Evaluation Board Hardware; Power Supplies; Link Options - Analog Devices UG-442 User Manual

Evaluation Board User Guide

EVALUATION BOARD HARDWARE

POWER SUPPLIES

The following external supplies must be provided:
•
5 V between the 5 V and 0 V inputs for the digital supply
of the AD5422 and digital circuitry. Alternatively, place
LK6 in Position A to power the digital circuitry from the
USB port (default).
•
10.8 V to 40 V between the AV
analog supply of the AD5422.
•
0 V to −26.4 V between the AV
negative analog supply of the AD5422. (This is only required
if a bipolar output voltage range is programmed; otherwise,
the negative supply of the
GND by placing LK4 in Position A.)
•
10.8 V to 16.5 V between the V+ and GND inputs for the
analog supply of the AD7321
converter [ADC]) and ADR435
If the analog supply connected to the AV
16.5 V, the AD7321 and
by placing LK9 in Position A, and the V+ input can be left
unconnected.
•
0 V to −16.5 V between the V− and GND inputs for the
negative analog supply of the
the negative analog supply connected to the AV
less than (magnitude) −16.5 V, the
from this by placing LK16 in Position A, and the V− input
can be left unconnected.
The analog and digital planes are connected at one location, close
to the AD5422. It is recommended not to connect GND and
DGND elsewhere in the system to avoid ground loop problems.
Each supply is decoupled to the relevant ground plane with 10 µF
and 0.1 µF capacitors. Each device supply pin is again decoupled
with a 10 µF and 0.1 µF capacitor pair to the relevant ground plane.
Excessive Power Supply
If a power supply in excess of 16.5 V is connected to the AV
input, LK9 must be in Position B to prevent potential damage to the
5 V voltage reference and to the ADC (see U2 and U6, respectively,
in Figure 6). However, if a power supply in excess of −16.5 V is to
be connected to the AV input, LK16 must be in Position B to
SS
prevent potential damage to the ADC.

LINK OPTIONS

The position of LK7 configures the board for either PC control via
the USB port (default setup) or for control by an external source
via J8. Set the link options on the evaluation board for the required
operating setup before using the board. The functions of the link
options are described in Table 4.
and GND inputs for the
DD
and GND inputs for the
SS
AD5422 can be connected to
(on-board analog-to-digital
(on-board voltage reference).
input is less than
DD
ADR435 can be powered from this
AD7321 (on-board ADC). If
input is
SS
AD7321 can be powered
Default Link Option Setup
The default setup is for control by the PC via the USB port. The
default link options are listed in Table 1.
Table 1. Link and Switch Options for PC Control
Link No.
LK1
LK2
LK3
LK4
LK5
LK6
LK7
LK8
LK9
LK10
LK11
LK12
LK13
LK14
LK15
LK16
LK17
LK18
Connector J8 Pin Descriptions
Table 2. Connector J8 Pin Configuration
2 4
1 3
1 LK7 must be in Position B to enable the use of J8.
Table 3. Connector J8 Pin Descriptions
Connector J8 Pin No.
1
2
DD
3
4
5
6
7
8
9
10
Rev. C | Page 3 of 16
UG-442
Option
A
A
Inserted
B
B
A
A
A
A
Inserted
Inserted
Inserted
Inserted
Inserted
C
A
Inserted
Inserted
1
6 8
5 7
Function
SDO
CLEAR SELECT
DGND
CLEAR
DGND
FAULT
SDIN
DGND
SCLK
LATCH
10
9