ltc1654cgn-trpbf Linear Technology Corporation, ltc1654cgn-trpbf Datasheet - Page 11

• Manufacturer Part Number: ltc1654cgn-trpbf
• Description: Ltc1654 - Dual 14-bit Rail-to-rail Dac In 16-lead Ssop Package
• Manufacturer: Linear Technology Corporation

APPLICATIO S I FOR ATIO
Rail-to-Rail Output Considerations
Rail-to-rail DACs take full advantage of the supply range
available to them, but cannot produce output voltages
above V
If REFLO is tied to GND, the output for the lowest codes
may limit at 0V, as shown in Figure 2b. Similarly, limiting
can occur near full scale if the REFHI pin is tied to V
shown in Figure 2c.
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
CC
or below ground. See Figure 2a.
NEGATIVE
OFFSET
VOLTAGE
OUTPUT
0V
U
U
INPUT CODE
(b)
W
VOLTAGE
OUTPUT
0
U
Table 2. Low Code k
V
REF
CC
= V
1/2
, as
1
Note: V
CC
INPUT CODE
8192
4.096 2.048
(a)
128
256
V
REFLO
REFHI
The offset, gain error and linearity of the LTC1654 are
defined and tested in output ranges that avoid limiting.
The low code k
the code which gives a nominal output of 32mV above
ground; see Table 2.
256
512
, V
= O
L
16383
L
used in these measurements is defined as
V
REF
INPUT CODE
= V
CC
(c)
OUTPUT
VOLTAGE
POSITIVE
FSE
1654 F02
LTC1654
REF
= V
11
CC
1654fb