AC PERFORMANCE
1 ms Settling to 0.01% for 10 V Step
20 V/ms Slew Rate
0.0003% Total Harmonic Distortion (THD)
4 MHz Unity Gain Bandwidth
DC PERFORMANCE
0.5 mV max Offset Voltage (AD713K)
20 mV/°C max Drift (AD713K)
200 V/mV min Open Loop Gain (AD713K)
2 mV p-p typ Noise, 0.1 Hz to 10 Hz
True 14-Bit Accuracy
Single Version: AD711, Dual Version: AD712
Available in 16-Pin SOIC, 14-Pin Plastic DIP and
Hermetic Cerdip Packages
Standard Military Drawing Available
APPLICATIONS
Active Filters
Quad Output Buffers for 12- and 14-Bit DACs
Input Buffers for Precision ADCs
Photo Diode Preamplifier Application
High Speed, BiFET Op Amp
AD713
CONNECTION DIAGRAMS
Plastic (N) and
Cerdip (Q) PackagesSOIC (R) Package
1
OUTPUT
OUTPUT
+V
OUTPUT
–IN
+IN
+IN
–IN
1
1
2
3
AD713
4
S
5
6
7
(TOP VIEW)
2
14
OUTPUT
4
–IN
13
12
+IN
–V
11
+IN
10
–IN
9
3
8
OUTPUT
S
+V
OUTPUT
–IN
+IN
S
+IN
–IN
NC
1
2
3
AD713
4
(TOP VIEW)
5
6
2
7
8
NC = NO CONNECT
The AD713 is offered in a 16-pin SOIC, 14-pin plastic DIP and
hermetic cerdip package.
16
OUTPUT
4
15
–IN
14
+IN
13
–V
S
12
+IN
–IN
11
3
10
OUTPUT
9
NC
PRODUCT DESCRIPTION
The AD713 is a quad operational amplifier, consisting of four
AD711 BiFET op amps. These precision monolithic op amps
offer excellent dc characteristics plus rapid settling times, high
slew rates, and ample bandwidths. In addition, the AD713
provides the close matching ac and dc characteristics inherent
to amplifiers sharing the same monolithic die.
The single-pole response of the AD713 provides fast settling:
l µs to 0.01%. This feature, combined with its high dc precision,
makes the AD713 suitable for use as a buffer amplifier for 12or 14-bit DACs and ADCs. It is also an excellent choice for use
in active filters in 12-, 14- and 16-bit data acquisition systems.
Furthermore, the AD713’s low total harmonic distortion (THD)
level of 0.0003% and very close matching ac characteristics
make it an ideal amplifier for many demanding audio applications.
The AD713 is internally compensated for stable operation at
unity gain and is available in seven performance grades. The
AD713J and AD713K are rated over the commercial temperature
range of 0°C to 70°C. The AD713A and AD713B are rated
over the industrial temperature of –40°C to +85°C. The
AD713S and AD713T are rated over the military temperature
range of –55°C to +125°C and are available processed to
standard microcircuit drawings.
REV. C
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 that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices.
PRODUCT HIGHLIGHTS
1. The AD713 is a high speed BiFET op amp that offers excellent
performance at competitive prices. It upgrades the performance of circuits using op amps such as the TL074, TL084,
LT1058, LF347 and OPA404.
2. Slew rate is 100% tested for a guaranteed minimum of
16 V/µs (J, A and S Grades).
3. The combination of Analog Devices’ advanced processing
technology, laser wafer drift trimming and well-matched
ion-implanted JFETs provides outstanding dc precision.
Input offset voltage, input bias current and input offset current are specified in the warmed-up condition and are 100%
tested.
4. Very close matching of ac characteristics between the four
amplifiers makes the AD713 ideal for high quality active filter
applications.
Lead Temperature Range (Soldering 60 sec) . . . . . . . . . . 300°C
NOTES
1
Stresses above those listed under “Absolute Maximum Ratings” may cause perma-
nent damage to the device. This is a stress rating only and functional operation of
the device at these or any other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.
For supply voltages less than ± 18 V, the absolute maximum input voltage is equal
to the supply voltage.
16-Pin SOIC Package:θJC = 30°C/
ORDERING GUIDE
ModelRangeDescriptionOption
AD713AQ–40°C to +85°C14-Pin Ceramic DIP Q-14
AD713BQ–40°C to +85°C14-Pin Ceramic DIP Q-14
AD713JN0°C to 70°C14-Pin Plastic DIPN-14
AD713JR-160°C to 70°C16-Pin Plastic SOIC R-16
AD713JR-16-REEL0°C to 70°C16-Pin Plastic SOIC R-16
AD713JR-16-REEL7 0°C to 70°C16-Pin Plastic SOIC R-16
AD713KN0°C to 70°C14-Pin Plastic DIPN-14
AD713SQ
AD713TQ
5962-9063301MCA–55°C to +125°C 14-Pin Ceramic DIP Q-14
5962-9063302MCA2–55°C to +125°C 14-Pin Ceramic DIP Q-14
1
N = Plastic DIP; Q = Cerdip; R = Small Outline IC (SOIC).
2
Not for new designs. Obsolete April 2002.
2
2
TemperaturePackagePackage
–55°C to +125°C 14-Pin Ceramic DIP Q-14
–55°C to +125°C 14-Pin Ceramic DIP Q-14
1
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection. Although
the AD713 features proprietary ESD protection circuitry, permanent damage may occur on devices
subjected to high-energy electrostatic discharges. Therefore, proper ESD precautions are
recommended to avoid performance degradation or loss of functionality.
REV. C
–3–
Page 4
AD713
–Typical Performance Characteristics
TPC 1. Input Voltage Swing vs.
Supply Voltage
TPC 4. Quiescent Current
vs. Supply Voltage
TPC 2. Output Voltage Swing vs.
Supply Voltage
TPC 5. Input Bias Current
vs. Temperature
TPC 3. Output Voltage Swing vs.
Load Resistance
TPC 6. Output Impedance vs.
Frequency, G = 1
TPC 7. Input Bias Current
vs. Common Mode Voltage
TPC 8. Short-Circuit Current Limit
vs. Temperature
–4–
TPC 9. Gain Bandwidth Product
vs. Temperature
REV. C
Page 5
Typical Performance Characteristics–AD713
TPC 10. Open-Loop Gain and
Phase Margin vs. Frequency
TPC 13. Common Mode Rejection
vs. Frequency
TPC 11. Open-Loop Gain vs.
Supply Voltage
TPC 14. Large Signal Frequency
Response
TPC 12. Power Supply Rejection
vs. Frequency
TPC 15. Output Swing and
Error vs. Settling Time
TPC 16. Total Harmonic Distortion
vs. Frequency
REV. C
TPC 17. Input Noise Voltage
Spectral Density
–5–
TPC 18. Slew Rate vs. Input
Error Signal
Page 6
AD713
TPC 19. Crosstalk Test Circuit
TPC 20. Crosstalk vs. Frequency
TPC 21a. Unity Gain Follower
TPC 22a. Unity Gain Inverter
TPC 21b. Unity Gain Follower
Pulse Response (Large Signal)
TPC 21c. Unity Gain Follower Pulse
Response (Small Signal)
TPC 22b. Unity Gain Inverter
Pulse Response (Large Signal)
TPC 22c. Unity Gain Inverter Pulse
Response (Small Signal)
–6–
REV. C
Page 7
AD713
MEASURING AD713 SETTLING TIME
The photos of Figures 2 and 3 show the dynamic response of
the AD713 while operating in the settling time test circuit of
Figure 1. The input of the settling time fixture is driven by a
flat-top pulse generator. The error signal output from the false
summing node of A1, the AD713 under test, is clamped, amplified by op amp A2 and then clamped again.
The error signal is thus clamped twice: once to prevent overloading amplifier A2 and then a second time to avoid overloading the
oscilloscope preamp. A Tektronix oscilloscope preamp type 7A26
was carefully chosen because it recovers from the approximately
0.4 V overload quickly enough to allow accurate measurement
of the AD713’s 1 µs settling time. Amplifier A2 is a very high
speed FET input op amp; it provides a voltage gain of 10, amplifying the error signal output of the AD713 under test (providing
an overall gain of 5).
Figure 3. Settling Characteristics to –10 V Step.
Upper Trace: Output of AD713 Under Test (5 V/div).
Lower Trace: Amplified Error Voltage (0.01%/ div)
Figure 1. Settling Time Test Circuit
Figure 2. Settling Characteristics 0 V to +10 V Step.
Upper Trace: Output of AD713 Under Test (5 V/div).
Lower Trace: Amplified Error Voltage (0.01%/div)
POWER SUPPLY BYPASSING
The power supply connections to the AD713 must maintain a
low impedance to ground over a bandwidth of 4 MHz or more.
This is especially important when driving a significant resistive
or capacitive load, since all current delivered to the load comes
from the power supplies. Multiple high quality bypass capacitors
are recommended for each power supply line in any critical
application. A 0.1 µF ceramic and a 1 µF electrolytic capacitor
as shown in Figure 4 placed as close as possible to the amplifier
(with short lead lengths to power supply common) will assure
adequate high frequency bypassing in most applications. A
minimum bypass capacitance of 0.1 µF should be used for any
application.
Figure 4. Recommended Power Supply Bypassing
REV. C
–7–
Page 8
AD713
A HIGH SPEED INSTRUMENTATION AMPLIFIER
CIRCUIT
The instrumentation amplifier circuit shown in Figure 5 can
provide a range of gains from unity up to 1000 and higher using
only a single AD713. The circuit bandwidth is 1.2 MHz at a
gain of 1 and 250 kHz at a gain of 10; settling time for the entire
circuit is less than 5 µs to within 0.01% for a 10 V step, (G = 10).
Other uses for amplifier A4 include an active data guard and an
active sense input.
A HIGH SPEED FOUR OP AMP CASCADED AMPLIFIER
CIRCUIT
Figure 7 shows how the four amplifiers of the AD713 may be
connected in cascade to form a high gain, high bandwidth amplifier. This gain of 100 amplifier has a –3 dB bandwidth greater
than 600 kHz.
Figure 7. A High Speed Four Op Amp Cascaded
Amplifier Circuit
Figure 5. A High Speed Instrumentation Amplifier Circuit
Table I provides a performance summary for this circuit. The
photo of Figure 6 shows the pulse response of this circuit for a
gain of 10.
Table I. Performance Summary for the High Speed
Instrumentation Amplifier Circuit
Figure 6. The Pulse Response of the High Speed
Instrumentation Amplifier. Gain = 10
Figure 8. THD Test Circuit
HIGH SPEED OP AMP APPLICATIONS AND
TECHNIQUES
DAC Buffers (I-to-V Converters)
The wide input dynamic range of JFET amplifiers makes them
ideal for use in both waveform reconstruction and digital-audio
DAC applications. The AD713, in conjunction with the AD1860
DAC, can achieve 0.0016% THD (here at a 4fs or a 176.4 kHz
update rate) without requiring the use of a deglitcher. Just such
a circuit is shown in Figure 9. The 470 pF feedback capacitor
used with IC2a, along with op amp IC2b and its associated
components, together form a 3-pole low-pass filter. Each or all
of these poles can be tailored for the desired attenuation and
phase characteristics required for a particular application. In this
application, one half of an AD713 serves each channel in a twochannel stereo system.
–8–
REV. C
Page 9
Figure 9. A D/A Converter Circuit for Digital Audio
AD713
Figure 10. Harmonic Distortion as Frequency for the
Digital Audio Circuit of Figure 9
Driving the Analog Input of an A/D Converter
An op amp driving the analog input of an A/D converter, such
as that shown in Figure 11, must be capable of maintaining a
constant output voltage under dynamically changing load conditions. In successive approximation converters, the input current
is compared to a series of switched trial currents. The comparison point is diode clamped but may vary by several hundred
millivolts, resulting in high frequency modulation of the A/D
input current. The output impedance of a feedback amplifier is
made artificially low by its loop gain. At high frequencies, where
the loop gain is low, the amplifier output impedance can approach its open loop value.
REV. C
–9–
Figure 11. The AD713 as an ADC Buffer
Most IC amplifiers exhibit a minimum open loop output imped-
ance of 25 Ω, due to current limiting resistors. A few hundred
microamps reflected from the change in converter loading can
introduce errors in instantaneous input voltage. If the A/D conversion speed is not excessive and the bandwidth of the amplifier
is sufficient, the amplifier’s output will return to the nominal
value before the converter makes its comparison. However,
many amplifiers have relatively narrow bandwidths, yielding
slow recovery from output transients. The AD713 is ideally
suited as a driver for A/D converters since it offers both a wide
bandwidth and a high open loop gain.
Page 10
AD713
Figure 12. Buffer Recovery Time Source Current = 2 mA
Figure 13. Buffer Recovery Time Sink Current = 1 mA
Driving A Large Capacitive Load
The circuit of Figure 14 employs a 100 Ω isolation resistor which
enables the amplifier to drive capacitive loads exceeding 1500 pF;
the resistor effectively isolates the high frequency feedback from
the load and stabilizes the circuit. Low frequency feedback is
returned to the amplifier summing junction via the low pass filter
formed by the 100 Ω series resistor and the load capacitance, C1.
Figure 15 shows a typical transient response for this connection.
The AD713 is an excellent output amplifier for CMOS DACs.
It can be used to perform both 2 and 4 quadrant operation. The
output impedance of a DAC using an inverted R-2R ladder
approaches R for codes containing many “1”s, 3R for codes containing a single “1” and infinity for codes containing all zeros.
For example, the output resistance of the AD7545 will modu-
late between 11 kΩ and 33 kΩ. Therefore, with the DAC’s
internal feedback resistance of 11 kΩ, the noise gain will vary
from 2 to 4/3. This changing noise gain modulates the effect of
the input offset voltage of the amplifier, resulting in nonlinear
DAC amplifier performance. The AD713, with its guaranteed
Figures 16 and 17 show the AD713 and a 12-bit CMOS DAC,
the AD7545, configured for either a unipolar binary (2-quadrant
multiplication) or bipolar (4-quadrant multiplication) operation.
Capacitor C1 provides phase compensation which reduces overshoot and ringing.
Figure 14. Circuit for Driving a Large Capacitance Load
Table II. Recommended Trim Resistor Values vs.
Grades for AD7545 for V
TrimJN/AQ/KN/BQ/LN/CQ/GLN/GCQ/
ResistorSDTDUDGUD
R1500 Ω200 Ω100 Ω20 Ω
R2150 Ω68 Ω33 Ω6.8 Ω
= 5 V
D
–10–
Figure 16. Unipolar Binary Operation
Figure 17. Bipolar Operation
REV. C
Page 11
Figure 18. A Programmable State Variable Filter Circuit
AD713
FILTER APPLICATIONS
A Programmable State Variable Filter
For the state variable or universal filter configuration of Figure
18 to function properly, DACs A1 and B1 need to control the
gain and Q of the filter characteristic, while DACs A2 and B2
must accurately track for the simple expression of f
to be true.
C
This is readily accomplished using two AD7528 DACs and one
AD713 quad op amp. Capacitor C3 compensates for the effects
of op amp gain-bandwidth limitations.
This filter provides low pass, high pass and band pass outputs
and is ideally suited for applications where microprocessor
control of filter parameters is required. The programmable
range for component values shown is f
= 0 to 15 kHz and
C
Q = 0.3 to 4.5.
GIC and FDNR FILTER APPLICATIONS
The closely matched and uniform ac characteristics of the
AD713 make it ideal for use in GIC (gyrator) and FDNR (frequency dependent negative resistor) filter applications. Figures
19 and 21 show the AD713 used in two typical active filters.
The first shows a single AD713 simulating two coupled inductors
configured as a one-third octave bandpass filter. A single section
of this filter meets ANSI class II specifications and handles a
7.07 V rms signal with <0.002% THD (20 Hz–20 kHz).
Figure 21 shows a 7-pole antialiasing filter for a 2 ⫻ oversampling (88.2 kHz) digital audio application. This filter has <0.05
dB pass band ripple and 19.8 ±0.3 µs delay, dc-20 kHz and will
handle a 5 V rms signal (V
= ±15 V) with no overload at any
S
internal nodes.
The filter of Figure 19 can be scaled for any center frequency by
using the formula:
1.11
f
=
C
2πRC
where all resistors and capacitors scale equally. Resistors R3–R8
should not be greater than 2 kΩ in value, to prevent parasitic
oscillations caused by the amplifier’s input capacitance.
REV. C
Figure 19. A 1/3 Octave Filter Circuit
–11–
Page 12
AD713
If this is not practical, small lead capacitances (10–20 pF)
should be added across R5 and R6. Figures 20 and 22 show the
output amplitude vs. frequency of these filters.
Figure 20. Output Amplitude vs. Frequency of 1/3
Octave Filter
Figure 21. An Antialiasing Filter
Figure 22. Relative Output Amplitude vs. Frequency