ltc1659cs8-trpbf Linear Technology Corporation, ltc1659cs8-trpbf Datasheet - Page 9

• Manufacturer Part Number: ltc1659cs8-trpbf
• Description: Ltc1659 - 12-bit Rail-to-rail Micropower Dac In Msop Package
• Manufacturer: Linear Technology Corporation

APPLICATIONS INFORMATION
Rail-to-Rail Output Considerations
In any rail-to-rail DAC, the output swing is limited to volt-
ages within the supply range.
If the DAC offset is negative, the output for the lowest
codes limits at 0V as shown in Figure 1b.
Similarly, limiting can occur near full scale when the REF
pin is tied to V
NEGATIVE
OFFSET
VOLTAGE
OUTPUT
0V
CC
. If V
Figure 1. Effects of Rail-to-Rail Operation on a DAC Transfer Curve
(1a) Overall Transfer Function
(1b) Effect of Negative Offset for Codes Near Zero Scale
(1c) Effect of Positive Full-Scale Error for Input Codes Near Full Scale When V
REF
INPUT CODE
= V
(1b)
CC
and the DAC full-scale
VOLTAGE
OUTPUT
0
INPUT CODE
V
REF
2048
(1a)
= V
error (FSE) is positive, the output for the highest codes
limits at V
can occur if V
Offset and linearity are defi ned and tested over the region
of the DAC transfer function where no output limiting can
occur.
CC
CC
4095
as shown is Figure 1c. No full-scale limiting
REF
is less than V
V
REF
REF
INPUT CODE
= V
(1c)
= V
CC
CC
CC
– FSE.
LTC1659
OUTPUT
VOLTAGE
POSITIVE
FSE
1659 F01
1659fa
9