Datasheet

Evaluation Board User Guide UG-244
Rev. B | Page 3 of 16
EVALUATION BOARD HARDWARE
POWER SUPPLIES
The following power supplies are required.
Table 1. Power Supply Connections
Connector Nominal Comment
AV
DD
15 V Positive analog supply voltage.
10.8 V to 33 V range.
(Green LED D2 lights up when power
is supplied to AV
DD
.)
AV
SS
−15 V/
+0 V
Negative analog supply voltage.
+10.8 V to −26.4 V range, or 0 V for
the AD5757 or AD5755-1 in unipolar
supply mode.
AV
CC
5 V
DC-to-dc supply voltage.
4.5 V to 5.5 V range.
The AV
CC
input supplies all four on-
board dc-to-dc blocks and may draw
as much as 0.8 A peak current per
channel, depending on the
configuration (see the device data
sheet for more information).
DV
DD
3.3 V Supplied from the SDP connector.
2.7 V to 5.5 V range.
REFIN 5 V See Table 3 for selecting the
reference source: the AD575x
internal reference, the on-board
ADR02 reference, or externally
provided via the REFIN input.
Both analog AGND and PGND inputs are provided on the
board. The PGND input is for the ground of the dc-to-dc
converter circuitry, and a ground connection for the AV
CC
supply should be made at this point. The AGND and PGND
planes are connected at one location on the evaluation board.
The AGND and DGND planes are connected at one location
close to the AD5755, AD5755-1, or AD5757 device. Each
supply is decoupled to the relevant ground plane with
10 μF and 0.1 μF capacitors. Each device supply pin is also
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 3.
Default Link Option Setup
The default link options are listed in Table 2.
Table 2. Default Link Options
Link
No.
AD5755
Link Setup
AD5755-1
Link Setup
AD5757
Link Setup
LK0 Removed Removed Removed
LK1 Removed Removed Removed
LK2 Inserted Inserted Inserted
LK3 Inserted Inserted Inserted
LK4 Inserted Inserted Removed
LK5 Inserted Removed Removed
LK6 Inserted Inserted Removed
LK7 Inserted Removed Removed
LK8 Inserted Inserted Removed
LK9 Inserted Removed Removed
LK10 Inserted Inserted Removed
LK11 Inserted Removed Removed
LK12 Removed Removed Removed
LK13 Removed Removed Removed
LK14 Removed Removed Removed
LK15 Removed Removed Removed
Table 3. Link Options
Link No. Device Description
LK0, LK1, LK2 All Models These links select the voltage reference source (only one of these should be inserted at any one time).
LK0 selects the internal voltage reference of the AD575x as the voltage reference source.
LK1 selects an external voltage reference source that can be applied at Connector J7.
LK2 selects the on-board ADR02 as the voltage reference source. The ADR02 is supplied by the AV
DD
supply
and operates under the same input voltage range as the AV
DD
input of the AD575x, that is 9 V to 33 V.
LK3 All Models Powers the on-board ADR02 5 V reference by connecting the AV
DD
supply to the ADR02 supply pin.
LK4, LK6
LK10, LK8,
AD5755,
AD5755-1
These links connect the +V
SENSE
input to V
OUT
for Channel A, Channel B, Channel C, and Channel D, respectively.
When this link is inserted, the +V
SENSE
input is connected directly to the V
OUTx
pin.
When this link is removed, the +V
SENSE
input is left floating and should be connected to the high-side of the
load resistance external to the evaluation board.
LK5, LK7 LK9,
LK11,
AD5755 These links connect the +V
SENSE
input to V
OUT
for Channel A, Channel B, Channel C, and Channel D, respectively.
When this link is inserted, the +V
SENSE
input is connected directly to the V
OUT
pin.
When this link is removed, the +V
SENSE
input is left floating and should be connected to the high-side of the
load resistance external to the evaluation board.
LK12, LK13,
LK14, LK15
All Models These links allow connection of an external V
BOOST
supply. (Remove Resistors R43, R44, R17, and R20 to use this
feature.) When inserted, these connect the V
BOOST
pin of Channel A, Channel B, Channel C, and Channel D,
respectively, to the AV
DD
supply.
When removed, the V
BOOST
supplies are controlled by the dc-to-dc converter circuitry.