UG-459 Datasheet, PDF (3/12 Pages) Analog Devices – Full-featured evaluation board

Evaluation Board User Guide
EVALUATION BOARD HARDWARE
POWER SUPPLIES
To use the evaluation board with the SDP board, a 6 V power
supply is required, which is connected to Connector J3. The
evaluation board can be used without the SDP board. In this case,
the J1 and J2 connectors are used as the power supply inputs.
Both AGND and DGND inputs are provided on the board. The
AGND and DGND planes are connected at one location close
to the AD568x(R). It is recommended that AGND and DGND
not be connected elsewhere in the system to avoid ground loop
problems.
All supplies are decoupled to ground with 10 µF tantalum and
0.1 µF ceramic capacitors.
Table 1. Power Supply Connectors
Connector Number
Voltage
J1
External, V_LOGIC supply
J2
Analog power supply, V_DD
J3
6 V board positive power supply
UG-459
LINK OPTIONS
A number of link options are incorporated in the evaluation
board and must be set for the required operating conditions
before using the board. The functions of these link options are
described in detail in Table 3. Table 2 lists the positions of the
different links controlled by PC, via the USB port, and the SDP
board in single-supply mode is required.
Table 2. Link Options Setup for SDP Control (Default)
Link Number
Option
LK1
A
LK2
A
LK3
C
LK4
B
LK5
A
LK6
B
Table 3. Link Functions
Link Number Option
LK1
This link selects the DAC analog voltage source.
Position A selects the internal voltage source (INT_VDD) from the ADP3331.
Position B selects an external supply voltage (EXT_VDD).
LK2
This link selects the DAC digital voltage source.
Position A selects the digital voltage source from the SDP board (V_IO).
Position B selects an external digital supply voltage (EXT_VLOGIC).
LK3
This link selects the reference source.
Position A selects the on-board 2.5 V reference as the reference source. Do not use this option with the AD5686R/AD5684R.
Position B selects the on-board 5 V reference as the reference source. Do not use this option with the AD5686R/AD5684R.
Position C selects the internal reference of the AD5686R/AD5684R as the reference source for the AD5686/AD5684.
Position D selects an off board voltage reference via the EXT_REF connector.
LK4
This link selects the gain setting of the AD5686/AD5684 (not populated).
Position A selects gain of 2.
Position B selects gain of 1.
LK5
This link selects the gain setting of the AD5686R/AD5684R.
Position A selects gain of 2.
Position B selects gain of 1.
LK6
This link selects whether the AD5686R/AD5684R or AD5686/AD5684 is accessed by the software.
Position A selects the AD5686/AD5684.
Position B selects the AD5686R/AD5684R.
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