UG-442
Evaluation Board User Guide
Rev. C | Page 4 of 16
Table 4. Link Options
Link No.
Description
LK1
This link selects the state of the CLEAR SELECT pin (when the evaluation board is configured for external control).
Position A ties the CLEAR SELECT pin to 0 V.
Position B ties the CLEAR SELECT pin to DV
CC
.
LK2
This link selects the state of the CLEAR pin (when the evaluation board is configured for external control).
Position A ties the CLEAR pin to 0 V.
Position B ties the CLEAR pin to DV
CC
.
LK3
This link selects the state of the DV
CC
SELECT pin.
When inserted, the DV
CC
SELECT pin is tied to 0 V, disabling the internal supply; an external supply must be connected to the
DV
CC
pin via LK17.
When removed, the DV
CC
SELECT pin is unconnected, enabling the internal supply. Removing LK3 eliminates the need for an
external digital supply; therefore, LK17 can also be removed.
LK4
This link selects the negative supply voltage for AV
SS
.
Position A selects 0 V as the negative supply voltage (unipolar voltage output operation).
Position B selects the AV
SS
connection of J2 as the negative supply voltage (bipolar voltage output operation).
LK5
This link selects how the I
OUT
current loop return is connected to ground on the evaluation board.
Position A connects the I
OUT
current loop return directly to ground.
Position B connects the I
OUT
current loop return input to GND through a 51 Ω resistor. The high side of the resistor is
connected to the V
IN
1 input of the on-board ADC (
AD7321
), allowing readback to the PC of the output current.
LK6
This link selects the 5 V power supply source for the digital circuitry.
Position A selects the USB port as the 5 V digital circuitry power supply source.
Position B selects J7 as the 5 V digital circuitry power supply source.
LK7
This link selects whether the
AD5422
evaluation board is controlled by the PC via the USB port or by an external source via J8.
Position A selects the evaluation board to be controlled by the PC via the USB port.
Position B selects the evaluation board to be controlled by an external source via J8.
LK8
This link selects the digital supply voltage value for the
AD5422
and the on-board ADC (U6).
Position A selects 5 V as the supply value.
Position B selects 3.3 V as the supply value.
LK9
This link selects the positive power supply source for U2 and U6.
Position A selects the AV
DD
input as the positive power supply source (use only if the power supply applied to AV
DD
is less
than 16.5 V).
Position B selects the V+ input as the positive power supply source (use if the power supply applied to AV
DD
input is greater
than 16.5 V). A power supply voltage of 10.8 V to 16.5 V can be applied to V+.
LK10
This link is used to enable/disable the external boost transistor.
When this link is inserted, the external boost transistor is disabled.
When this link is removed, the external boost transistor is enabled.
LK11
This link connects the −V
SENSE
input to ground.
When this link is inserted, the −V
SENSE
input is connected directly to ground.
When this link is removed, the −V
SENSE
input is left floating and should be connected to the low side of the load resistance
external to the evaluation board.
LK12
This link connects the +V
SENSE
input to V
OUT
.
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 connected to V
OUT
through a 47 kΩ resistance (to prevent the integrated
voltage amplifier loop from opening).
LK13
This link connects the I
OUT
connector directly to the GND connector.
When this link is inserted, the I
OUT
connector is connected directly to the GND connector.
When this link is removed, the I
OUT
connector is disconnected from the GND connector (an external load must be connected).
LK14
This link connects the V
OUT
output of the
AD5422
to the V
IN
0 input of the on-board ADC (
AD7321
).
When this link is inserted, the voltage at the V
OUT
pin can be read back to the PC.
When this link is removed, the voltage at the V
OUT
pin is disconnected from the on-board ADC input.
