LTC1658CS8PBF 参数 Datasheet PDF下载

LTC1658

APPLICATIONS INFORMATION

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 1b.

Similarly, limiting can occur near full scale when the REF

pin is tied to V

CC

. If V

REF

= V

CC

and the DAC full-scale error

(FSE) is positive, the output for the highest codes limits at

V

CC

as shown in Figure 1c. No full-scale limiting can occur

if V

REF

is less than V

CC

– FSE.

Offset and linearity are defined and tested over the region

of the DAC transfer function where no output limiting can

occur.

OUTPUT

VOLTAGE

0

OUTPUT

VOLTAGE

0V

NEGATIVE

OFFSET

INPUT CODE

(b)

1658 F01

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

REF

= V

CC

8

U

W

U

U

V

REF

= V

CC

POSITIVE

FSE

OUTPUT

VOLTAGE

INPUT CODE

(c)

V

REF

= V

CC

8192

INPUT CODE

(a)

16383