DAC8871_08 BURR-BROWN [Burr-Brown Corporation], DAC8871_08 Datasheet - Page 14

• Manufacturer Part Number: DAC8871_08
• Manufacturer: BURR-BROWN [Burr-Brown Corporation]

DAC8871
SBAS396 – JUNE 2007
14
GENERAL DESCRIPTION
The DAC8871 is a 16-bit, single-channel, serial-input, voltage-output DAC. It operates from a dual power supply
ranging from 13.5V to 19.8V, and typically consumes 10 A. The output range is from V
written to this device in a 16-bit word format, via an SPI serial interface. To ensure a known power-up state, the
DAC8871 is designed with a power-on reset function. After power on, the state of the RSTSEL pin sets the
value of the input register and DAC latch, which sets the output state of the V
Reset and Hardware Reset
Kelvin sense connections for the reference and analog ground are also included.
DIGITAL-TO-ANALOG SECTIONS
The DAC architecture consists of two matched DAC sections and is segmented. A simplified circuit diagram is
shown in
of these switches connects one of 15 matched resistors to either AGND or V
data word drive switches S0 to S11 of a 12-bit voltage mode R-2R ladder network.
OUTPUT RANGE
The output of the DAC is:
Where Code is the decimal data word loaded to the DAC latch.
For example, if V
= FFFFh).
The range of V
DAC8871 can be unipolar (from 0V to +18V) or bipolar by setting the proper V
V
OUT
+
( V
Figure
REFH
65536 ) V
* V
REFL
38. The four MSBs of the 16-bit data word are decoded to drive 15 switches, E1 to E15. Each
REFH
REFL
is from –18V to (V
is +10V, and V
)
REFL
V
V
V
V
REFH
REFH
REFL
REFL
Code
section for more details.
-F
-S
-F
-S
2R
REFL
REFH
12-Bit R-2R Ladder
Figure 38. DAC Architecture
THEORY OF OPERATION
is –10V, the range of V
S0
2R
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– 1.25V), and the range of V
R
S1
2R
S11
2R
R
Four MSBs Decoded into
OUT
15 Equal Segments
E1
2R
is from –10V (code = 0000h) to +10V (code
REFH
E2
2R
is 0V to +18V. The output from the
REFL
REF
OUT
. The remaining 12 bits of the
E15
and V
2R
V
pin. Refer to the
OUT
REFH
REFL
values.
to V
REFH
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. Data are
Power-On
(1)