Analog Devices AD845SQ-883B, AD845SQ, AD845SCHIPS, AD845KN, AD845JR-16-REEL7 Datasheet

Precision, 16 MHz

a

FEATURES
Replaces Hybrid Amplifiers in Many Applications

AC PERFORMANCE:
Settles to 0.01% in 350 ns
100 V/ms Slew Rate

12.8 MHz min Unity-Gain Bandwidth

1.75 MHz Full-Power Bandwidth at 20 V p-p
DC PERFORMANCE:

0.25 mV max Input Offset Voltage
5 mV/8C max Offset Voltage Drift

0.5 nA Input Bias Current
250 V/mV min Open-Loop Gain
4 mV p-p max Voltage Noise, 0.1 Hz to 10 Hz
94 dB min CMRR
Available in Plastic Mini-DIP, Hermetic Cerdip and

SOIC Packages. Also Available in Tape and Reel in
Accordance with EIA-481A Standard

PRODUCT DESCRIPTION

The AD845 is a fast, precise, N channel JFET input, monolithic
operational amplifier. It is fabricated using Analog Devices’
complementary bipolar (CB) process. Advanced laser-wafer
trimming technology enables the very low input offset voltage
and offset voltage drift performance to be realized. This preci­sion, when coupled with a slew rate of 100 V/µs, a stable
unity-gain bandwidth of 16 MHz, and a settling time of 350 ns

0.01%—while driving a parallel load of 100 pF and 500 Ω—
represents a combination of features unmatched by any FET
input IC amplifier. The AD845 can easily be used to upgrade
many existing designs which use BiFET or FET input hybrid
amplifiers and, in some cases, those which use bipolar input op
amps.

The AD845 is ideal for use in applications such as active filters,
high speed integrators, photo diode preamps, sample-and-hold
amplifiers, log amplifiers, and in buffering A/D and D/A con­verters. The 250 µV max input offset voltage makes offset null-
ing unnecessary in many applications. The common-mode
rejection ratio of 110 dB over a ± 10 V input voltage range
represents exceptional performance for a JFET input high
speed op amp. This, together with a minimum open-loop
gain of 250 V/mV ensures that 12-bit performance is achieved,
even in unity-gain buffer circuits.

CBFET Op Amp

AD845

CONNECTION DIAGRAMS

Plastic Mini-DIP (N) Package

and Cerdip (Q) Package

The AD845 conforms to the standard op amp pinout except
that offset nulling is to V+. The AD845J and AD845K grade
devices are available specified to operate over the commercial
0°C to +70°C temperature range. AD845A and AD845B
devices are specified for operation over the –40°C to +85°C
industrial temperature range. The AD845S is specified to oper­ate over the full military temperature range of –55°C to
+125°C. Both the industrial and military versions are available
in 8-pin cerdip packages. The commercial version is available in
an 8-pin plastic mini-DIP and 16-pin SOIC; “J” and “S” grade
chips are also available.

PRODUCT HIGHLIGHTS

1. The high slew rate, fast settling time, and dc precision of the
AD845 make it ideal for high speed applications requiring
12-bit accuracy.

2. The performance of circuits using the LF400, HA2520/2/5,
HA2620/2/5, 3550, OPA605, and LH0062 can be upgraded
in most cases.

3. The AD845 is unity-gain stable and internally compensated.

4. The AD845 is specified while driving 100 pF/500 Ω loads.

16-Pin SOIC

(R-16) Package

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.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] Fax: [phone]

AD845–SPECIFICA TIONS

(@ +258C and 615 V dc, unless otherwise noted)

Model AD845J/A AD845K/B AD845S

Conditions Min Typ Max Min Typ Max Min Typ Max Units

INPUT OFFSET VOLTAGE

1

Initial Offset 0.7 1.5 0.1 0.25 0.25 1.0 mV

T

MIN–TMAX

2.5 0.4 2.0 mV

Offset Drift 20 1.5 5.0 10 µV/°C

INPUT BIAS CURRENT

2

Initial VCM = 0 V 0.75 2 0.5 1 0.75 2 nA

T

MIN–TMAX

45/75 18/38 500 nA

INPUT OFFSET CURRENT

Initial VCM = 0 V 25 300 15 100 25 300 pA

T

MIN–TMAX

INPUT CHARACTERISTICS

Input Resistance 10

11

3/6.5 1.2/2.6 20 nA

10

11

10

11

kΩ

Input Capacitance 4.0 4.0 4.0 pF

INPUT VOLTAGE RANGE

Differential ±20 ±20 ±20 V
Common Mode 610 +10.5/–13 610 +10.5/–13 610 +10.5/–13 V
Common-Mode Rejection VCM = ±10 V 86 110 94 113 86 110 dB

INPUT VOLTAGE NOISE 0.1 Hz to 10 Hz 4 4 4 µV p-p

f = 10 Hz 80 80 80 nV/√Hz
f = 100 Hz 60 60 60 nV/√Hz
f = 1 kHz 25 25 25 nV/√Hz
f = 10 kHz 18 18 18 nV/√Hz

f = 100 kHz 12 12 12 nV/√Hz
INPUT CURRENT NOISE f = 1 kHz 0.1 0.1 0.1 pA/√Hz
OPEN-LOOP GAIN VO = ±10 V

R

≥ 2 kΩ 200 500 250 500 200 500 V/mV

LOAD

R

≥ 500 Ω 100 250 125 250 100 250 V/mV

LOAD

T

MIN–TMAX

70 75 50 V/mV

OUTPUT CHARACTERISTICS

Voltage R

≥ 500 Ω 612.5 612.5 612.5 V

LOAD

Current Short Circuit 50 50 50 mA
Output Resistance Open Loop 5 5 5 Ω

FREQUENCY RESPONSE

Small Signal Unity Gain 12.8 16 13.6 16 13.6 16 MHz
Full Power Bandwidth

3

VO = ±10 V

R

= 500 Ω 1.75 1.75 1.75 MHz

LOAD

Rise Time 20 20 20 ns
Overshoot 20 20 20 %
Slew Rate 80 100 94 100 94 100 V/µs
Settling Time 10 V Step

C

= 100 pF

LOAD

R

= 500 Ω

LOAD

to 0.01% 350 350 500 350 500 ns

to 0.1% 250 250 250 ns
DIFFERENTIAL GAIN f = 4.4 MHz 0.04 0.04 0.04 %
DIFFERENTIAL PHASE f = 4.4 MHz 0.02 0.02 0.02 Degree
POWER SUPPLY

Rated Performance ± 15 ±15 ±15 V
Operating Range 64.75 618 64.75 618 64.75 618 V
Rejection Ratio VS = ±5 to ±15 V 88 110 95 113 88 110 dB
Quiescent Current T

NOTES

1

Input offset voltage specifications are guaranteed after 5 minutes of operation at TA = +25°C.

2

Bias current specifications are guaranteed maximum at either input after 5 minutes of operation at T

3

FPBW = slew rate/2 π V peak.

4

“S” grade T

All min and max specifications are guaranteed. Specifications shown in boldface are tested on all production units at final electrical test. Results from these tests are
used to calculate outgoing quality levels.
Specifications subject to change without notice.

MIN–TMAX

are tested with automatic test equipment at TA = –55°C and TA = +125°C.

MIN

to T

MAX

10 12 10 12 10 12 mA

= +25°C.

A

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REV. D

AD845

ABSOLUTE MAXIMUM RATINGS

Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±18 V

Internal Power Dissipation

2

1

Plastic Mini-DIP . . . . . . . . . . . . . . . . . . . . . . . . . .1.6 Watts

Cerdip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.4 Watts

16-Pin SOIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.5 Watts

Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . + V

S

Output Short-Circuit Duration . . . . . . . . . . . . . . . . Indefinite

Differential Input Voltage . . . . . . . . . . . . . . . . . . +V

and –V

S

S

Storage Temperature Range

Q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .–65°C to +150°C

N, R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .–65°C to +125°C

Lead Temperature Range (Soldering 60 sec) . . . . . . . . +300°C

NOTES

1

Stresses above those listed under “Absolute Maximum Ratings” may cause
permanent 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 sections of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability .

2

Mini-DIP package: θJA = 100°C/watt; cerdip package: θJA = 110°C/watt. SOIC
package: θJA = 100°C/W.

ORDERING GUIDE

Temperature Package Package

Model Range Description Option*

METALIZATION PHOTOGRAPH

Dimensions shown in inches and (mm).

Contact factory for latest dimensions.

SUBSTRATE CONNECTED TO +V

S

AD845JN 0°C to +70°C 8-Pin Plastic Mini-DIP N-8
AD845KN 0°C to +70°C 8-Pin Plastic Mini-DIP N-8
AD845JR-16 0°C to +70°C 16-Pin SOIC R-16
AD845AQ –40°C to +85°C 8-Pin Cerdip Q-8
AD845BQ –40°C to +85°C 8-Pin Cerdip Q-8
AD845SQ –55°C to +125°C 8-Pin Cerdip Q-8
AD845SQ/883B –55°C to +125°C 8-Pin Cerdip Q-8
5962-8964501PA –55°C to +125°C 8-Pin Cerdip Q-8
AD845JCHIPS 0°C to +70°C Die
AD845SCHIPS –55°C to +125°C Die
AD845JR-16-REEL 0°C to +70°C Tape & Reel
AD845JR-16-REEL7 0°C to +70°C Tape & Reel

REV. D

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