7.4 Device Functional Modes
7.4.1 Voltage-Output Mode
The voltage-output mode for each DAC channel can be entered by selecting the power-up option in the VOUT-
PDN-X fields in the COMMON-CONFIG register and simultaneously powering down the current output option
for the respective channels using the IOUT-PDN-X bits in the same register. Short the OUTx and FBx pins of
respective channels externally for closed-loop amplifier output. An open FBx pin saturates the amplifier output.
To achieve the desired voltage output, select the correct reference option, select the amplifier gain for the
required output range, and program the DAC code in the DAC-X-DATA register of the respective channels.
7.4.1.1 Voltage Reference and DAC Transfer Function
shows that there are three voltage reference options possible with the DACx3202: internal reference,
external reference, and the power supply as reference. The DAC transfer function in the voltage-output and
comparator modes changes based on the voltage reference selection.
Internal
Reference
VREF
VDD
MUX
Digital
IO
VOUT-GAIN-X
DIS-MODE-IN
EN-INT-REF
DAC Ladder
+
–
OUTx
FBx
R
1
R
2
CMP-X-HIZ-IN-DIS or
VOUT-PDN-X (Hi-Z)
VOUT-PDN-X
Internal
Bandgap
IOUT-PDN-X
IOUT-RANGE-X
10k
/100k
AGND
IOUT-PDN-X
VOUT-PDN-X
Figure 7-2. Voltage Reference Selection and Power-Down Logic
7.4.1.1.1 Internal Reference
The DACx3202 contain an internal reference that is disabled by default. To enable the internal reference, write
1 to bit EN-INT-REF in the COMMON-CONFIG register. The internal reference generates a fixed 1.21-V voltage
(typical). Use the VOUT-GAIN-X bit in the DAC-X-VOUT-CMP-CONFIG register to achieve gains of 1.5x, 2x, 3x,
or 4x for the DAC output voltage (V
OUT
).
shows DAC transfer function using the internal reference.
V
OUT
=
DAC_DATA
2N
× V
REF
× GAIN
(1)
where:
• N is the resolution in bits, 10 (DAC53202), or 12 (DAC63202).
• DAC_DATA is the decimal equivalent of the binary code that is loaded to the DAC-X-DATA bit in the
DAC-X-DATA register. DAC_DATA ranges from 0 to 2
N
– 1.
• V
REF
is the internal reference voltage = 1.21 V (typical).
• GAIN = 1.5x, 2x, 3x, or 4x, based on VOUT-X-GAIN bits.
SLASF47 – MAY 2022
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27
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