereo TRS 1/8 Inch Mini Audio Plug and Cable
The signals pass through the
to the ADAU1466
of input signals to input channels in
is shown in Table 2.
Channels
ADAU1466 Serial Input Pins
SDATA_IN0
SDATA_IN0
SDATA_IN1
SDATA_IN1
Rev. 0 | Page 18 of 45
EVAL-ADAU1466Z
AD1938 via its SPI port. This mode
AD1938 at 44.1 kHz or 48 kHz. It is
serial ports.
AD1938 ADC inputs are configured such that
AD1938 ADCs and then are sent
2
serial input ports in I S format. The mapping
SigmaDSP and
Input Channel in SigmaStudio
0
1
16
17
User Guide
ADAU1466
SigmaStudio