Analog Devices OP285GP, OP285GSR, OP285GS Datasheet

REV. A

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.

a

OP285

*

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] © Analog Devices, Inc., 2001

Dual 9 MHz Precision

Operational Amplifier

PIN CONNECTIONS

8-Lead Narrow-Body SO (S-Suffix)

TOP VIEW

(Not to Scale)

OP285

–IN A

+IN A

V–

OUT A

V+

–IN B

+IN B

OUT B

8

7

6

5

1

2

3

4

8-Lead Epoxy DIP (P-Suffix)

8

7

6

5

V+

–IN B

+IN B

OUT B

1

2

3

4

–IN A

+IN A

V–

OUT A

+–

+–

OP285

The combination of low noise, speed and accuracy can be used
to build high speed instrumentation systems. Circuits such as
instrumentation amplifiers, ramp generators, bi-quad filters and
dc-coupled audio systems are all practical with the OP285. For
applications that require long term stability, the OP285 has a
guaranteed maximum long term drift specification.

The OP285 is specified over the XIND—extended industrial—
(–40°C to +85°C) temperature range. OP285s are available in
8-pin plastic DIP and SOIC-8 surface mount packages.

FEATURES
Low Offset Voltage: 250 V
Low Noise: 6 nV/√ Hz
Low Distortion: 0.0006%
High Slew Rate: 22 V/s
Wide Bandwidth: 9 MHz
Low Supply Current: 5 mA
Low Offset Current: 2 nA
Unity-Gain Stable
SO-8 Package

APPLICATIONS
High Performance Audio
Active Filters
Fast Amplifiers
Integrators

GENERAL DESCRIPTION

The OP285 is a precision high-speed amplifier featuring the
Butler Amplifier front-end. This new front-end design com­bines the accuracy and low noise performance of bipolar
transistors with the speed of JFETs. This yields an amplifier
with high slew rates, low offset and good noise performance
at low supply currents. Bias currents are also low compared
to bipolar designs.

The OP285 offers the slew rate and low power of a JFET
amplifier combined with the precision, low noise and low
drift of a bipolar amplifier. Input offset voltage is laser-trimmed
and guaranteed less than 250 µV. This makes the OP285 useful
in dc-coupled or summing applications without the need for
special selections or the added noise of additional offset
adjustment circuitry. Slew rates of 22 V/µs and a bandwidth
of 9 MHz make the OP285 one of the most accurate medium
speed amplifiers available.

*Patents pending

REV. A

–2–

OP285–SPECIFICATIONS

(@ Vs = 15.0 V, TA = 25C, unless otherwise noted.)

Parameter Symbol Conditions Min Typ Max Unit

INPUT CHARACTERISTICS

Offset Voltage V

OS

35 250 µV

V

OS

–40°C ≤ TA ≤ +85°C 600 µV

Input Bias Current I

B

VCM = 0 V 100 350 nA

I

B

VCM = 0 V, –40°C ≤ TA ≤ +85°C 400 nA

Input Offset Current I

OS

VCM = 0 V 2 ±50 nA

I

OS

VCM = 0 V, –40°C ≤ TA ≤ +85°C2±100 nA

Input Voltage Range V

CM

–10.5 10.5 V

Common-Mode Rejection CMRR V

CM

= ±10.5 V,

–40°C ≤ T

A

≤ +85°C 80 106 dB

Large-Signal Voltage Gain A

VO

RL = 2 kΩ 250 V/mV

A

VO

RL = 2 kΩ, –40°C ≤ TA ≤ +85°C 175 V/mV

A

VO

RL = 600 Ω 200 V/mV
Common-Mode Input Capacitance 7.5 pF
Differential Input Capacitance 3.7 pF
Long-Term Offset Voltage ∆V

OS

Note 1 300 µV
Offset Voltage Drift ∆V

OS

/∆T1µV/°C

OUTPUT CHARACTERISTICS

Output Voltage Swing V

O

RL = 2 kΩ –13.5 +13.9 +13.5 V

V

O

RL = 2 kΩ, –40°C ≤ TA ≤ +85°C –13 +13.9 +13 V

RL = 600 Ω, V

S

= ±18 V –16/+14 V

POWER SUPPLY

Power Supply Rejection Ratio PSRR V

S

= ±4.5 V to ±18 V 85 111 dB

PSRR V

S

= ±4.5 V to ±18 V,

–40°C ≤ T

A

≤ +85°C80 dB

Supply Current I

SY

VS = ±4.5 V to ±18 V, VO = 0 V,

R

L

= x, –40°C ≤ TA ≤ +85°C45mA

I

SY

VS = ±22 V, VO, = 0 V, RL = x

–40°C ≤ T

A

≤ +85°C 5.5 mA

Supply Voltage Range VS ±4.5 ± 22 V

DYNAMIC PERFORMANCE

Slew Rate SR R

L

= 2 kΩ 15 22 V/µs

Gain Bandwidth Product GBP 9 MHz
Phase Margin ␪o 62 Degrees
Settling Time t

s

To 0.1%, 10 V Step 625 ns

t

s

To 0.01%, 10 V Step 750 ns
Distortion A

V

= 1, V

OUT

= 8.5 V p-p,

f = 1 kHz, R

L

= 2 kΩ –104 dB

Voltage Noise Density e

n

f = 30 Hz 7 nV/√Hz

e

n

f = 1 kHz 6 nV/√Hz
Current Noise Density i

n

f = 1 kHz 0.9 pA/√Hz
Headroom THD + Noise ≤ 0.01%,

RL = 2 kΩ, VS = ±18 V >12.9 dBu

NOTE

1

Long-term offset voltage is guaranteed by a 1,000 hour life test performed on three independent wafer lots at 125 °C, with an LTPD of 1.3.

Specifications subject to change without notice.

REV. A

–3–

OP285

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 OP285 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.

WARNING!

ESD SENSITIVE DEVICE

ABSOLUTE MAXIMUM RATINGS

1

Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±22 V

Input Voltage

2

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±18 V

Differential Input Voltage

2

. . . . . . . . . . . . . . . . . . . . . . ±7.5 V

Output Short-Circuit Duration to Gnd

3

. . . . . . . . . Indefinite

Storage Temperature Range

P, S Package . . . . . . . . . . . . . . . . . . . . . . . –65°C to +150°C

Operating Temperature Range

OP285G . . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to +85°C

Junction Temperature Range

P, S Package . . . . . . . . . . . . . . . . . . . . . . . –65°C to +150°C

Lead Temperature Range (Soldering 60 Sec) . . . . . . . . 300°C

Package Type 

JA

4



JC

Unit

8-Pin Plastic DIP (P) 103 43 °C/W
8-Pin SOIC (S) 158 43 °C/W

NOTES

1

Absolute Maximum Ratings apply to packaged parts, unless otherwise noted.

2

For supply voltages less than ± 7.5 V, the absolute maximum input voltage is
equal to the supply voltage.

3

Shorts to either supply may destroy the device. See data sheet for full details.

4

␪JA is specified for the worst case conditions, i.e., ␪JA is specified for device in

socket for cerdip, P-DIP, and LCC packages; ␪JA is specified for device soldered
in circuit board for SOIC package.

ORDERING GUIDE

Temperature Package Package

Model Range Description Option

OP285GP* –40°C to +85°C 8-Pin Plastic DIP N-8
OP285GS –40°C to +85°C 8-Pin SOIC S0-8
OP285GSR –40°C to +85°C S0-8 Reel, 2500 pcs.

*Not for new designs. Obsolete April 2002.

REV. A

OP285

–4–

25

–25

–10

–20

–15

5

–5

0

10

15

20

OUTPUT VOLTAGE SWING – V

SUPPLY VOLTAGE – V

+VOM

–VOM

0 5 10 15 20 25

T

A

= 25C

R

L

= 2k

TPC 1. Output Voltage Swing vs.
Supply Voltage

50

20

35

25

30

45

40

–SR

+SR

100–25–50 755025

0

TEMPERATURE – C

VS = 15V
R

L

= 2k

SLEW RATE – V/s

VS = 15V
R

L

= 2k

TPC 4. Slew Rate vs. Temperature

120

100

60

0

1k 10k 100k 1M 10M

40

20

80

100

COMMON MODE REJECTION – dB

FREQUENCY – Hz

V

S

= 15V

T

A

= 25C

TPC 7. Common-Mode Rejection
vs. Frequency

1500

0

100

750

250

–25

500

–50

1250

1000

755025

0

OPEN-LOOP GAIN – V/MV

TEMPERATURE – C

VS = 15V
V

O

= 10V

+GAIN

R

L

= 2k

–GAIN
R

L

= 2k

–GAIN
R

L

= 600

+GAIN

R

L

= 600

TPC 2. Open-Loop Gain
vs. Temperature

50

1k

10

–30

10k 100k 1M 10M 100M

20

30

40

–20

–10

0

CLOSED-LOOP GAIN – dB

FREQUENCY – Hz

VS = 15V
T

A

= +25C

A

VCL

= +100

A

VCL

= +10

A

VCL

= +1

TPC 5. Closed-Loop Gain
vs. Frequency

120

10

60

0

100 1k 10k 100k 1M

40

20

80

100

+PSRR

–PSRR

FREQUENCY – Hz

POWER SUPPLY REJECTION – dB

VS = 15V
T

A

= 25C

TPC 8. Power Supply Rejection
vs. Frequency

30

0

1.0

15

5

10

0

25

20

0.80.60.40.2

SLEW RATE – V/s

DIFFERENTIAL INPUT VOLTAGE – V

–SR

+SR

VS = 15V
R

L

= 2k

TPC 3. Slew Rate vs. Differential
Input Voltage

60

100

30

0

1k 10k 100k 1M 10M

20

10

40

50

FREQUENCY – Hz

IMPEDANCE – 

A

VCL

= +1

A

VCL

= +100

A

VCL

= +10

VS = 15V
T

A

= 25C

TPC 6. Closed-Loop Output Imped
ance vs. Frequency

100

1k

20

–60

10k 100k 1M 10M 100M

40

60

80

–40

–20

0

0

45

90

135

180

225

270

OPEN-LOOP G

MIN

– dB

PHASE – Degrees

PHASE

GAIN

FREQUENCY – Hz

V

S

= 15V

R

L

= 2k

T

A

= 25C

0

N

= 58

TPC 9. Open-Loop Gain, Phase
vs. Frequency

REV. A

–5–

Typical Performance Characteristics–OP285

11

7

–50 100

10

8

–25 755025

0

9

40

50

55

60

65

TEMPERATURE – C

GAIN BANDWIDTH PRODUCT – MHz

PHASE MARGIN – Degrees

GBW

M

ø

TPC 10. Gain Bandwidth Product,
Phase Margin vs. Temperature

30

15

0

1k

10k 10M1M100k

10

5

20

25

TA = 25C
V

S

= 15V

A

VCL

= +1

R

L

= 2k

FREQUENCY – Hz

MAXIMUM OUTPUT SWING – V

TPC 13. Maximum Output Swing
vs. Frequency

300

0

100

150

50

–25

100

–50

250

200

755025

0

VS = 15V

TEMPERATURE – C

INPUT BIAS CURRENT – nA

TPC 16. Input Bias Current vs.
Temperature

100

0

500

30

10

100

20

0

60

40

50

70

80

90

400200

300

LOAD CAPACITANCE – pF

OVERSHOOT – %

VS = 15V
R

L

= 2k

V

IN

= 100mV p-p

A = +1
NEGATIVE EDGE

VCL

A = +1
POSITIVE EDGE

VCL

TPC 11. Small-Signal Overshoot vs.|
Load Capacitance

5.0

3.0
25

4.5

3.5

5

4.0

1510

0

TA = +25C

TA = +85C

TA = –40C

SUPPLY CURRENT – mA

SUPPLY VOLTAGE – V

TPC 14. Supply Current vs.
Supply Voltage

FREQUENCY – Hz

10

100 100k1k

5

4

3

2

1

CURRENT NOISE DENSITY – pA/

Hz

VS = 15V
T

A

= 25C

TPC 17. Current Noise Density vs.
Frequency

16

8

0

100 1k 10k

2

4

6

10

12

14

LOAD RESISTANCE – 

MAXIMUM OUTPUT SWING – Volts

TA = 25C
V

S

= 15V

+VOM

–VOM

TPC 12. Maximum Output Voltage
vs. Load Resistance

120

20

100

50

30

–25

40

–50

80

60

70

90

100

110

7525 50

0

TEMPERATURE – C

ABSOLUTE OUTPUT CURRENT – mA

VS = 15V

SOURCE

SINK

TPC 15. Short Circuit Current vs.
Temperature

250

0

10

150

50

1

100

0

200

98765432

UNITS

TC V

OS

– V/ C

–40C TA +85C

402 OP AMPS

TPC 18. tC VOS Distribution