Hardware Setup - Linear Technology DC1485A Demo Manual

DEMO MANUAL DC1485A

harDware setup

Jumpers
MSPAN: Manual Span Control Pin. MSPAN is used to
configure the LTC2757 for operation in a single, fixed
output range. If MSPAN is high it will be configured for
single-span use. If MSPAN is low it will be set through the
QuikEval Software. Default position is 0 (low).
S0, S1, S2: Used to set the fixed output range if MSPAN
is high. Default position is 0, 0, 0 (0V to 5V).
S2
0
0
0
0
1
1
REFADJ: Gain Adjust Pin. If no adjustments are required,
select GND. Selecting EXT connects the pin to the turret
allowing external adjustment to null gain error or com-
pensate for reference errors.
RVOS: Offset adjustment for DAC. If no offset adjustment
is required, select GND. Selecting EXT connects the offset
pin to the turret allowing external adjustment of offset.
V : Select source for 5V V
CC
by onboard LT1236 reference (recommended). Set to REG
to be supplied by regulated supply from DC590 Controller
and remove the jumper to supply externally.
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S1 S0
0 0 0V to 5V
0 1 0V to 10V
1 0
1 1
0 0
0 1 –2.5V to 7.5V
supply. Set to 5V for supply
CC
Analog Connections (Turret Posts)
V : DAC Voltage Output.
OUT
V : DAC Reference Voltage. If the onboard LT1236 refer-
REF
ences are selected, the voltage may be measured at these
points. If a remote reference is selected, then an external
reference must be applied to these points.
RVOS: DAC Offset Adjust Input. Use only if RVOS jumper
is set to EXT. Nominal input range is ±5V.
SPAN
REFADJ: Gain Adjust Pin. This voltage-control pin can be
used to null gain error or to compensate for reference er-
rors. The gain error change expressed in LSB is the same
±5V for any output range.
±10V
Power and Ground Connections
±2.5 V
Analog Power: The 15V, –15V and GND turret posts are
the analog supplies for the internal DAC amplifiers. These
should be connected to a well regulated, low noise power
supply.
V : Connection to V
CC
for V jumper.
CC
Grounding: Separate power and signal grounds are pro-
vided. Signal GND is the turret closest to V
for measurement ground and output return. Power GND
is between AMP V
. See schematic and description
CC
OUT
+ –
and AMP V turrets.
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