Datasheet

12
LTC1655/LTC1655L
TYPICAL APPLICATIONS
U
This circuit shows how to make a bipolar output 16-bit
DAC with a wide output swing using an LTC1655 and an
LT1077. R1 and R2 resistively divide down the LTC1655
output and an offset is summed in using the LTC1655
onboard 2.048V reference and R3 and R4. R5 ensures that
the onboard reference is always sourcing current and
never has to sink any current even when V
OUT
is at full
scale. The LT1077 output will have a wide bipolar output
swing of –4.096V to 4.096V as shown in the figure below.
With this output swing 1LSB = 125µV.
A Wide Swing, Bipolar Output 16-Bit DAC
CLK
D
IN
CS/LD
µP
0.1µF
V
CC
V
OUT
GND V
REF
R1
100k
1%
5V
LTC1655
1655/55L TA05
–
+
LT1077
5V
–5V
R2
200k
1%
R3
100k
1%
R5
100k
1%
R4
200k
1%
(2)(D
IN
)(4.096)
65536
V
OUT
:
D
IN
V
OUT
4.096
–4.096
32768
0
65535
TRANSFER CURVE
– 4.096V
1
6
8
5
7
2
3
6
7
4
3
2