Introduction
13
SLAU579D – June 2014 – Revised August 2018
Copyright © 2014–2018, Texas Instruments Incorporated
ADC3xxxEVM and ADC3xJxxEVM
1.5.1
ADC32xxEVM
The ADC32xx-EVM boards can be operated in either ac-coupling or dc-coupling mode. To operate the
board in dc-coupling mode, a few modifications must be made. On the back side of the EVM, the
unpopulated pads must be populated with the devices listed on the
AMPLIFIER
schematic diagram (page
4) of the
ADC32XXXEVM-SCH_X.pdf
located in the
ADC32xx schematic design zip file
. This schematic
details the components needed for dc-coupling using the THS4541RGT and all required circuitry.
After the amplifier components are installed on the bottom of the ADC32xx-EVM, the resistors on the top
of the board must be altered to change the output from ac-coupled to dc-coupled.
shows the
three shared pad footprints per channel that must be modified. See
and the ADC32xx design files
to change the appropriate resistors.
Table 6. ADC32xxEVM AC-DC Coupling Resistor Swap
Mode
Install
Uninstall
AC-Coupled
R3, R4, R14R18, R142, R139
R135, R7, R120, R121R138, R20, R144,
R141
DC-Coupled
R135, R7, R120, R121R138, R20, R144,
R141
R3, R4, R14R18,R142, R139
Figure 8. ADC32xxVM Input Coupling Configuration Resistors