Datasheet
Evaluation Board User Guide UG-256
Rev. A | Page 3 of 20
EVALUATION BOARD HARDWARE
POWER SUPPLIES
The following external supplies must be provided:
• 5 V between the V
CC
and DGND inputs for the digital
supply of the AD5780. Alternatively, place Link 1 in
Position A to power the digital circuitry from the USB
port via the SDP board (default).
• 7.5 V to 16.5 V between the V
DD
and AGND inputs for
the positive analog supply of the AD5780.
• −2.5 V to −16.5 V between the V
SS
and AGND inputs for
the negative analog supply of the AD5780.
The analog and digital planes are connected at one location, close
to the AD5780. To avoid ground loop problems, it is recommended
not to connect AGND and DGND elsewhere in the system.
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.
LINK OPTIONS
The link options on the evaluation board should be set for the
required operating setup before using the board. The functions
of the link options are described in Table 5.
Default Link Option Setup
The default link options are listed in Table 1. By default, the
board is configured with V
REFP
= +10 V and V
REFN
= −10 V for
a ±10 V output range.
Table 1. Default Link Options
Link No. Option
LK1 A
LK2 B
LK3
A
LK4 Removed
LK5 Removed
LK6 Removed
LK7 Removed
LK8
C
LK9 Inserted
LK11 Inserted
Connector J3 Pin Descriptions
Table 2. Connector J3 Pin Configuration
9 7 5 3 1
10
8
6
4
2
Table 3. Connector J3 Pin Descriptions
Pin No. Description
1 SDO
2
RESET
3 DGND
4
CLR
5 DGND
6
LDAC
7 SDIN
8 DGND
9 SCLK
10
SYNC
ON-BOARD CONNECTORS
There are nine connectors on the AD5780 evaluation board
PCB as outlined in Table 4.
Table 4. On-Board Connectors
Connector Function
J1 Digital power supply connector
J2
Analog power supply connector
J3 Digital interface pin header connector
J4 SDP board connector
VOUT DAC output connector
VOUT_BUF Buffered DAC output connector
VREF +5 V external reference voltage input connector
(+10 V, +5 V, −10 V, and −5 V reference voltages are
generated from this +5 V input or on-board
ADR4550)
VREFN DAC negative reference input connector
VREFP DAC positive reference input connector