AD9708
DEFINITIONS OF SPECIFICATIONS
Linearity Error (Also Called Integral Nonlinearity or INL)
Linearity error is defined as the maximum deviation of the
actual analog output from the ideal output, determined by a
straight line drawn from zero to full scale.
Differential Nonlinearity (or DNL)
offset and gain drift, the drift is reported in ppm of full-scale
range (FSR) per degree C. For reference drift, the drift is
reported in ppm per degree C.
Power Supply Rejection
DNL is the measure of the variation in analog value, normalized
to full scale, associated with a 1 LSB change in digital input code.
Monotonicity
The maximum change in the full-scale output as the supplies
are varied from nominal to minimum and maximum specified
voltages.
Settling Time
A D/A converter is monotonic if the output either increases or
remains constant as the digital input increases.
Offset Error
The time required for the output to reach and remain within a
specified error band about its final value, measured from the
start of the output transition.
Glitch Impulse
The deviation of the output current from the ideal of zero is
called offset error. For IOUTA, 0 mA output is expected when
the inputs are all 0s. For IOUTB, 0 mA output is expected
when all inputs are set to 1s.
Gain Error
Asymmetrical switching times in a DAC give rise to undesired
output transients that are quantified by a glitch impulse. It is
specified as the net area of the glitch in pV-s.
Spurious-Free Dynamic Range
The difference between the actual and ideal output span. The
actual span is determined by the output when all inputs are set
to 1s minus the output when all inputs are set to 0s.
Output Compliance Range
The difference, in dB, between the rms amplitude of the output
signal and the peak spurious signal over the specified bandwidth.
Signal-to-Noise and Distortion (S/N+D, SINAD) Ratio
The range of allowable voltage at the output of a current-output
DAC. Operation beyond the maximum compliance limits may
cause either output stage saturation or breakdown resulting in
nonlinear performance.
Temperature Drift
S/N+D is the ratio of the rms value of the measured output
signal to the rms sum of all other spectral components below the
Nyquist frequency, including harmonics but excluding dc. The
value for S/N+D is expressed in decibels.
Total Harmonic Distortion
Temperature drift is specified as the maximum change from the
ambient (+25°C) value to the value at either T
MIN
or T
MAX
. For
+5V
0.1 F
THD is the ratio of the rms sum of the first six harmonic
components to the rms value of the measured output signal. It is
expressed as a percentage or in decibels (dB).
REFLO
+1.20V REF
0.1 F
REF IO
FS ADJ
R
SET
2k
+5V
DVDD
DCOM
CLOCK
DVDD
DCOM
RETIMED
CLOCK
OUTPUT*
LECROY 9210
PULSE GENERATOR
COMP1
50pF
AVDD
ACOM
AD9708
CURRENT
SOURCE
ARRAY
COMP2
0.1 F
IOUTA
SEGMENTED
SWITCHES
LATCHES
IOUTB
50
20pF
50
SLEEP
50
CLOCK
OUTPUT
DIGITAL
DATA
TEKTRONIX
AWG-2021
20pF
TO HP3589A
SPECTRUM/
NETWORK
ANALYZER
50 INPUT
* AWG2021 CLOCK RETIMED
SUCH THAT DIGITAL DATA
TRANSITIONS ON FALLING EDGE
OF 50% DUTY CYCLE CLOCK.
Figure 2. Basic AC Characterization Test Setup
REV. B
–5–
AD [ ANALOG DEVICES ]
