Datasheet

13
LTC1654
1654fb
This circuit shows how to use an LTC1654 and an LT
®
1077
to make a wide bipolar output swing 14-bit DAC with an
offset that can be digitally programmed. V
OUTA
, which can
be set by loading the appropriate code for DAC A, sets the
offset. As this value changes, the transfer curve for the
output moves up and down as illustrated in the graph
below.
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
X
1
/X
1/2
B
CLR
SCK
SDI
CS/LD
DGND
SDO
X
1
/X
1/2
A
V
CC
V
OUT B
REFHI B
REFLO B
AGND
REFLO A
REFHI A
V
OUT A
LTC1654
0.1µF
49.9k
1%
5V
1654 TA02
µP
100k
1%
49.9k
1%
V
OUT
2 (V
OUTB
– V
OUTA
)
15V
–15V
100k
1%
–
+
LT1077
V
OUT
0
V
OUTA
≅ 0V
V
OUTA
≅ 2.5V
V
OUTA
≅ 5V
CODE
5
1654 TA03
–5
–10
10
16383
A Wide Swing, Bipolar Output 14-Bit DAC with Digitally Controlled Offset
TYPICAL APPLICATIO S
U