7.4.5.2 Function Generation
The DACx3202 implement a continuous function or waveform generation feature. These devices can generate a
triangular wave, sawtooth wave, and sine wave independently for every channel.
7.4.5.2.1 Triangular Waveform Generation
The triangular waveform uses the DAC-X-MARGIN-LOW and DAC-X-MARGIN-HIGH registers for minimum
and maximum levels, respectively.
shows that the frequency of the waveform depends on the min
and max levels, CODE-STEP and SLEW-RATE settings. An external RC load with a time-constant larger than
the slew-rate settings can be dominant over the internal frequency calculation. The CODE-STEP-X and SLEW-
RATE-X settings are available in the DAC-X-FUNC-CONFIG register. Writing 0b000 to the FUNC-CONFIG-X bit
field in the DAC-X-FUNC-CONFIG register selects triangular waveform.
f
TRIANGLE_WAVE
=
1
2 × SLEW_RATE × MARGIN_HIGH − MARG 1
CODE_STEP
(6)
where:
• SLEW_RATE is the SLEW-RATE-X setting specified in
• CODE_STEP is the CODE-STEP-X setting specified in
.
• MARGIN_HIGH is the DAC-X-MAGIN-HIGH specified in
• MARGIN_LOW is the DAC-X-MAGIN-LOW specified in
7.4.5.2.2 Sawtooth Waveform Generation
The sawtooth and the inverse sawtooth waveforms use the DAC-X-MARGIN-LOW and DAC-X-MARGIN-HIGH
registers for minimum and maximum levels, respectively.
shows that the frequency of the waveform
depends on the min and max levels, CODE-STEP and SLEW-RATE settings. An external RC load with a
time constant larger than the slew-rate settings can be dominant over the internal frequency calculation. The
CODE-STEP-X and SLEW-RATE-X settings are available in the DAC-X-FUNC-CONFIG register. Write 0b001
to the FUNC-CONFIG-X bit field in the DAC-X-FUNC-CONFIG register to select sawtooth waveform, and write
0b010 to select inverse sawtooth waveform.
f
SAWTOOTH_WAVE
=
1
SLEW_RATE × MARGIN_HIGH − MARG 1
CODE_STEP
(7)
where:
• SLEW_RATE is the SLEW-RATE-X setting specified in
• CODE_STEP is the CODE-STEP-X setting specified in
.
• MARGIN_HIGH is the DAC-X-MAGIN-HIGH specified in
• MARGIN_LOW is the DAC-X-MAGIN-LOW specified in
SLASF47 – MAY 2022
Copyright © 2022 Texas Instruments Incorporated
39
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