Datasheet
REV. B
DAC8043A
–8–
C00272–0–4/06 (B)
reference, the DAC output will provide a proportional dc voltage
output according to the transfer equation:
V
OUT
= –D/4096 × V
REF
where D is the decimal data loaded into the DAC register and
V
REF
is the externally applied reference voltage source.
V
REF
I
OUT
GND
OP77
2R
R
R
FB
V
AC
V
DD
R
FB
ⴞ10V
P
V
OUT
2R
DIGITAL INPUTS OMITTED FOR CLARITY
10pF
Figure 19. Unipolar (2-Quadrant) Operation
BIPOLAR 4-QUADRANT MULTIPLYING
Figure 20 shows a suggested circuit to achieve 4-quadrant mul-
tiplying operation. The summing amplifier multiplies V
OUT1
by
2, and offsets the output with the reference voltage so that a
midscale digital input code of 2048 places V
OUT2
at zero volts.
The negative full-scale voltage will be V
REF
when the DAC is
loaded with all zeros. The positive full-scale output will be
–(V
REF
– 1 LSB) when the DAC is loaded with all ones. Thus
the digital coding is offset binary. The voltage output transfer
equation for various input data and reference (or signal) values
follows:
V
OUT2
= (D/2048 – 1) × –V
REF
where D is the decimal data loaded into the DAC register and
V
REF
is the externally applied reference voltage source.
Precision resistors will be necessary to avoid ratio errors. Other-
wise trimming will be required to achieve full accuracy specifica-
tions available from the DAC8043A device. See the various
Analog Devices Digital Potentiometer products for automated
trimming solutions (e.g., the AD5204 for low voltage applica-
tions or the AD7376 for high voltage applications).
(0V TO –V
REF
)
V
REF
I
OUT
GND
2R
R
R
FB
V
AC
V
DD
R
FB
ⴞ10V
P
V
OUT1
2R
DIGITAL INPUTS OMITTED FOR CLARITY
OP213
10k⍀
OP213
V
OUT2
20k⍀ 20k⍀
10pF
Figure 20. Bipolar (4-Quadrant) Operation
8-Lead Standard Small Outline Package [SOIC_N]
(R-8)
S-Suffix
Dimensions shown in millimeters and (inches).
8-Lead Plastic Dual In-Line Package [PDIP]
(N-8)
Dimensions shown in inches and (millimeters).
8-Lead Thin Shrink Small Outline Package [TSSOP]
(RU-8)
Dimensions shown in millimeters.
OUTLINE DIMENSIONS