DAC8541 Datasheet, PDF (13/21 Pages) Texas Instruments – 16-BIT SINGLE CHANNEL, PARALLEL INPUT DIGITAL-TO-ANALOG CONVERTER WITH RAIL VOLTAGE OUTPUT

DAC8541
THEORY OF OPERATION
SLAS353 − DECEMBER 2001
D/A section
The architecture of the DAC8541 consists of a string DAC followed by an output buffer amplifier. Figure 29
shows a generalized block diagram of the DAC architecture.
VREFH = External Reference Voltage
DAC Register
REF+
−
Resistor
+
String
REF−
VOUTSense
VOUT
VREFL = AGND
Figure 29. Generalized DAC Architecture
The input coding to the DAC8541 is set by the BTC/USB input to the device. When this input is high, the input
code is binary 2s complement. If the input is low, the format is unipolar straight binary, in which case the ideal
output voltage is given by:
VOUT + VREFH
D
65536
Where D = the decimal equivalent of the binary code that is loaded to the DAC register, which can range from
0 to 65535 and V_REFL = AGND.
VREFH
RDIVIDE
VREFH
2
R
R
To Output Amplifier
(2x Gain)
R
R
VREFL
Figure 30. Typical Resistor String
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