EVAL-AD7177-2SDZ User Guide
UG-849
Rev. 0 | Page 7 of 14
POWER SUPPLY CONFIGURATIONS
Single Supply (Regulated)
There are two available power supply options for the single
supply (regulated) configuration.
•
An ac-to-dc adapter (included) connected to J5. Set LK2 to
Position B.
•
A bench top power supply connected to J3. Set LK2 to
Position A, and ensure that AVSS = AGND = 0 V.
Set all other links and solder links to the default settings as
outlined in Table 1.
Single Supply (Unregulated)
To set up the evaluation board, use the following procedure:
1.
Move SL2 and SL5 to Position A.
2.
Connect the two terminals of J9 labeled AGND and AVSS.
3.
Connect 0 V (GND) to J9 at the terminal labeled AGND.
4.
Connect 5 V to J9 at the terminal labeled AVDD.
5.
Connect 3.3 V to J9 at the terminal labeled IOVDD.
6.
Connect the 7 V to 9 V input to J5.
Set all other links and solder links to the default settings as
outlined in Table 1.
Split Supply (Regulated)
To set up the evaluation board, use the following procedure:
1.
Remove R49 to R51. These links connect AVSS to AGND.
2.
Insert a 0 Ω resistor for R85.
3.
Set LK1 to Position B, which sets the input to the power
monitor circuitry to work with the lower AVDD1 supply
of 2.5 V.
4.
Connect a bench top power supply to J5 and set LK2 to
Position B.
5.
Set LK1 to Position B, which sets the input to the power
monitor circuitry to work with the lower AVDD1 supply
of 2.5 V.
Set all other links and solder links to the default settings as
outlined in Table 1.
Split Supply (Unregulated)
To set up the evaluation board, use the following procedure:
1.
Move SL2, SL3 to Position B and SL5 to Position A.
2.
Remove R49 to R51.
3.
Connect 0 V (GND) to J9 at the terminal labeled AGND.
4.
Connect 2.5 V to J9 at the terminal labeled AVDD.
5.
Connect −2.5 V to J9 at the terminal labeled AVSS.
6.
Connect 3.3 V to J9 at the terminal labeled IOVDD.
7.
Connect 7 V to 9 V to J5.
8.
Set LK1 to Position B. This sets the input to the power
monitor circuitry to work with the lower AVDD1 supply
of 2.5 V.
Set all other links and solder links set to the default settings as
outlined in Table 1.
ANALOG INPUTS
The primary analog inputs of the
EVAL-AD7177-2SDZ
evaluation board can be applied in two separate ways.
•
J6 connector on the left side of the board
•
A0 to A4 SMB/SMA footprints on the evaluation board
The analog inputs route directly to the associated analog input
pins on the
AD7177-2
, provided that the LK5 to LK9 links (on-
board noise test) are removed. The
AD7177-2
evaluation
software is set up to analyze dc inputs to the ADC. The
AD7177-2
input buffers work for dc input signals.
REFERENCE OPTIONS
The
EVAL-AD7177-2SDZ
evaluation board includes an external
5 V reference, the
ADR445
. The
AD7177-2
includes an internal
2.5 V reference. The default operation is to use the external
reference input, which is set to accept the 5 V
ADR445
on the
evaluation board.
