LTC1654
TYPICAL APPLICATIO S
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. VOUTA, 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.
A Wide Swing, Bipolar Output 14-Bit DAC with Digitally Controlled Offset
5V
LTC1654
0.1µF
1
16
X1/X1/2 B
VCC
2
15
CLR
VOUT B
µP
3
SCK
4
SDI
14
REFHI B
13
REFLO B
49.9k
1%
15V
+
5
CS/LD
6
DGND
12
AGND
11
REFLO A
100k
LT1077
1%
–
VOUT
2 (VOUTB – VOUTA)
7
SDO
10
REFHI A
8
9
X1/X1/2 A VOUT A
49.9k
–15V
100k
1654 TA02
1%
1%
10
VOUTA ≅ 0V
5
VOUTA ≅ 2.5V
0
CODE
VOUTA ≅ 5V
16383
–5
–10
1654 TA03
1654fb
13