FEATURES
High Slew Rate – 170 V/s
Wide Bandwidth – 28 MHz
Fast Settling Time – <200 ns to 0.01%
Low Offset Voltage – <500 V
Unity-Gain Stable
Low Voltage Operation ⴞ5 V to ⴞ15 V
Low Supply Current – <10 mA
Drives Capacitive Loads
APPLICATIONS
High-Speed Image Display Drivers
High Frequency Active Filters
Fast Instrumentation Amplifiers
High-Speed Detectors
Integrators
Photo Diode Preamps
GENERAL DESCRIPTION
The OP467 is a quad, high-speed, precision operational amplifier. It offers the performance of a high-speed op amp combined
with the advantages of a precision operational amplifier all in a
single package. The OP467 is an ideal choice for applications
where, traditionally, more than one op amp was used to achieve
this level of speed and precision.
The OP467’s internal compensation ensures stable unity-gain
operation, and it can drive large capacitive loads without oscillation. With a gain bandwidth product of 28 MHz driving a 30 pF
load, output slew rate in excess of 170 V/µs, and settling time
to 0.01% in less than 200 ns, the OP467 provides excellent
dynamic accuracy in high-speed data-acquisition systems. The
channel-to-channel separation is typically 60 dB at 10 MHz.
The dc performance of OP467 includes less than 0.5 mV of
offset, voltage noise density below 6 nV/√Hz and total supply
current under 10 mA. Common-mode rejection and power
supply rejection ratios are typically 85 dB. PSRR is maintained
to better than 40 dB with input frequencies as high as 1 MHz.
The low offset and drift plus high speed and low noise, make the
OP467 usable in applications such as high-speed detectors and
instrumentation.
The OP467 is specified for operation from ±5 V to ±15 V over
the extended industrial temperature range (–40°C to +85°C) and
is available in 14-lead plastic and ceramic DIP, plus 16-lead
SOIC and 20-terminal LCC surface mount packages.
Contact your local sales office for MIL-STD-883 data sheet
and availability.
16-Lead SOIC
(S Suffix)
–IN
Operational Amplifier
OP467
PIN CONNECTIONS
14-Lead Ceramic DIP (Y Suffix) and
14-Lead Plastic DIP (P Suffix)
OUT A
–IN A
+IN A
+IN B
–IN B
OUT B
1
2
++
3
4
V+
OP467
5
++
6
7
+IN
14
OUT D
13
–IN D
+IN D
12
11
V–
10
+IN C
9
–IN C
8
OUT C
20-Terminal LCC
(RC Suffix)
–IN A
3
+IN A
4
NC
5
V+
NC
+IN B
OP467
6
(TOP VIEW)
7
8
9
10 11
–IN B
NC = NO CONNECT
OUT A
OUT B
NC
NC
OUT D
2012
12 13
OUT C
–IN D
19
+IN D
18
NC
17
16
V–
NC
15
14
+IN C
–IN C
V+
OUT
V–
REV. D
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
VIN = 5 V Step2.5MHz
To 0.01%, VIN = 5 V Step280ns
45Degrees
NOISE PERFORMANCE
Voltage NoiseeN p-pf = 0.1 Hz to 10 Hz0.15µV p-p
Voltage Noise Densitye
Current Noise Densityi
Specifications subject to change without notice.
N
N
f = 1 kHz7nV/√Hz
f = 1 kHz8pA/√Hz
REV. D
–3–
OP467
WAFER TEST LIMITS
1
(@ VS = ⴞ15.0 V, TA = 25ⴗC unless otherwise noted.)
ParameterSymbolConditionsLimitUnit
Offset VoltageV
Input Bias CurrentI
Input Offset CurrentI
Input Voltage Range
2
OS
B
OS
Common-Mode Rejection RatioCMRRV
VCM = 0 V600nA max
VCM = 0 V100nA max
= ±12 V80dB min
CM
±0.5mV max
±12V min/max
Power Supply Rejection RatioPSRRV = ±4.5 V to ±18 V96dB min
Large Signal Voltage GainA
Output Voltage RangeV
Supply CurrentI
NOTES
1
Electrical tests and wafer probe to the limits shown. Due to variations in assembly methods and normal yield loss, yield after packaging is not guaranteed for standard
product dice. Consult factory to negotiate specifications based on dice lot qualifications through sample lot assembly and testing.
Absolute maximum ratings apply to both DICE and packaged parts, unless
otherwise noted.
2
For proper operation the positive supply must be sequenced ON before the
negative supply.
3
For supply voltages less than ± 18 V, the absolute maximum input voltage is equal
to the supply voltage.
4
θJA is specified for the worst-case conditions, i.e., θJA is specified for device in socket
for cerdip, P-DIP, and LCC packages; θJA is specified for device soldered in circuit
board for SOIC package.
OP467 Die Size 0.111 ⫻ 0.100 inch, 11,100 sq. mils Substrate is Connected to V+, Number of Transistors 165
–4–
REV. D
Typical Performance Characteristics–
OP467
80
70
60
50
40
30
20
10
OPEN-LOOP GAIN – dB
0
–10
–20
1k10k100M10M1M100k
GAIN
PHASE
FREQUENCY – Hz
TPC 1. Open-Loop Gain, Phase vs. Frequency
80
60
40
20
CLOSED-LOOP GAIN – dB
0
VS = ⴞ15V
R
= 1M⍀
L
= 30pF
C
L
VS = ⴞ15V
= 25ⴗC
T
A
0
90
180
PHASE SHIFT – Degrees
100
VS = ⴞ15V
= 25ⴗC
T
A
80
60
A
= +100
VCL
40
IMPEDANCE – ⍀
20
0
1k100k10k100
FREQUENCY – Hz
A
= +10
VCL
A
= +1
VCL
1M
TPC 4. Closed-Loop Output Impedance vs. Frequency
0.3
GAIN ERROR – dB
0.2
0.1
0.0
–0.1
–0.2
–0.3
VS = ⴞ5V
VS = ⴞ15V
–20
100k100M10M1M10k
FREQUENCY – Hz
TPC 2. Closed-Loop Gain vs. Frequency
25
20
15
TA = +125ⴗC
T
= +25ⴗC
A
10
= –55ⴗC
T
OPEN-LOOP GAIN – V/mV
A
5
0
0
ⴞ5
SUPPLY VOLTAGE – Volts
TPC 3. Open-Loop Gain vs. Supply Voltage
5.8
100k1M10M
FREQUENCY – Hz
3.4
TPC 5. Gain Linearity vs. Frequency
30
25
20
15
ⴞ15ⴞ10
ⴞ20
10
VS = ⴞ15V
MAXIMUM OUTPUT SWING – Volts
= 25ⴗC
T
5
A
= 2k⍀
R
L
0
TPC 6. Max V
10k10M1M100k1k
FREQUENCY – Hz
Swing vs. Frequency
OUT
A
VCL
= +1
A
= –1
VCL
REV. D
–5–
OP467
60
0
1600
30
10
200
20
0
50
40
140010008006001200400
LOAD CAPACITANCE – pF
OVERSHOOT – %
VS = ⴞ5V
R
L
= 2k⍀
VIN = 100mV p-p
A
VCL
= +1
A
VCL
= –1
12
10
8
6
4
MAXIMUM OUTPUT SWING – Volts
2
0
TPC 7. Max V
120
100
80
60
VS = ⴞ5V
= 25ⴗC
T
A
R
= 2k⍀
L
10k10M1M100k1k
OUT
A
= +1
VCL
A
= –1
VCL
FREQUENCY – Hz
Swing vs. Frequency
VS = ⴞ15V
T
= 25ⴗC
A
60
50
40
30
OVERSHOOT – %
20
VS = ⴞ15V
= 2k⍀
R
L
VIN = 100mV p-p
A
= +1
VCL
A
= –1
VCL
10
0
200
0
LOAD CAPACITANCE – pF
1600
140010008006001200400
TPC 10. Small Signal Overshoot vs. Load Capacitance
40
20
COMMON-MODE REJECTION – Volts
0
10k10M1M100k1k
FREQUENCY – Hz
TPC 8. Common-Mode Rejection vs. Frequency
POWER SUPPLY REJECTION – dB
120
100
80
60
40
20
0
1k1M100k10k100
FREQUENCY – Hz
VS = ⴞ15V
T
= 25ⴗC
A
TPC 9. Power-Supply Rejection vs. Frequency
TPC 11. Small Signal Overshoot vs. Load Capacitance
60
VS = ⴞ15V
50
40
30
10000pF
1000pF
500pF
200pF
20
10
GAIN – dB
0
–10
–20
–30
–40
10k100M10M1M100k
CIN = NETWORK
ANALYZER
FREQUENCY – Hz
TPC 12. Noninverting Gain vs. Capacitive Loads
–6–
REV. D
OP467
0
VS = ⴞ15V
–10
–20
–30
–40
–50
–60
–70
CHANNEL SEPARATION – dB
–80
–90
–100
1001k100M10M1M100k10k
FREQUENCY – Hz
TPC 13. Channel Separation vs. Frequency
12
ⴞ5V ⱕ VS ⱕ 15V
10
8
6
4
2
INPUT CURRENT NOISE DENSITY – pA/ Hz
0
FREQUENCY – Hz
10011k10
TPC 14. Input Current Noise Density vs. Frequency
4
VS = ⴞ15V
= ⴞ5V
V
3
IN
= 50pF
C
L
2
1
0
ERROR – mV
–1
OUT
V
–2
–3
–4
0
TIME – ns
TPC 16. Settling Time, Negative Edge
4
3
2
1
0
ERROR – mV
–1
OUT
V
–2
–3
–4
0
TIME – ns
TPC 17. Settling Time, Positive Edge
400300200100
VS = ⴞ15V
= ⴞ5V
V
IN
= 50pF
C
L
400300200100
500
500
REV. D
100
10
nV/ Hz
1.0
0.1110k1k10010
FREQUENCY – Hz
TPC 15. Voltage Noise Density vs. Frequency
–7–
20
TA = 25ⴗC
15
10
5
0
–5
–10
INPUT VOLTAGE RANGE – Volts
–15
–20
SUPPLY VOLTAGE – Volts
ⴞ15ⴞ10
ⴞ20ⴞ50
TPC 18. Input Voltage Range vs. Supply Voltage
OP467
50
VS1 = ⴞ15V
40
V
= ⴞ5V
S2
= 10k⍀
R
L
30
= 50pF
C
L
20
10
0
GAIN – dB
–10
–20
–30
–40
–50
100k100M10M1M10k
FREQUENCY – Hz
VS2 = ⴞ5V
VS1 = ⴞ15V
TPC 19. Noninverting Gain vs. Supply Voltage
14
VS = ⴞ15V
= 25ⴗC
T
A
12
10
8
6
4
OUTPUT SWING – Volts
2
POSITIVE
SWING
NEGATIVE
SWING
500
VS = ⴞ15V
T
= 25ⴗC
A
1252 ⴛ OP AMPS
400
300
UNITS
200
100
0
–50
–100
INPUT OFFSET VOLTAGE – VOS V
TPC 22. Input Offset Voltage Distribution
500
VS = ⴞ5V
T
= 25ⴗC
A
1252 ⴛ OP AMPS
400
300
UNITS
200
100
400
350300250200150100500
0
10010k1k10
LOAD RESISTANCE – ⍀
TPC 20. Output Swing vs. Load Resistance
5
VS = ⴞ5V
= 25ⴗC
T
A
4
3
2
OUTPUT SWING – Volts
1
0
POSITIVE
SWING
NEGATIVE
SWING
10010k1k10
LOAD RESISTANCE – ⍀
TPC 21. Output Swing vs. Load Resistance
0
–50
–100
INPUT OFFSET VOLTAGE – VOS V
TPC 23. Input Offset Voltage Distribution
500
VS = ⴞ15V
T
= 25ⴗC
A
1252 ⴛ OP AMPS
400
300
UNITS
200
100
0
0.5
0
TC VOS – V/ⴗC
TPC 24. TC VOS Distribution
350300250200150100500
400
5.0
4.54.03.53.02.52.01.51.0
–8–
REV. D
OP467
500
VS = ⴞ5V
TA = 25ⴗC
1252 ⴛ OP AMPS
400
300
UNITS
200
100
0
0.5
0
TC VOS – V/ⴗC
5.0
4.54.03.53.02.52.01.51.0
TPC 25. TC VOS Distribution
60
VS = ⴞ15V
55
50
45
PHASE MARGIN – Degrees
40
–75125
⍀
= 2k
R
L
–50
TEMPERATURE – ⴗC
GBW
⌽
M
7510050250–25
TPC 26. Phase Margin and Gain Bandwidth vs.
Temperature
29.0
28.5
28.0
27.5
27.0
GAIN BANDWIDTH PRODUCT – MHz
400
VS = ⴞ5V
= 2k⍀
R
L
350
300
s
250
200
150
SLEW RATE – V/
100
50
= +1
A
VCL
+SR
–SR
0
–50–75
TEMPERATURE – ⴗC
TPC 28. Slew Rate vs. Temperature
650
VS = ⴞ15V
= 2k⍀
R
600
L
= –1
A
VCL
550
500
450
400
SLEW RATE – V/s
350
300
250
–50–75
TEMPERATURE – ⴗC
–SR
+SR
TPC 29. Slew Rate vs. Temperature
125
1007550250–25
1007550250–25
125
REV. D
400
VS = ⴞ5V
= 2k⍀
R
L
350
300
250
200
150
SLEW RATE – V/s
100
50
= –1
A
VCL
–SR
+SR
0
–50–75
TEMPERATURE – ⴗC
TPC 27. Slew Rate vs. Temperature
400
350
300
250
200
150
SLEW RATE – V/s
100
50
0
125
1007550250–25
–50–75
TEMPERATURE – ⴗC
+SR
–SR
VS = ⴞ15V
= 2k⍀
R
L
= +1
A
VCL
1007550250–25
125
TPC 30. Slew Rate vs. Temperature
–9–
OP467
10
–2
–4
–6
–8
OUTPUT STEP FOR ⴞ15V SUPPLY – Volts
–10
8
6
4
2
0
RF = 5k
T
0
= 25ⴗC
A
⍀
0.01%
0.1%
0.1%0.01%
100
SETTLING TIME – ns
TPC 31. Settling Time vs. Output Step
10
TA = +125ⴗC
8
= +25ⴗC
T
A
T
= –55ⴗC
A
6
INPUT BIAS CURRENT – nA
200
160
120
80
40
0
–75
VS = ⴞ15V
–50
TEMPERATURE –
1007550250–25
ⴗ
C
125
5
4
3
2
1
0
–5
–4
–3
OUTPUT STEP FOR ⴞ5V SUPPLY – Volts
–2
–1
300200
400
TPC 33. Input Bias Current vs. Temperature
25
VS = ⴞ15V
20
15
4
SUPPLY CURRENT – mA
2
0
0
ⴞ5
SUPPLY VOLTAGE – Volts
ⴞ15ⴞ10
TPC 32. Supply Current vs. Supply Voltage
ⴞ20
10
INPUT OFFSET CURRENT – nA
5
0
–50
–75
TEMPERATURE –
C
1007550250–25
TPC 34. Input Offset Current vs. Temperature
125
–10–
REV. D
OP467
APPLICATIONS INFORMATION
OUTPUT SHORT-CIRCUIT PERFORMANCE
To achieve a wide bandwidth and high slew rate, the OP467
output is not short circuit protected. Shorting the output to
ground or to the supplies may destroy the device.
For safe operation, the output load current should be limited
so that the junction temperature does not exceed the absolute
maximum junction temperature.
To calculate the maximum internal power dissipation, the following formula can be used:
TT
–
max
J
P
=
D
A
θ
J
A
where TJ and TA are junction and ambient temperatures respectively, P
is device internal power dissipation, and θJA is pack-
D
aged device thermal resistance given in the data sheet.
UNUSED AMPLIFIERS
It is recommended that any unused amplifiers in a quad package
be connected as a unity gain follower with a 1 kΩ feedback resistor
with noninverting input tied to the ground plain.
PRINTED CIRCUIT BOARD LAYOUT
CONSIDERATIONS
Satisfactory performance of a high-speed op amp largely depends
on a good PC layout. To achieve the best dynamic performance,
following high frequency layout technique is recommended.
GROUNDING
A good ground plain is essential to achieve the optimum performance in high-speed applications. It can significantly reduce the
undesirable effects of ground loops and IR drops by providing a
low impedance reference point. Best results are obtained with a
multilayer board design with one layer assigned to ground plain.
To maintain a continuous and low impedance ground, avoid
running any traces on this layer.
POWER SUPPLY CONSIDERATIONS
For proper operation the positive supply must be sequenced ON
before the negative supply. All users should take steps to ensure
this. In high frequency circuits, device lead length introduces an
inductance in series with the circuit. This inductance, combined
with stray capacitance, forms a high frequency resonance circuit.
Poles generated by these circuits will cause gain peaking and
additional phase shift, reducing the op amp’s phase margin and
leading to an unstable operation.
A practical solution to this problem is to reduce the resonance
frequency low enough to take advantage of the amplifier’s power
supply rejection.
This is easily done by placing capacitors across the supply line
and the ground plain as close as possible to the device pin. Since
capacitors also have internal parasitic components, such as stray
inductance, selecting the right capacitor is important. To be
effective, they should have low impedance over the frequency
range of interest. Tantalum capacitors are an excellent choice
for their high capacitance/size ratio, but their ESR (Effective
Series Resistance) increases with frequency making them less
effective. On the other hand, ceramic chip capacitors have excellent ESR and ESL (Effective Series Inductance) performance at
higher frequencies, and because of their small size, they can be
placed very close to the device pin, further reducing the stray
inductance. Best results are achieved by using a combination of
these two capacitors. A 5 µF–10 µF tantalum parallel with a
0.1 µF ceramic chip caps are recommended. If additional isolation from high frequency resonances of the power supply is
needed, a ferrite bead should be placed in series with the supply
lines between the bypass caps and the power supply. A word of
caution, addition of the ferrite bead will introduce a new pole
and zero to frequency response of the circuit and could cause
unstable operation if it is not selected properly.
+V
S
+
10F TANTALUM
0.1F CERAMIC CHIP
0.1F CERAMIC CHIP
10F TANTALUM
–
–V
S
Figure 2. Recommended Power Supply Bypass
SIGNAL CONSIDERATIONS
Input and output traces need special attention to assure a minimum stray capacitance. Input nodes are very sensitive to capacitive reactance, particularly when connected to a high impedance
circuit. Stray capacitance can inject undesirable signals from a
noisy line into a high impedance input. Protect high impedance
input traces by providing guard traces around them. This will
also improve the channel separation significantly.
Additionally, any stray capacitance in parallel with the op amp’s
input capacitance generates a pole in the frequency response of
the circuit. The additional phase shift caused by this pole will
reduce the circuit’s gain margin. If this pole is within the gain
range of the op amp, it will cause unstable performance. To reduce
these undesirable effects, use the lowest impedance where possible. Lowering the impedance at this node places the poles at a
higher frequency, far above the gain range of the amplifier. Stray
capacitance on the PC board can be reduced by making the
traces narrow and as short as possible. Further reduction can be
realized by choosing smaller pad size, increasing the spacing
between the traces, and using PC board material with a low
dielectric constant insulator (Dielectric Constant of some common insulators: air = 1, Teflon
®
= 2.2, and FR4 = 4.7; with air
being an ideal insulator).
Removing segments of the ground plain directly under the input
and output pads is recommended.
Outputs of high-speed amplifiers are very sensitive to capacitive
loads. A capacitive load will introduce a pair of pole and zero to
the circuit’s frequency response, reducing the phase margin,
leading to unstable operation or oscillation.
Teflon is a registered trademark of E.I. du Pont Co.
REV. D
–11–
OP467
Generally, it is a good design practice to isolate the amplifier’s
output from any capacitive load by placing a resistor between
the amplifier’s output and the rest of the circuits. A series resistor of 10 Ω to 100 Ω is normally sufficient to isolate the output
from a capacitive load.
The OP467 is internally compensated to provide stable operation, and is capable of driving large capacitive loads without
oscillation.
Sockets are not recommended since they increase the lead
inductance/capacitance and reduce the power dissipation of the
package by increasing the leads’ thermal resistance. If sockets
must be used, use Teflon or pin sockets with the shortest
possible leads.
PHASE REVERSAL
The OP467 is immune to phase reversal; its inputs can exceed
the supply rails by a diode drop without any phase reversal.
15.8V
⌬
V1
100
90
OUTPUT
10
INPUT
0%
10V10V
200s
DLY 4.806s
100
90
10
0%
5V
5V
20ns
Figure 5. Saturation Recovery Time, Negative Rail
HIGH-SPEED INSTRUMENTATION AMPLIFIER
The OP467 performance lends itself to a variety of high-speed
applications, including high-speed precision instrumentation
amplifiers. Figure 6 represents a circuit commonly used for data
acquisition, CCD imaging, and other high-speed applications.
Circuit gain is set by R
to 2; for unity gain, remove R
. A 2 kΩ resistor will set the circuit gain
G
. For any other gain settings use
G
the following formula:
G = 2/R
R
is used for adjusting the dc common-mode rejection, and C
C
Resistor Value is in kΩ
G
C
is used for ac common-mode rejection adjustments.
–V
IN
C
C
Figure 3. No Phase Reversal (AV = +1)
SATURATION RECOVERY TIME
The OP467 has a fast and symmetrical recovery time from either
rail. This feature is very useful in applications such as high-speed
instrumentation and measurement circuits, where the amplifier
is frequently exposed to large signals that overload the amplifier.
DLY 9.842s
100
90
10
0%
5V
5V
20ns
Figure 4. Saturation Recovery Time, Positive Rail
1.9k⍀
R
C
200
10T
2k⍀
OUTPUT
⍀
1k⍀
10k⍀
R
G
1k⍀
10k⍀
+V
IN
2k⍀
2k⍀
5pF
Figure 6. A High-Speed Instrumentation Amplifier
0.01% 10V STEP
VS = ⴞ15V
NEG SLOPE
2.5mV
–2.5mV
Figure 7. Instrumentation Amplifier Settling Time to
0.01% for a 10 V Step Input (Negative Slope)
–12–
REV. D
OP467
2k⍀
R1
3k⍀
V
IN
R3
2k⍀
R2
2k⍀
R4
2k⍀
R5
2k⍀
C2
50pF
C1
50pF
R6
1k⍀
V
OUT
+
–
+
–
+
–
+
–
1/4
OP467
1/4
OP467
1/4
OP467
1/4
OP467
0.01% 10V STEP
= ⴞ15V
V
S
POS SLOPE
2.5mV
–2.5mV
Figure 8. Instrumentation Amplifier Settling Time to
0.01% for a 10 V Step Input (Positive Slope)
+V
S
+
–V
+
AD9617
–
–
S
549⍀
1k⍀
ERROR
TO
SCOPE
INPUT
TO
IN-AMP
OUTPUT
TO
2k⍀
2k⍀
61.9⍀
2 MHz BIQUAD BANDPASS FILTER
The circuit in Figure 10 is commonly used in medical imaging
ultrasound receivers. The 30 MHz bandwidth is sufficient to
accurately produce the 2 MHz center frequency, as the measured
response shows in Figure 11. When the op amp’s bandwidth is
too close to the filter’s center frequency, the amplifier’s internal
phase shift causes excess phase shift at 2 MHz, which alters the
filter’s response. In fact, if the chosen op amp has a bandwidth
close to 2 MHz, the combined phase shift of the three op amps
will cause the loop to oscillate.
Careful consideration must be given to the layout of this circuit
as with any other high-speed circuit.
If the phase shift introduced by the layout is large enough, it
could alter the circuit performance, or worse, it will oscillate.
REV. D
Figure 9. Settling Time Measurement Circuit
Figure 10. 2 MHz Biquad Filter
0
–10
–20
GAIN – dB
–30
–40
100k100M10M1M10k
FREQUENCY – Hz
Figure 11. Biquad Filter Response
–13–
OP467
+5V
V
1
2
3
4
5
6
7
8
9
10
11
12
13
14
DD
DAC8408
V
A
REF
R
A
FB
I
1A
OUT
2A/
I
OUT
2B
I
OUT
1B
I
OUT
B
R
FB
B
V
REF
DB0 (LSB)
DB1
DB2
DB3
DB4
DB5
(MSB) DB7
+10V
C1
V
A
OUT
0.1F
V
B
OUT
0.1F
1
7
OP467
+15V
4
OP467
11
–15V
–
3
+
6
–
5
+
2
10pF
C2
10pF
+10V
Figure 12. Quad DAC Unipolar Operation
FAST I-TO-V CONVERTER
The fast slew rate and fast settling time of the OP467 are well
suited to the fast buffers and I-to-V converters used in variety of
applications. The circuit in Figure 12 is a unipolar quad D/A
converter consisting of only two ICs. The current output of the
DAC8408 is converted to a voltage by the OP467 configured as
an I-to-V converter. This circuit is capable of settling to 0.1%
within 200 ns. Figures 13 and 14 show the full-scale settling
time of the outputs. To obtain reliable circuit performance, keep
the traces from the DAC’s I