AD5628 Analog Devices, AD5628 Datasheet - Page 19

• Manufacturer Part Number: AD5628
• Manufacturer: Analog Devices

Specifications of AD5628

• Resolution (bits): 12bit
• Dac Update Rate: 95kSPS
• Dac Settling Time: 6µs
• Max Pos Supply (v): +5.5V
• Single-supply: Yes
• Dac Type: Voltage Out
• Dac Input Format: Ser,SPI

Data Sheet
TERMINOLOGY
Relative Accuracy
For the DAC, relative accuracy, or integral nonlinearity (INL), is
a measure of the maximum deviation in LSBs from a straight line
passing through the endpoints of the DAC transfer function.
Figure 7 to Figure 9, Figure 13 to Figure 15, and Figure 19 to
Figure 21 show plots of typical INL vs. code.
Differential Nonlinearity
Differential nonlinearity (DNL) is the difference between the
measured change and the ideal 1 LSB change between any two
adjacent codes. A specified differential nonlinearity of ±1 LSB
maximum ensures monotonicity. This DAC is guaranteed mono-
tonic by design. Figure 10 to Figure 12, Figure 16 to Figure 18,
and Figure 22 to Figure 24 show plots of typical DNL vs. code.
Offset Error
Offset error is a measure of the difference between the actual
V
region of the transfer function. Offset error is measured on the
AD5668 with Code 512 loaded into the DAC register. It can be
negative or positive and is expressed in millivolts.
Zero-Code Error
Zero-code error is a measure of the output error when zero
code (0x0000) is loaded into the DAC register. Ideally, the
output should be 0 V. The zero-code error is always positive in
the AD5628/AD5648/AD5668, because the output of the DAC
cannot go below 0 V. It is due to a combination of the offset
errors in the DAC and output amplifier. Zero-code error is
expressed in millivolts. Figure 28 shows a plot of typical zero-
code error vs. temperature.
Gain Error
Gain error is a measure of the span error of the DAC. It is the
deviation in slope of the DAC transfer characteristic from the
ideal, expressed as a percentage of the full-scale range.
Zero-Code Error Drift
Zero-code error drift is a measure of the change in zero-code
error with a change in temperature. It is expressed in μV/°C.
Gain Error Drift
Gain error drift is a measure of the change in gain error with
changes in temperature. It is expressed in (ppm of full-scale
range)/°C.
Full-Scale Error
Full-scale error is a measure of the output error when full-scale
code (0xFFFF) is loaded into the DAC register. Ideally, the
output should be V
percentage of the full-scale range. Figure 25 shows a plot of
typical full-scale error vs. temperature.
OUT
and the ideal V
DD
OUT
– 1 LSB. Full-scale error is expressed as a
, expressed in millivolts in the linear
Rev. F | Page 19 of 32
Digital-to-Analog Glitch Impulse
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 nV-s and
is measured when the digital input code is changed by 1 LSB at
the major carry transition (0x7FFF to 0x8000). See Figure 42.
DC Power Supply Rejection Ratio (PSRR)
PSRR indicates how the output of the DAC is affected by changes
in the supply voltage. PSRR is the ratio of the change in V
a change in V
in decibels. V
DC Crosstalk
DC crosstalk is the dc change in the output level of one DAC in
response to a change in the output of another DAC. It is measured
with a full-scale output change on one DAC (or soft power-down
and power-up) while monitoring another DAC kept at midscale.
It is expressed in microvolts.
DC crosstalk due to load current change is a measure of the
impact that a change in load current on one DAC has to another
DAC kept at midscale. It is expressed in microvolts per milliamp.
Reference Feedthrough
Reference feedthrough is the ratio of the amplitude of the signal
at the DAC output to the reference input when the DAC output
is not being updated (that is, LDAC is high). It is expressed in
decibels.
Digital Feedthrough
Digital feedthrough is a measure of the impulse injected into
the analog output of a DAC from the digital input pins of the
device, but is measured when the DAC is not being written to
( SYNC held high). It is specified in nV-s and measured with a
full-scale change on the digital input pins, that is, from all 0s to
all 1s or vice versa.
Digital Crosstalk
Digital crosstalk is the glitch impulse transferred to the output
of one DAC at midscale in response to a full-scale code change
(all 0s to all 1s or vice versa) in the input register of another DAC.
It is measured in standalone mode and is expressed in nV-s.
Analog Crosstalk
Analog crosstalk is the glitch impulse transferred to the output
of one DAC due to a change in the output of another DAC. It is
measured by loading one of the input registers with a full-scale
code change (all 0s to all 1s or vice versa) while keeping LDAC
high, and then pulsing LDAC low and monitoring the output of
the DAC whose digital code has not changed. The area of the
glitch is expressed in nV-s.
DD
REF
for full-scale output of the DAC. It is measured
is held at 2 V, and V
AD5628/AD5648/AD5668
DD
is varied ±10%.
OUT
to