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0

−0.2

−0.4

−0.6

−0.8

−1.0

−1.2

−1.4

−1.6

−1.8

−2.0

−40

−20

0

20

40

60

80

100

120

Temperature (

_C)

V

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0

−40

−20

0

20

40

60

80

100

120

Temperature (

_C)

V

Theory of Operation

R

R

R

R

2R

2R

2R

2R

R

FB

I

OUT2

I

OUT 1

2R

V

REF

DB0

(LSB)

DB9

DB10

DB11

(MSB)

V

OUT

CODE

4096

(1)

DAC7811

SBAS337 – APRIL 2005

TYPICAL CHARACTERISTICS: V

At T

GAIN ERROR

OUTPUT LEAKAGE

vs TEMPERATURE

vs TEMPERATURE

Figure 23.

Figure 24.

The DAC7811 is a single channel current output, 12-bit digital-to-analog converter (DAC). The architecture,

illustrated in Figure 25, is an R-2R ladder configuration with the three MSBs segmented. Each 2R leg of the

potential by the use of an external I/V converter op amp. The R-2R ladder is connected to an external reference

impedance to the external reference of 10 k

Ω± 20%. The external reference voltage can vary in a range of –15 V

Figure 25. Equivalent R-2R DAC Circuit

Equation 1:

also change. Because of this, the external I/V converter op amp must have a sufficiently low offset voltage such

large offset voltages can produce INL errors in the transfer function of the DAC7811 due to offset modulation

versus DAC code.

9