Analog Devices AD846 Datasheet

450 V/s, Precision,

a

FEATURES

AC PERFORMANCE
Small Signal Bandwidth: 80 MHz (A
Slew Rate: 450 V/s
Full Power Bandwidth: 6.8 MHz at 20 V p-p,

= 500 

R

L

Fast Settling: for 10 V Step: 110 ns to 0.01%,

80 ns to 0.1%
Differential Gain: <0.01% @ 4.4 MHz
Differential Phase: <0.028 @ 4.4 MHz
Total Harmonic Distortion (THD): 0.0005% @ 100 kHz
Open-Loop Transimpedance: 200 M
Input Voltage Noise: 2 nV/√Hz

DC PERFORMANCE
Input Offset Voltage: 75 V max (B Grade)
Input Offset Drift: 3.5 V/C max (B Grade)
Quiescent Supply Current: 6.5 mA max

APPLICATIONS
High Speed DAC Buffers
Multiflash ADC Error Amplifiers
Flash ADC Buffers
Coaxial Cable Drivers
High Performance Audio Circuitry
Available in Plastic Mini-DIP, Hermetic Cerdip, and

Plastic SOIC (A) Package
MIL-STD-883B Part Available

PRODUCT DESCRIPTION

The AD846 is a monolithic, very high speed operational ampli­fier offering high performance. Although technically classed as a
current-feedback or transimpedance amplifier, it may be used
in much the same way as traditional op amps while providing
significant performance benefits. Employing Analog Devices’
junction isolated complementary bipolar (CB) process, the AD846
achieves true “12-bit” (0.01%) precision on critical ac and dc
parameters, a level of performance unmatched by amplifiers
fabricated using either the dielectrically isolated (DI) or other
bipolar processes.

The AD846 offers significant advantages over conventional
high speed operational amplifiers. It maintains a nearly con­stant bandwidth and settling time to 0.01% over a wide range
of closed-loop gains. This makes the AD846 ideal for amplifying
the residue in multiple-pass analog-to-digital converters.

Other advantages include: low input errors and high open-loop
transresistance (200 MΩ) into a 500 Ω load, ensuring true
12-bit dc accuracy for closed-loop gains from –1 to gains
greater than –100. This combination of ac and dc perfor­mance makes the AD846 an excellent choice for buffering
precision high speed DACs and flash ADCs.

= –1)

V

Current-Feedback Op Amp

AD846

CONNECTION DIAGRAMS

Plastic Mini-DIP (N) Package

and

Cerdip (Q) Package

SOIC (R) Package

1

NC

AD846

2

NC

–

3

–INPUT

4

NC

+INPUT

NC

–V

NC

+

5

6

TOP VIEW

(Not to Scale)

7

S

8

NC = NO CONNECT

The AD846 is available in three performance grades. The AD846A
and AD846B are rated over the industrial temperature range
of –40°C to +85°C. The AD846S is rated over the full mili­tary temperature range of –55°C to +125°C and is available
processed to MIL-STD-883B, Rev C.

The AD846 is available in two types of 8-lead packages: plastic
mini-DIP and hermetic cerdip. The AD846AR-16 is available in
the 16-lead SOIC package. “A” and “S” grade chips are also
available.

PRODUCT HIGHLIGHTS

1. The AD846 achieves settling times of 110 ns to 0.01%

for gains of –1 to –10, with a 450 V/µs slew rate, while
consuming only 5 mA of supply current.

2. For closed-loop gains of –1 to –100, the high speed perfor­mance of the AD846 is achieved without sacrificing full 12-bit
dc precision.

3. The AD846 is well suited to line driver and video buffer
applications where the properties of low distortion and high
slew rate are required.

16

NC

15

NC

+V

14

S

13

NC

12

OUTPUT

11

COMPENSATION

10

NC

9

NC

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
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] World Wide Web Site: http://www.analog.com
Fax: [phone] © Analog Devices, Inc., 2000

AD846–SPECIFICATIONS

(@ +25C and 15 V dc, unless otherwise noted)

Model Conditions Min Typ Max Min Typ Max Min Typ Max Units

AD846A AD846B AD846S

INPUT OFFSET VOLTAGE

1

Initial 25 200 25 75 25 200 µV
T

MIN–TMAX

vs. Temperature 0.8 5 0.8 3.5 1 5.5 µV/°C
vs. Supply (PSRR) 5 V–18 V

2

50 350 50 125 100 350 µV

Initial 110 125 120 125 110 125 dB
T

MIN–TMAX

vs. Common Mode (CMRR) VCM = ±10 V

110 120 116 120 94 116 dB

Initial 110 125 120 125 110 125 dB
T

MIN–TMAX

INPUT BIAS CURRENT

3

110 120 116 120 94 116 dB

–Input Bias Current

Initial 150 450 100 250 150 450 nA
T

MIN–TMAX

vs. Temperature 6 20 6 17 9 20 nA/°C
vs. Supply 5 V–18 V

2

450 1200 400 750 1000 1500 nA

Initial 9 15 9 10 9 15 nA/V
T

MIN–TMAX

vs. Common Mode VCM = ±10 V

11 20 11 15 11 25 nA/V

Initial 5 10 3 5 5 10 nA/V
T

MIN–TMAX

+Input Bias Current

515 37 5 20 nA/V

Initial 3 15 3 5 3 15 µA
T

MIN–TMAX

vs. Temperature 15 80 15 45 15 80 nA/°C
vs. Supply 5 V–18 V

2

420 47 5 20 µA

Initial 5 15 5 10 5 15 nA/V
T

MIN–TMAX

vs. Common Mode VCM = ±10 V

520 515 5 20 nA/V

Initial 5 15 3 10 5 15 nA/V
T

MIN–TMAX

515 310 5 20 nA/V

INPUT CHARACTERISTICS

Input Resistance

–Input 50 50 50 Ω

+Input 10 10 10 kΩ

Input Capacitance

–Input 2 2 2 pF

+Input 2 2 2 pF

INPUT VOLTAGE RANGE

Common Mode ±10 ±10 ±10 V

INPUT VOLTAGE NOISE F = 1 kHz 2 2 2 nV/√Hz

Input Current Noise

–Input 1 kHz 20 20 20 pA/√Hz
+Input 1 kHz 6 6 6 pA/√Hz

OPEN LOOP

TRANSRESISTANCE V

= ±10 V

OUT

R

= 500 Ω 100 200 150 200 100 200 MΩ

LOAD

T

MIN–TMAX

50 75 50 MΩ

OUTPUT CHARACTERISTICS

Voltage R
Current Short Circuit 65 65 65 mA

= 500 Ω 10 10 10 V

LOAD

Output Resistance Open Loop 16 16 16 Ω

FREQUENCY RESPONSE

Small Signal Bandwidth AV = –1 RF = 1k 80 80 80 MHz

(–3 dB) AV = –10 RF = 875 Ω 31 31 31 MHz

Full Power Bandwidth

4

AV = –30 RF = 875 Ω 15 15 15 MHz
V

= 20 V p-p

OUT

RI = 500 Ω 6.8 6.8 6.8 MHz
Rise Time AV = –1 110 10 10 ns
Overshoot AV = –1 20 20 20 %
Slew Rate AV = –1 450 450 450 V/µs
Settling Time

10 V Step, AV = –1 to 0.1% 80 80 80 ns

to 0.01% 110 110 110 ns

TOTAL HARMONIC

DISTORTION

5

F = 100 kHz 0.0005 0.0005 0.0005 %

–2–

REV. C

AD846

Model Conditions Min Typ Max Min Typ Max Min Typ Max Units

DIFFERENTIAL GAIN F = 4.4 MHz, RL = 100 Ω 0.01 0.01 0.01 %

DIFFERENTIAL PHASE F = 4.4 MHz, RL = 100 Ω 0.028 0.028 0.028 Degrees

POWER SUPPLY

Rated Performance ±15 ± 15 ± 15 V
Operating Range ±5 18 ±5 18 5 18 V

Quiescent Current T

TRANSISTOR COUNT 72 72 72

NOTES

1

Input Offset Voltage Specifications are guaranteed after 5 minutes at TA = +25°C.

2

Test Conditions: +VS = 15 V, –VS = 5 V to 18 V and +VS = 5 V to 18 V, –VS = 15 V.

3

Bias Current Specifications are guaranteed maximum after 5 minutes at TA = +25°C.

4

FPBW = Slew Rate/2 π V

5

Total Harmonic Distortion.

All min and max specifications are guaranteed. Specifications shown in boldface are tested on all production units at final electrical test. Results from those tests are
used to calculate outgoing quality levels.

Specifications subject to change without notice.

PEAK

.

ABSOLUTE MAXIMUM RATINGS

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

Internal Power Dissipation

2

MIN–TMAX

1

Plastic Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5 W

Cerdip Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 W

Common-Mode Input Voltage, Max Safe . . . . . . . |V

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

Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . . ±1 V

Continuous Input Current

Inverting or Noninverting . . . . . . . . . . . . . . . . . . . . 2.0 mA

Storage Temperature Range (Q) . . . . . . . . . –65°C to +150°C

Storage Temperature Range (N) . . . . . . . . . –65°C to +125°C

Storage Temperature Range (R) . . . . . . . . . –65°C to +125°C

Operating Temperature Range

AD846A/B . . . . . . . . . . . . . . . . . . . . . . . . –40°C to +85°C

AD846S . . . . . . . . . . . . . . . . . . . . . . . . . . –55°C to +125°C

AD846A AD846B AD846S

5 6.5 5 6.5 5 7 mA

ORDERING GUIDE

1

Model

Temperature Range Option

AD846AN –40°C to +85°C N-8

| – 3 V

S

AD846BN –40°C to +85°C N-8
AD846AQ –40°C to +85°C Q-8
AD846BQ –40°C to +85°C Q-8
AD846SQ –55°C to +125°C Q-8
AD846SQ/883B –55°C to +125°C Q-8
5962-8964601PA –55°C to +125°C Q-8
AD846AR-16 –40°C to +85°C R-16
AD846AR-16-REEL –40°C to +85°C R-16

NOTES

1

“A” and “S” grade chips are also available.

2

N = Plastic DIP Package; Q = Cerdip Package, R = SOIC Package

Package

2

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

ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3500 V

NOTES

1

Stresses above those listed under Absolute Maximum Ratings may cause perma-

nent damage to the device. This is a stress rating only; the 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

Maximum internal power dissipation is specified so that TJ does not exceed

+175°C at an ambient temperature of +25°C, derate cerdip (Q) package at

8.7 mW/°C and plastic (N) package at 10 mW/°C.
Plastic Package: θJA = 100°C/Watt, θJC = 33°C/W.
Cerdip Package: θJA = 110°C/Watt, θJC = 30°C/W.
SOIC Package: θJA = 100°C/Watt, θJC = 33°C/W.

METALIZATION PHOTOGRAPH

Dimensions shown in inches and (mm).

Consult factory for latest dimensions.

REV. C

–3–

AD846 – Typical Characteristics

Figure 1. Input Voltage Swing
vs. Supply

Figure 4. Quiescent Supply Current
vs. Temperature

Figure 2. Output Voltage Swing
vs. Supply

Figure 5. Output Voltage Swing vs.
Resistive Load

Figure 3. Quiescent Current vs.
Supply Voltage

Figure 6. Large Signal Frequency
Response

Figure 7. Open-Loop Transimpedance
vs. Supply

Figure 8. Positive Input Bias Current
vs. Common-Mode Voltage

–4–

Figure 9. Negative Input Bias

Current vs. Common-Mode Voltage

REV. C