LTC1659 Linear Technology, LTC1659 Datasheet - Page 9

• Manufacturer Part Number: LTC1659
• Description: 12-Bit Rail-to-Rail Micropower DAC in MSOP Package
• Manufacturer: Linear Technology

APPLICATIONS
Rail-to-Rail Output Considerations
In any rail-to-rail DAC, the output swing is limited to
voltages within the supply range.
If the DAC offset is negative, the output for the lowest
codes limits at 0V as shown in Figure 1(b).
Similarly, limiting can occur near full scale when the REF
pin is tied to V
(FSE) is positive, the output for the highest codes limits at
NEGATIVE
OFFSET
VOLTAGE
OUTPUT
0V
CC
. If V
U
REF
Figure 1. Effects of Rail-to-Rail Operation on a DAC Transfer Curve
(a) Overall Transfer Function
(b) Effect of Negative Offset for Codes Near Zero Scale
(c) Effect of Positive Full-Scale Error for Input Codes Near Full Scale When V
= V
INPUT CODE
INFORMATION
U
CC
(b)
and the DAC full-scale error
W
VOLTAGE
OUTPUT
0
U
INPUT CODE
V
REF
2048
(a)
= V
V
occur if V
Offset and linearity are defined and tested over the region
of the DAC transfer function where no output limiting can
occur.
CC
CC
as shown is Figure 1(c). No full-scale limiting can
REF
4095
is less than V
V
CC
REF
INPUT CODE
REF
= V
– FSE.
(c)
CC
= V
CC
LTC1659
OUTPUT
VOLTAGE
POSITIVE
FSE
1659 F01
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