DAC088S085 Datasheet, PDF (8/24 Pages) National Semiconductor (TI) – 8-Bit Micro Power OCTAL Digital-to-Analog Converter with Rail-to-Rail Outputs

Specification Definitions
DIFFERENTIAL NON-LINEARITY (DNL) is the measure of
the maximum deviation from the ideal step size of 1 LSB,
which is V_REF / 256 = V_A / 256.
DAC-to-DAC CROSSTALK is the glitch impulse transferred
to a DAC output in response to a full-scale change in the out-
put of another DAC.
DIGITAL CROSSTALK is the glitch impulse transferred to a
DAC output at mid-scale in response to a full-scale change in
the input register of another DAC.
DIGITAL FEEDTHROUGH is a measure of the energy inject-
ed into the analog output of the DAC from the digital inputs
when the DAC outputs are not updated. It is measured with a
full-scale code change on the data bus.
FULL-SCALE ERROR is the difference between the actual
output voltage with a full scale code (FFh) loaded into the DAC
and the value of V_A x 255 / 256.
GAIN ERROR is the deviation from the ideal slope of the
transfer function. It can be calculated from Zero and Full-
Scale Errors as GE = FSE - ZE, where GE is Gain error, FSE
is Full-Scale Error and ZE is Zero Error.
GLITCH IMPULSE is the energy injected into the analog out-
put when the input code to the DAC register changes. It is
specified as the area of the glitch in nanovolt-seconds.
INTEGRAL NON-LINEARITY (INL) is a measure of the de-
viation of each individual code from a straight line through the
input to output transfer function. The deviation of any given
code from this straight line is measured from the center of that
code value. The end point method is used. INL for this product
is specified over a limited range, per the Electrical Tables.
LEAST SIGNIFICANT BIT (LSB) is the bit that has the small-
est value or weight of all bits in a word. This value is
LSB = V_REF / 2ⁿ
Transfer Characteristic
where V_REF is the supply voltage for this product, and "n" is
the DAC resolution in bits, which is 8 for the DAC088S085.
MAXIMUM LOAD CAPACITANCE is the maximum capaci-
tance that can be driven by the DAC with output stability
maintained.
MONOTONICITY is the condition of being monotonic, where
the DAC has an output that never decreases when the input
code increases.
MOST SIGNIFICANT BIT (MSB) is the bit that has the largest
value or weight of all bits in a word. Its value is 1/2 of V_A.
MULTIPLYING BANDWIDTH is the frequency at which the
output amplitude falls 3dB below the input sine wave on
V_REF1,2 with the DAC code at full-scale.
NOISE SPECTRAL DENSITY is the internally generated ran-
dom noise. It is measured by loading the DAC to mid-scale
and measuring the noise at the output.
POWER EFFICIENCY is the ratio of the output current to the
total supply current. The output current comes from the power
supply. The difference between the supply and output cur-
rents is the power consumed by the device without a load.
SETTLING TIME is the time for the output to settle to within
1/2 LSB of the final value after the input code is updated.
TOTAL HARMONIC DISTORTION PLUS NOISE (THD+N)
is the ratio of the harmonics plus the noise present at the out-
put of the DACs to the rms level of an ideal sine wave applied
to V_REF1,2 with the DAC code at mid-scale.
WAKE-UP TIME is the time for the output to exit power-down
mode. This is the time from the rising edge of SYNC to when
the output voltage deviates from the power-down voltage of
0V.
ZERO CODE ERROR is the output error, or voltage, present
at the DAC output after a code of 00h has been entered.
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FIGURE 2. Input / Output Transfer Characteristic
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