LTC1657/LTC1657L
18
1657lfa
For more information www.linear.com/LTC1657
LINEAR TECHNOLOGY CORPORATION 1999
LT 0715 REV A • PRINTED IN USA
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507
●
www.linear.com/LTC1657
RELATED PARTS
TYPICAL APPLICATION
This circuit shows how to measure negative offset. Since
LTC1657/LTC1657L operate on a single supply, if their
offset is negative, the output for code 0 limits at 0V. To
Although LTC1657 output is up to 4.096V with its internal
reference, higher voltages can be achieved with the help
of another op amp. The following circuit shows how to
PART NUMBER DESCRIPTION COMMENTS
LTC1446(L) Dual 12-Bit V
OUT
DACs in SO-8 Package V
CC
= 5V (3V), V
OUT
= 0V to 4.095V (0V to 2.5V)
LTC1450(L) Single 12-Bit V
OUT
DACs with Parallel Interface V
CC
= 5V (3V), V
OUT
= 0V to 4.095V (0V to 2.5V)
LTC1458(L) Quad 12-Bit Rail-to-Rail Output DACs with Added Functionality V
CC
= 5V (3V), V
OUT
= 0V to 4.095V (0V to 2.5V)
LTC
1650 Single 16-Bit V
OUT
Industrial DAC in 16-Pin SO V
CC
= ±5V, Low Power, Deglitched, 4-Quadrant Multiplying V
OUT
LTC1654 Dual 14-Bit V
OUT
DAC Programmable Speed/Power, SO-8 Footprint
LTC1655(L) Single 16-Bit V
OUT
DAC with Serial Interface in SO-8 V
CC
= 5V (3V), Low Power, Deglitched, V
OUT
= 0V to 4.096V
(0V to 2.5V)
LTC1658 Single 14-Bit V
OUT
DAC in MSOP Package 2.7V to 5.5V Operation, Low Power
Negative Offset Measurement
measure this negative offset, a negative supply is needed,
connect resistor R1 as shown in the figure. The output
voltage is the offset when code 0 is loaded in.
increase the output swing of LTC1657 by using an LT1218.
As shown in the configuration, the output of LTC1657 is
amplified by 8 for an output swing of 0V to 32.768V, or a
convenient 0.5mV
/LSB.
A Higher Voltage Output DAC
65535
0.1µF
5V
1657 TA07
V
OUT
= 1 +
0.1µF
36V
(D
IN
)(4.096)
65536
R2
R1
DATA (0:15)
CSLSB
CSMSB
WR
LDAC
CLR
GND
V
CC
REFOUTREFHI
REFLOX1/X2
LTC1657
µP
7
6
4
26 21 20
22 23 24
325
5:19
2
3
1
28
27
2
V
OUT
–
+
LT1218
( )
R1
1k
1%
R2
6.98k
1%
D
IN
32.768 (V)
0
TRANSFER CURVE
V
OUT
0.1µF
5V
–5V
1657 TA06
DATA (0:15)
CSLSB
CSMSB
WR
LDAC
CLR
GND
V
CC
REFOUTREFHI
REFLOX1/X2
LTC1657/LTC1657L
µP
26 21 20
22 23 24
25
5:19
2
3
1
28
27
V
OUT
R1
100k
