DAC8565 Datasheet, PDF (40/46 Pages) Texas Instruments – 16-Bit, Quad Channel, Ultra-Low Glitch, Voltage Output DIGITAL-TO-ANALOG CONVERTER with 2.5V, 2ppm/°C Internal Reference

DAC8565
SBAS411A – JUNE 2007 – REVISED NOVEMBER 2007
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Zero-Code Error Drift
Zero-code error drift is defined as the change in
zero-code error with a change in temperature.
Zero-code error drift is expressed in µV/°C.
Gain Temperature Coefficient
The gain temperature coefficient is defined as the
change in gain error with changes in temperature.
The gain temperature coefficient is expressed in ppm
of FSR/°C.
Power-Supply Rejection Ratio (PSRR)
Power-supply rejection ratio (PSRR) is defined as the
ratio of change in output voltage to a change in
supply voltage for a full-scale output of the DAC. The
PSRR of a device indicates how the output of the
DAC is affected by changes in the supply voltage.
PSRR is measured in decibels (dB).
Monotonicity
Monotonicity is defined as a slope whose sign does
not change. If a DAC is monotonic, the output
changes in the same direction or remains at least
constant for each step increase (or decrease) in the
input code.
DYNAMIC PERFORMANCE
Dynamic performance parameters are specifications such as settling time or slew rate. Those are important in
applications where the signal is rapidly changing and/or high frequency signals are present.
Slew Rate
The output slew-rate (SR) of an amplifier or other
electronic circuit is defined as the maximum rate of
change of the output voltage for all possible input
signals.
SR = max
DV_OUT(t)
Dt
Where ΔV_OUT(t) is the output produced by the
amplifier as a function of time t.
Output Voltage Settling Time
Settling time is the total time (including slew time) for
the DAC output to settle within an error band around
its final value after a change in input. Settling times
are specified to within ±0.003% (or whatever value is
specified) of full-scale range (FSR).
Code Change/Digital-to-Analog Glitch Energy
Digital-to-analog glitch impulse is the impulse injected
into the analog output when the input code in the
DAC register changes state. It is normally specified
as the area of the glitch in nanovolts-second (nV-s),
and is measured when the digital input code is
changed by 1LSB at the major carry transition
(0x7FFF to 0x8000).
Digital Feedthrough
Digital feedthrough is defined as impulse seen at the
output of the DAC from the digital inputs of the DAC.
It is measured when the DAC output is not updated. It
is specified in nV-s, and measured with a full-scale
code change on the data bus; that is, from all '0's to
all '1's and vice versa.
Channel-to-Channel DC Crosstalk
Channel-to-channel dc crosstalk is defined as the dc
change in the output level of one DAC channel in
response to a change in the output of another DAC
channel. It is measured with a full-scale output
change on one DAC channel while monitoring
another DAC channel remains at mid-scale. It is
expressed in LSB.
Channel-to-Channel AC Crosstalk
AC crosstalk in multi-channel DAC is defined as
amount of ac interference experienced on the output
of a channel at a frequency (f) (and its harmonics),
when the output of an adjacent channel changes its
value at the rate of frequency (f). It is measured with
one channel output oscillating with sine wave of 1KHz
frequency while monitoring amplitude of 1KHz
harmonics on an adjacent DAC channel output (kept
at zero scale). It is expressed in dB.
Signal-to-Noise Ratio (SNR)
Signal-to-noise ratio (SNR) is defined as the ratio of
root mean-squared (RMS) value of the output signal
divided by the RMS values of the sum of all other
spectral components below one-half the output
frequency, not including harmonics or dc. SNR is
measured in dB.
Total Harmonic Distortion (THD)
Total harmonic distortion + noise is defined as the
ratio of the RMS values of the harmonics and noise
to the value of the fundamental frequency. It is
expressed in a percentage of the fundamental
frequency amplitude at sampling rate f_S.
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