Dual Picoampere Input
Current Bipolar Op Amp
a
AD706
FEATURE
CO NNECTIO N D IAGRAM
HIGH DC PRECISION
P lastic Mini-D IP (N)
Cerdip (Q) and
P lastic SO IC (R) P ackages
50 V m ax Offset Voltage
0.6 V/ ؇C m ax Offset Drift
110 pA m ax Input Bias Current
LOW NOISE
0.5 V p-p Voltage Noise, 0.1 Hz to 10 Hz
AMPLIFIER 1
AMPLIFIER 2
AD706
OUTPUT
–IN
1
2
3
4
8
7
6
5
V؉
LOW POWER
750 A Supply Current
Available in 8-Lead Plastic Mini-DlP, Herm etic Cerdip
and Surface Mount (SOIC) Packages
Available in Tape and Reel in Accordance w ith
EIA-481A Standard
OUTPUT
–IN
؉IN
V–
؉IN
TOP VIEW
Single Version: AD705, Quad Version: AD704
PRIMARY APPLICATIONS
Low Frequency Active Filters
Precision Instrum entation
Precision Integrators
T he AD706 is offered in three varieties of an 8-lead package:
plastic mini-DIP, hermetic cerdip and surface mount (SOIC).
“J” grade chips are also available.
P RO D UCT D ESCRIP TIO N
P RO D UCT H IGH LIGH TS
T he AD706 is a dual, low power, bipolar op amp that has the
low input bias current of a BiFET amplifier, but which offers a
significantly lower IB drift over temperature. It utilizes superbeta
bipolar input transistors to achieve picoampere input bias cur-
rent levels (similar to FET input amplifiers at room tempera-
ture), while its IB typically only increases by 5× at 125°C (unlike
a BiFET amp, for which IB doubles every 10°C for a 1000×
increase at 125°C). T he AD706 also achieves the microvolt
offset voltage and low noise characteristics of a precision bipolar
input amplifier.
1. T he AD706 is a dual low drift op amp that offers BiFET
level input bias currents, yet has the low IB drift of a bipolar
amplifier. It may be used in circuits using dual op amps such
as the LT 1024.
2. T he AD706 provides both low drift and high dc precision.
3. T he AD706 can be used in applications where a chopper
amplifier would normally be required but without the
chopper’s inherent noise.
100
Since it has only 1/20 the input bias current of an OP07, the
AD706 does not require the commonly used “balancing” resis-
tor. Furthermore, the current noise is 1/5 that of the OP07,
which makes this amplifier usable with much higher source
impedances. At 1/6 the supply current (per amplifier) of the
OP07, the AD706 is better suited for today’s higher density
boards.
10
TYPICAL JFET AMP
1
T he AD706 is an excellent choice for use in low frequency
active filters in 12- and 14-bit data acquisition systems, in preci-
sion instrumentation and as a high quality integrator. T he
AD706 is internally compensated for unity gain and is available
in five performance grades. T he AD706J and AD706K are rated
over the commercial temperature range of 0°C to +70°C. T he
AD706A and AD706B are rated over the industrial temperature
range of –40°C to +85°C.
0.1
AD706
0.01
–55
+25
+110
+125
TEMPERATURE – ؇C
Figure 1. Input Bias Current vs. Tem perature
REV. C
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which m ay result from its use. No license is granted by im plication or
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