UG-1135
Rev. 0 | Page 25 of 45
HARDWARE DESCRIPTION
ICs
Table 5. IC Descriptions
Reference Functional
Name
Description
U1
Everlight PLT133/T8 optical transmitter
S/PDIF optical (TOSLINK) output.
U2
Everlight PLT133/T10W optical receiver
S/PDIF optical (TOSLINK) input.
U3
audio processor
Acts as an audio hub for all audio inputs and outputs in the system
and performs digital signal processing on those input and output
signals.
U4
audio codec
Converts analog audio inputs to digital data for the
processor
and takes digital data back from the
to convert to analog
audio outputs signals.
U5
LDO voltage regulator
Accepts the unregulated dc supply voltage between 5 V and 7 V that
is provided on Connector J4 and regulates the supply voltage down
to 3.3 V.
U7
reset supervisor
Generates a master reset signal for the
the RESET push-button (S1) is pressed or if
sends a reset
command via the
U10
Microchip 25AA1024 serial EEPROM
Stores data, allowing the
to perform a self boot operation.
U6, U8, U9, U11,
U12, U13, U15, U17
dual, low power, low noise, and
low distortion rail-to-rail output amplifier
Implements the analog audio filtering required for the stereo line inputs
and outputs.
U14
74ACT04SC hexadecimal inverter
Buffers logic signals and drives status LEDs.
STATUS LEDs
Table 6. LED Descriptions
Reference Functional
Name
Description
D1
USB
connected
Illuminates when the
is recognized by Windows after the
is connected to Control Port J1 and the
USB 2.0 port of the computer.
D2
3.3 V supply
status LED
Illuminates when the output of the
LDO voltage regulator has
reached a level sufficient to exceed the V
IH
logic high input level of the 74ACT04SC inverter. (When this LED
is illuminated, it does not guarantee that the LDO output is 3.3 V. It only shows that the LDO output is about
2 V or greater. To perform more detailed measurements of the LDO output level, check the voltage on the
A_3V3 test point, TP1.)
D3
MP9 general-
purpose LED
Illuminates when the status of the
LRCLK_OUT3/MP9 pin is set to logic high by the
D4
MP5 general-
purpose LED
Illuminates when the status of the
LRCLK_OUT1/MP5 pin is set to logic high by the
D5
MP11 general-
purpose LED
Illuminates when the status of the
LRCLK_IN1/MP11 pin is set to logic high by the
D6
Master reset
status LED
Illuminates when the master reset signal being generated by the ADM811TARTZ reset supervisor IC is logic
low, which puts the
into hardware reset. LED D3 does not illuminate when the
master reset signal is logic high and the
are out of reset.
D7
Self boot
status LED
Illuminates when the self boot switch (Position 1 of Switch S3) is set to the on position, signifying that a self boot
operation is to be executed on the rising edge of the
is powered
up. LED D2 does not illuminate when the self boot slide switch (S2) is set to the disabled, which signifies that
no self boot operation is to occur.