LTC1662 Linear Technology, LTC1662 Datasheet - Page 8

• Manufacturer Part Number: LTC1662
• Description: Ultralow Power/ Dual 10-Bit DAC in MSOP
• Manufacturer: Linear Technology

LTC1662
OPERATIO
Voltage Outputs
Each of the rail-to-rail output amplifiers contained in the
LTC1662 can typically source or sink up to 1mA
(V
of either supply when unloaded and have an equivalent
output resistance of 85 (typical) when driving a load to
the rails. The output amplifiers are stable driving capaci-
tive loads up to 1000pF.
8
NEGATIVE
CC
OFFSET
VOLTAGE
OUTPUT
= 5V). The outputs swing to within a few millivolts
Figure 2. 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
0V
U
INPUT CODE
(b)
VOLTAGE
OUTPUT
0
INPUT CODE
V
REF
512
(a)
= V
CC
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 2b.
Similarly, limiting can occur near full scale when the REF
pin is tied to V
(FSE = V
codes limits at V
limiting can occur if V
Offset and linearity are defined and tested over the region
of the DAC transfer function where no output limiting can
occur.
OS
1023
+ GE) is positive, the output for the highest
CC
. If V
CC
as shown in Figure 2c. No full-scale
REF
REF
= V
is less than V
V
REF
CC
INPUT CODE
= V
and the DAC full-scale error
(c)
CC
CC
REF
– FSE.
= V
CC
OUTPUT
VOLTAGE
POSITIVE
FSE
1662 F02