Data Sheet DAC8412/DAC8413
Rev. G | Page 17 of 20
The 0.2 μF bypass capacitors shown at the reference inputs in
Figure 40 should be used whenever ±10 V references are used.
Applications with single references or references to ±5 V may
not require the 0.2 μF bypassing. The 6.2 Ω resistor in series
with the output of the reference amplifier keeps the amplifier
from oscillating with the capacitive load. This 6.2 Ω resistor has
been found to be large enough to stabilize this circuit. Larger
resistor values are acceptable, provided that the drop across the
resistor does not exceed V
BE
. Assuming a minimum V
BE
of 0.6 V
and a maximum current of 2.75 mA, then the resistor should be
under 200 Ω for the loading of a single DAC8412.
Using two separate references is not recommended. Having two
references can cause different drifts with time and temperature;
whereas with a single reference, most drifts track.
Unipolar positive full-scale operation can usually be set with a
reference with the correct output voltage. This is preferable to
using a reference and dividing down to the required value. For a
10 V full-scale output, the circuit can be configured as shown in
Figure 41. In this configuration, the full-scale value is set first by
adjusting the 10 kΩ resistor for a full-scale output of 9.9976 V.
10k
0.01µF
10µF
–15V
ND
TRIM
OUTPUT
VOLTAGE
REFERENCE
0.2µF
V
REFL
V
REFH
DAC8412
OR
DAC8413
0.1µF
//10µF
ZERO TO –10V OPERATION
V
DD
V
SS
00274-042
Figure 41. Unipolar –10 V Operation
Figure 41 shows the DAC8412 configured for –10 V to 0 V
operation. A –10 V full-scale output voltage reference is
connected directly to V
REFL
for the reference voltage.
SINGLE +5 V SUPPLY OPERATION
For operation with a 5 V supply, the reference voltage should be
set between 1.0 V and 2.5 V for optimum linearity. Figure 42
shows a REF43 used to supply a 2.5 V reference voltage. The
headroom of the reference and DAC are both sufficient to support
a 5 V supply with ±5% tolerance. V
DD
and V
LOGIC
should be
connected to the same supply. Separate bypassing to each pin
should also be used.
5
INPUT
OUTPUT
GND
TRIM
REF43
ZERO TO 2.5V OPERATION
SINGLE 5V SUPPLY
10kΩ
0.2µF
V
REFL
V
REFH
DAC8412
OR
DAC8413
0.1µF
//10µF
10µF 0.01µF
V
DD
V
SS
00274-043
Figure 42. +5 V Single-Supply Operation
