Analog Devices ADAU1977, Руководство пользователя

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Evaluation Board User Guide UG-600
EVALUATION BOARD HARDWARE
The EVAL-ADAU1977Z board is common for the ADAU1977 ,
ADAU1978 , and ADAU1979 . The evaluation board is designed
as a 4-layer printed circuit board (PCB). The top and bottom
layers are for signals, whereas Layer 2 and Layer 3 are used as
ground and a power plane, respectively. The PCB layout is
important to achieve good audio performance. The following
sections offer useful guidelines for operation of the board.
POWER SUPPLY CONNECTORS
The EVAL-ADAU1977Z board re5 V for the
ADAU1978 and ADAU1979 and may need an additional ±20 V
for testing the 10 V rms inputs of the ADAU1977 . Connect the
5 V power supply at J5 and J4. Connect the ±20 V power supply
at either TP3 (+20 V) or TP1 (−20 V). The +5 V power supply
must be capable of providing a 1 A current rating, and the
±20 V power supply must be capable of providing at least a
100 mA current rating. When the diagnostics feature is not
used, the ±20 V supply is not required.
INPUT CONNECTORS
The EVAL-ADAU1977Z has five 3.5 mm audio jack connectors
for analog inputs: J9, J17, J28, J38, and J47. The J9 connector is
used for generating line level inputs capable of 10 V rms, with a
common-mode level of 7 V for the
ADAU1977 . The J17, J28,
J38, and J47 connectors are used as Channel 1, Channel 2,
Channel 3, and Channel 4 line level inputs to the ADC,
respectively. All five inputs are differential.
OUTPUT CONNECTORS
The ADC digital output is available at J25 (unbuffered) and J26
(buffered). In addition, ADC digital output is available as a
2-channel Sony Philips digital interface format (SPDIF). J25 and
J26 are used for I
2 S or time division multiplex (TDM), serial
digital output. The U16 provides the SPDIF optical output, and
J35 provides the SPDIF coaxial output.
I 2 C/SPI CONTROL CONNECTOR
The J8 (10-way header) can be used for I 2 C/SPI serial port
communication for controlling the board. The supplied USB
interface board can be used for setting the device. The graphic
user interface (GUI) software is used along with the USB
interface board.
JUMPERS
The EVAL-ADAU1977Z board provides jumpers for setting this
board into various operating modes.
Table 1. Jumper Descriptions
Component No. Mnemonic Description
J1 MICBIAS SELECT AUX IN This jumper allows selecting either internal or external micbias for auxiliary input.
J2 CM SELECT AUX IN Used for setting the common mode level for auxiliary input.
J4 GND Ground or 0 V connection for the power supply.
J5 +5V +5 V connection for the power supply.
J8 USBi Connector for USBi board.
J9 AUX IN Connector for auxiliary input.
J10 IOVDD Selects the IOVDD 1.8 V or 3.3 V.
J11 IOVDD Ext/Int Selects the internal or external supply for IOVDD.
J12 VBAT Ext/Int Selects the internal or external supply for VBAT.
J13 3.3 V Ext/Int Selects the internal or external 3.3 V supply.
J14 AVDD Ext/Int Selects the internal or external AVDD supply for the ADAU1977 .
J15/J20 Input 1 Select Selects the input source for Channel 1.
J16 AVDD Current This jumper is used to measure the AVDD current.
J17 CH1 Input Connector for Channel 1 input.
J19 Input Short This jumper is used to short the ± Channel 1 input.
J21 Boost Current This jumper is used to measure the boost converter current.
J22 MICBIAS-CH1 Selects the internal or external micbias for Channel 1.
J24 Boost Switch This jumper is used to measure the boost switch current.
J25 ADC Output Header for connection to ADC digital pins.
J26 ADC Output Buffered Header for ADC digital output.
J27/J30 Input 2 Select Selects the input source for Channel 2.
J28 CH2 Input Connector for Channel 2 input.
J29 Input Short This jumper is used to short the ± Channel 2 input.
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