AD5555CRU Analog Devices Inc, AD5555CRU Datasheet - Page 15

• Manufacturer Part Number: AD5555CRU
• Description: IC DAC 14BIT DUAL SRL IN 16TSSOP
• Manufacturer: Analog Devices Inc

Specifications of AD5555CRU

• Rohs Status: RoHS non-compliant
• Settling Time: 500ns
• Number Of Bits: 14
• Data Interface: Serial
• Number Of Converters: 2
• Voltage Supply Source: Single Supply
• Power Dissipation (max): 55µW
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-TSSOP

REFERENCE SELECTION
When selecting a reference for use with the AD55xx series
of current output DACs, pay attention to the output voltage,
temperature coefficient specification of the reference. Choosing
a precision reference with a low output temperature coefficient
minimizes error sources. Table 10 lists some of the references
available from Analog Devices, Inc., that are suitable for use
with this range of current output DACs.
AMPLIFIER SELECTION
The primary requirement for the current-steering mode is an
amplifier with low input bias currents and low input offset voltage.
Because of the code-dependent output resistance of the DAC,
the input offset voltage of an op amp is multiplied by the variable
gain of the circuit. A change in this noise gain between two
adjacent digital fractions produces a step change in the output
voltage due to the amplifier’s input offset voltage. This output
voltage change is superimposed upon the desired change in
output between the two codes and gives rise to a differential
linearity error, which, if large enough, can cause the DAC to be
nonmonotonic.
Table 10. Suitable Analog Devices Precision References
Part No.
ADR01
ADR01
ADR02
ADR02
ADR03
ADR03
ADR06
ADR06
ADR420
ADR421
ADR423
ADR425
ADR431
ADR435
ADR391
ADR395
Output Voltage (V)
10
10
5.0
5.0
2.5
2.5
3.0
3.0
2.048
2.50
3.00
5.00
2.500
5.000
2.5
5.0
Initial Tolerance (%)
0.05
0.05
0.06
0.06
0.1
0.1
0.1
0.1
0.05
0.04
0.04
0.04
0.04
0.04
0.16
0.10
Maximum Temperature
Drift (ppm/°C)
3
9
3
9
3
9
3
9
3
3
3
3
3
3
9
9
Rev. C | Page 15 of 20
The input bias current of an op amp also generates an offset at
the voltage output because of the bias current flowing in the
feedback resistor, R
Common-mode rejection of the op amp is important in voltage-
switching circuits because it produces a code-dependent error
at the voltage output of the circuit.
Provided that the DAC switches are driven from true wideband
low impedance sources (V
Consequently, the slew rate and settling time of a voltage-switching
DAC circuit is determined largely by the output op amp. To obtain
minimum settling time in this configuration, minimize capacitance
at the V
the DAC. This is done by using low input capacitance buffer
amplifiers and careful board design.
Analog Devices offers a wide range of amplifiers for both precision
dc and ac applications, as listed in Table 11 and Table 12.
REF
node (the voltage output node in this application) of
I
1
1
1
1
1
1
1
1
0.5
0.5
0.5
0.5
0.8
0.8
0.12
0.12
SS
(mA)
FB
.
Output Noise (μV p-p)
20
20
10
10
6
6
10
10
1.75
1.75
2
3.4
3.5
8
5
8
IN
and AGND), they settle quickly.
AD5545/AD5555
Package(s)
SOIC-8
TSOT-5, SC70-5
SOIC-8
TSOT-5, SC70-5
SOIC-8
TSOT-5, SC70-5
SOIC-8
TSOT-5, SC70-5
SOIC-8, MSOP-8
SOIC-8, MSOP-8
SOIC-8, MSOP-8
SOIC-8, MSOP-8
SOIC-8, MSOP-8
SOIC-8, MSOP-8
TSOT-5
TSOT-5