Burr Brown OPA685N-3K, OPA685U-2K5, OPA685U, OPA685N-250 Datasheet

Ultra-Wideband, Current-Feedback

OPERATIONAL AMPLIFIER With Disable

TM

DESCRIPTION

The OPA685 is a very high bandwidth, current-feed­back op amp that combines exceptional 4200V/µs slew
rate and low input voltage noise to deliver a precision
low cost, high dynamic range Intermediate Frequency
(IF) amplifier. Optimized for high gain operation, the
OPA685 is ideally suited to buffering Surface Acoustic
Wave (SAW) filters in an IF strip or delivering high
output power at low distortion for cable modem up­stream line drivers. Even higher bandwidth at lower
gains gives a 900MHz video line driver for high
resolution workstation graphics.

The OPA685’s low 12.9mA supply current is pre­cisely trimmed at +25°C. This trim, along with a low
temperature drift, guarantees low system power over-

OPA685

®

FEATURES

●

GAIN = +2 BANDWIDTH (900MHz)

●

GAIN = +8 BANDWIDTH (420MHz)

● OUTPUT VOLTAGE SWING: ±3.6V

● ULTRA-HIGH SLEW RATE: 4200V/µs

● 3RD-ORDER INTERCEPT: > 40dBm (f < 50MHz)

● LOW POWER: 129mW

● LOW DISABLED POWER: 3mW

APPLICATIONS

● LOW COST PRECISION IF AMPLIFIER

● CABLE MODEM UPSTREAM DRIVER

● BROADBAND VIDEO LINE DRIVER

● VERY WIDEBAND ADC BUFFER

● PORTABLE INSTRUMENTS

● ACTIVE FILTERS

● ARB WAVEFORM OUTPUT DRIVER

OPA685 RELATED PRODUCTS

SINGLES DUALS

OPA658 OPA2658
OPA681 OPA2681
OPA682 OPA2682

©

1999 Burr-Brown Corporation PDS-1499A Printed in U.S.A. April, 1999

International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: [phone]

Twx: 910-952-1111 • Internet: http://www.burr-brown.com/ • Cable: BBRCORP • Telex: 066-6491 • FAX: [phone] • Immediate Product Info: [phone]

temperature. System power may be further reduced
using the optional disable control pin. Leaving this pin
open, or holding it HIGH, gives normal operation. If
pulled LOW, the OPA685 supply current drops to less
than 320µA. This power-savings feature, along with
exceptional single +5V operation, and ultra-small
SOT23-6 packaging, make the OPA685 ideal for por­table communications requirements.

Low Distortion, 12dB Gain SAW Driver

OPA685

O

P

A

685

For most current data sheet and other product

information, visit www.burr-brown.com

OPA685

SAW
Filter

+5V

–5V

Matching

Network

50Ω

Source

50Ω

50Ω

400Ω

50Ω

50

40

30

20

10

Center Frequency (MHz)

0 50 150 250200100

TWO-TONE, 3rd-ORDER

INTERMODULATION INTERCEPT

Output Intercept (dBm)

2

®

OPA685

SPECIFICATIONS: VS = ±5V

RF = 402Ω, RL = 100Ω, and G = +8, (Figure 1 for AC performance only), unless otherwise noted.

OPA685U, N

TYP GUARANTEED

0°C to –40°C to

MIN/

TEST

PARAMETER CONDITIONS +25°C +25°C

(2)

70°C

(3)

+85°C

(3)

UNITS MAX

LEVEL

(1)

AC PERFORMANCE (Figure 1)

Small-Signal Bandwidth (VO = 0.5Vp-p) G = +1, RF = 523Ω 1200 MHz typ C

G = +2, RF = 511Ω 900 MHz typ C
G = +8, RF = 402Ω 420 360 350 320 MHz min B

G = +16, RF = 249Ω 340 MHz typ C
Bandwidth for 0.1dB Gain Flatness G = +2, VO = 0.5Vp-p, RF =523Ω 350 150 80 70 MHz min B
Peaking at a Gain of +1 RF = 523Ω, VO = 0.5Vp-p 3 4.5 5 6.0 dB max B
Large Signal Bandwidth G = +8, VO = 4Vp-p 350 MHz typ C
Slew Rate G = –8, VO = 4V Step 4200 3000 2500 2200 V/µs min B

G = +8, VO = 4V Step 2900 2400 2400 2100 V/µs min B

Rise/Fall Time G = +8, VO = 0.5V Step 0.7 ns typ C

G = +8, VO = 4V Step 1.0 ns typ C

Settling Time to 0.02% G = +8, VO = 2V Step 4 ns typ C

0.1% G = +8, VO = 2V Step 3 ns typ C

Harmonic Distortion G = +8, f = 10MHz, V

O

= 2Vp-p

2nd Harmonic RL = 100Ω –66 –59 –56 –53 dBc max B

RL ≥ 500Ω –75 –69 –66 –63 dBc max B

3rd Harmonic RL = 100Ω –90 –83 –77 –74 dBc max B

RL ≥ 500Ω –84 –78 –76 –75 dBc max B
Input Voltage Noise f > 1MHz 1.7 1.8 2.2 2.3 nV/√Hz max B
Non-Inverting Input Current Noise f > 1MHz 13 15 15 15 pA/√Hz max B
Inverting Input Current Noise f > 1MHz 19 22 22 22 pA/√Hz max B
Differential Gain G = +2, NTSC, VO = 1.4Vp, RL = 150Ω 0.10 % typ C
Differential Phase G = +2, NTSC, VO = 1.4Vp, RL = 150Ω 0.01 deg typ C

DC PERFORMANCE

(4)

Open-Loop Transimpedance Gain (ZOL)

VO = 0V, RL = 100Ω 42 26 24 23 kΩ min A
Input Offset Voltage VCM = 0V ±1.7 ±3.5 ±5 ±7 mV max A
Average Offset Voltage Drift VCM = 0V +35 +40 µV/°C max B
Non-Inverting Input Bias Current VCM = 0V +56 +90 ±100 ±130 µA max A
Average Non-Inverting Input Bias Current Drift VCM = 0V –530 –570 nA/°C max B
Inverting Input Bias Current VCM = 0V ±10 ±100 ±120 ±150 µA max A
Average Inverting Input Bias Current Drift V

CM

= 0V –500 –560 nA°/C max B

INPUT

Common-Mode Input Range

(5)

(CMIR)

±3.4 ±3.2 ±3.1 ±3.0 V min A

Common-Mode Rejection Ratio (CMRR)

VCM = 0V 54 49 48 48 dB min A
Non-Inverting Input Impedance 87 || 2 kΩ || pF typ C
Inverting Input Resistance (RI)

Open-Loop 19 Ω typ C

OUTPUT

Voltage Output Swing No Load ±4.1

±3.9 ±3.8 ±3.8 V min A

100Ω Load ±3.6 ±3.3 ±3.2 ±3.1 V min A

Current Output, Sourcing VO = 0 +130 +90 +75 +70 mA min A
Current Output, Sinking VO = 0 –90 –60 –50 –45 mA min A
Closed-Loop Output Impedance G = +8, f = 100kHz 0.2 Ω typ C

DISABLE (Disabled Low)

Power Down Supply Current (+V

S

)V

DIS

= 0 –320 µA typ C
Disable Time 100 ns typ C
Enable Time 100 ns typ C
Off Isolation G = +8, 10MHz 70 dB typ C
Output Capacitance in Disable 3 pF typ C
Turn On Glitch G = +2, RL = 150Ω, VIN = 0 ±160 mV typ C
Turn Off Glitch G = +2, RL = 150Ω, VIN = 0 ±20 mV typ C
Enable Voltage 3.3 3.5 3.6 3.7 V min A
Disable Voltage 1.8 1.7 1.6 1.5 V max A
Control Pin Input Bias Current (DIS) V

DIS

= 0 115 160 160 160 µA max A

POWER SUPPLY

Specified Operating Voltage ±5 V typ C
Maximum Operating Voltage Range

±6 ±6 ±6 V max A

Max Quiescent Current VS = ±5V 12.9 13.5 13.5 13.5 mA max A
Min Quiescent Current VS = ±5V 12.9 12.5 11.9 11.2 mA min A
Power Supply Rejection Ratio (–PSRR) Input Referred 55 49 47 46 dB typ A

TEMPERATURE RANGE

Specification: U, N

–40 to +85

°C typ C

Thermal Resistance,

θ

JA

Junction-to-Ambient
U SO-8 125 °C/W typ C
N SOT23-6 150 °C/W typ C

NOTES: (1) Test levels: (A) 100% tested at 25°C. Over temperature limits by characterization and simulation. (B) Limits set by characterization and simulation.
(C) Typical value only for information. (2) Junction temperature = ambient for 25°C guaranteed specifications. (3) Junction temperature = ambient at low temperature
limit: junction temperature = ambient +23°C at high temperature limit for over temperature guaranteed specifications. (4) Current is considered positive out-of-node.
V

CM

is the input common-mode voltage. (5) Tested < 3dB below minimum specified CMRR at ± CMIR limits.

3

®

OPA685

SPECIFICATIONS: VS = +5V

RF = 348Ω, RL = 100Ω to VS/2, and G = +8, (Figure 3 for AC performance only), unless otherwise noted.

OPA685U, N

TYP GUARANTEED

0°C to –40°C to

MIN/

TEST

PARAMETER CONDITIONS +25°C +25°C

(2)

70°C

(3)

+85°C

(3)

UNITS MAX

LEVEL

(1)

AC PERFORMANCE (Figure 3)

Small-Signal Bandwidth (V

O

= 0.5Vp-p) G = +1, RF = 511Ω 600 MHz typ C

G = +2, R

F

= 487Ω 450 MHz min B

G = +8, R

F

= 348Ω 350 240 220 200 MHz typ C

G = +16, R

F

= 162Ω 250 MHz typ C

Bandwidth for 0.1dB Gain Flatness G = +2, V

O

< 0.5Vp-p, RF = 487Ω 140 80 70 60 MHz min B

Peaking at a Gain of +1 R

F

= 511Ω, VO < 0.5Vp-p 0.4 1.0 1.5 1.5 dB max B

Large Signal Bandwidth G = +8, V

O

= 2Vp-p 350 MHz typ C
Slew Rate G = +8, 2V Step 1900 1300 1200 1100 V/µs min B
Rise/Fall Time G = +8, V

O

= 0.5V Step 0.8 ns typ C

G = +8, VO = 2V Step 1.0 ns typ C

Settling Time to 0.02% G = +8, V

O

= 2V Step 9 ns typ C

0.1% G = +8, V

O

= 2V Step 7 ns typ C

Harmonic Distortion G = +8, f = 10MHz, V

O

= 2Vp-p

2nd Harmonic RL = 100Ω to VS/2 –60 –54 –53 –52 dBc max B

RL ≥ 500Ω to VS/2 –68 –60 –59 –58 dBc max B

3rd Harmonic RL = 100Ω to VS/2 –58 –51 –50 –50 dBc max B

RL ≥ 500Ω to VS/2 –60 –55 –54 –54 dBc max B
Input Voltage Noise f > 1MHz 1.7 1.8 2.2 2.2 nV/√Hz max B
Non-Inverting Input Current Noise f > 1MHz 13 15 15 15 pA/√Hz max B
Inverting Input Current Noise f > 1MHz 19 22 22 22 pA/√Hz max B

DC PERFORMANCE

(4)

Open-Loop Transimpedance Gain (ZOL)

VO = VS/2, RL = 100Ω to VS/2 40 25 23 20 kΩ min A

Input Offset Voltage V

CM

= VS/2 ±1 ±3 ±3.5 ±4.0 mV max A

Average Offset Voltage Drift V

CM

= VS/2 12 15 µV/°C max B

Non-Inverting Input Bias Current V

CM

= VS/2 +40 +110 ±120 ±150 µA max A

Average Non-Inverting Input Bias Current Drift V

CM

= VS/2 –550 –650 nA/°C max B

Inverting Input Bias Current V

CM

= VS/2 ±50 ±100 ±120 ±150 µA max A

Average Inverting Input Bias Current Drift V

CM

= VS/2 –550 –650 nA/°C max B

INPUT

Least Positive Input Voltage

(5)

1.7 1.8 1.9 2.0 V max A

Most Positive Input Voltage

(5)

3.3 3.2 3.1 3.0 V min A

Common-Mode Rejection Ratio (CMRR)

VCM = VS/2 54 48 47 47 dB min A
Non-Inverting Input Impedance 87 || 2 kΩ || pF typ C
Inverting Input Resistance (RI)

Open-Loop 23 Ω typ C

OUTPUT

Most Positive Output Voltage No Load 4.1 3.9 3.7 3.5 V min A

R

L

= 100Ω to VS/2 4.0 3.8 3.6 3.4 V min A

Least Positive Output Voltage No Load 0.9 1.1 1.3 1.5 V max A

R

L

= 100Ω to VS/2 1.0 1.2 1.4 1.6 V max A

Current Output, Sourcing V

O

= VS/2 90 62 60 58 mA min A

Current Output, Sinking V

O

= VS/2 –70 –45 –40 –38 mA min A

Closed-Loop Output Impedance G = +2, f = 100kHz 0.3 Ω typ C

DISABLE (Disable Low)

Power Down Supply Current (+V

S

)V

DIS

= 0 –270 µA typ C
Disable Time 150 ns typ C
Enable Time 150 ns typ C
Off Isolation G = +8, 10MHz 70 dB typ C
Output Capacitance in Disable 3 pF typ C
Turn On Glitch G = +2, R

L

= 150Ω, VIN = VS /2 ±160 mV typ C

Turn Off Glitch G = +2, R

L

= 150Ω, VIN = VS /2 ±20 mV typ C
Enable Voltage 3.3 3.5 3.6 3.7 V min A
Disable Voltage 1.8 1.7 1.6 1.5 V max A
Control Pin Input Bias Current (DIS) V

DIS

= 0 100 µA typ C

POWER SUPPLY

Specified Single-Supply Operating Voltage 5 V typ C
Max Single-Supply Operating Voltage 12 12 12 V max A
Max Quiescent Current V

S

= +5V 10.7 11.3 11.3 11.3 mA max A

Min Quiescent Current V

S

= +5V 10.7 9.0 8.3 8.1 mA min A

Power Supply Rejection Ratio (–PSRR) Input Referred 54 51 49 48 dB min A

TEMPERATURE RANGE

Specification: U, N

–40 to +85

°C typ C

Thermal Resistance,

θ

JA

Junction-to-Ambient
U SO-8 125 °C/W typ C
N SOT23-6 150 °C/W typ C

NOTES: (1) Test levels: (A) 100% tested at 25°C. Over temperature limits by characterization and simulation. (B) Limits set by characterization and simulation.
(C) Typical value only for information. (2) Junction temperature = ambient for 25°C guaranteed specifications. (3) Junction temperature = ambient at low temperature
limit: junction temperature = ambient +23°C at high temperature limit for over temperature guaranteed specifications. (4) Current is considered positive out-of-node.
V

CM

is the input common-mode voltage. (5) Tested < 3dB below minimum specified CMRR at ±CMIR limits.

4

®

OPA685

ABSOLUTE MAXIMUM RATINGS

Power Supply .............................................................................. ±6.5VDC

Internal Power Dissipation ................................ See Thermal Information

Differential Input Voltage .................................................................. ±1.2V

Input Voltage Range ............................................................................ ±V

S

Storage Temperature Range: U, N................................–40°C to +125°C

Lead Temperature (soldering, 10s).............................................. +300°C

Junction Temperature (T

J

) ........................................................... +175°C

The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes
no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change
without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant
any BURR-BROWN product for use in life support devices and/or systems.

PACKAGE SPECIFIED
DRAWING TEMPERATURE PACKAGE ORDERING TRANSPORT

PRODUCT PACKAGE NUMBER

(1)

RANGE MARKING NUMBER MEDIA

OPA685U SO-8 Surface Mount 182 –40°C to +85°C OPA685U OPA685U Rails

" " """OPA685U/2K5 Tape and Reel

OPA685N SOT23-6 332 –40°C to +85°C A85 OPA685N/250 Tape and Reel

" " """OPA685N/3K Tape and Reel

NOTES: (1) For detailed drawing and dimension table, please see end of data sheet, or Appendix C of Burr-Brown IC Data Book. (2) Models with a slash (/) are available
only as Tape and Reel in the quantity indicated after the slash (e.g. /3K indicates 3000 devices per reel). Ordering 3000 pieces of the OPA685N/3K will get a single
3000-piece Tape and Reel. For detailed Tape and Reel mechanical information, refer to Appendix B of the Burr-Brown IC Data Book.

PACKAGE/ORDERING INFORMATION

ELECTROSTATIC
DISCHARGE SENSITIVITY

Electrostatic discharge can cause damage ranging from perfor­mance degradation to complete device failure. Burr-Brown Corpo­ration recommends that all integrated circuits be handled and stored
using appropriate ESD protection methods.

ESD damage can range from subtle performance degradation to
complete device failure. Precision integrated circuits may be more
susceptible to damage because very small parametric changes
could cause the device not to meet published specifications.

PIN CONFIGURATIONS

Top View SO-8

NC = No Connection

Top View SOT23-6

1

2

3

4

8

7

6

5

NC

Inverting Input

Non-Inverting Input

–V

S

DIS

+V

S

Output

NC

1

2

3

6

5

4

Output

–V

S

Non-Inverting Input

+V

S

DIS

Inverting Input

123

654

A85

Pin Orientation/Package Marking

5

®

OPA685

TYPICAL PERFORMANCE CURVES: VS = ±5V

G = +8, RF = 402Ω, and RL = 100Ω, unless otherwise noted.

6
3

0
–3
–6
–9

–12
–15
–18
–21
–24

Frequency (100MHz/div)

01GHz500MHz

NON-INVERTING SMALL-SIGNAL

FREQUENCY RESPONSE

Normalized Gain (3dB/div)

G = +16, RF = 249Ω

G = +8, RF = 402Ω

See Figure 1

G = +2, RF = 511Ω

VO = 500mVp-p

G = +4, RF = 475Ω

24
21
18
15
12

9
6
3

0
–3
–6

Frequency (100MHz/div)

0 1GHz500MHz

INVERTING LARGE-SIGNAL

FREQUENCY RESPONSE

Gain (3dB/div)

VO = 4Vp-p

VO = 7Vp-p

G = –8, RF = 442Ω

VO = 1Vp-p

VO = 2Vp-p

See Figure 2

70

60

50

40

30

20

10

0

10

100

G = +8

OPA685

R

S

V

I

C

L

V

O

402Ω

56.2Ω

1kΩ is optional

50Ω

1kΩ

RECOMMENDED RS vs CAPACITIVE LOAD

Capacitive Load (pF)

R

S

(Ω)

21
18
15
12

9

6

3

0

–3

0 250 MHz 500 MHz

Frequency (50MHz/div)

Gain-to-Capacitive Load (3dB/div)

FREQUENCY RESPONSE vs CAPACITIVE LOAD

CL = 10pF

CL = 20pF

CL = 47pF

CL = 100pF

Optimized R

S

24
21
18
15
12

9
6
3

0
–3
–6

Frequency (100MHz/div)

0 1GHz500MHz

NON-INVERTING LARGE-SIGNAL

FREQUENCY RESPONSE

Gain (3dB/div)

VO = 7Vp-p

VO = 2Vp-p

VO = 4Vp-p

G = +8, RF = 402Ω

See Figure 1

VO = 1Vp-p

6
3

0
–3
–6
–9

–12
–15
–18
–21
–23

Frequency (100MHz/div)

01GHz500MHz

INVERTING SMALL-SIGNAL

FREQUENCY RESPONSE

Normalized Gain (3dB/div)

G = –16, RF = 806Ω

G = –2, RF = 499Ω

VO = 500mVp-p

G = –2, RF = 499Ω

G = –4, RF = 475Ω

G = –8, RF = 442Ω

See Figure 2

6

®

OPA685

TYPICAL PERFORMANCE CURVES: VS = ±5V (CONT)

G = +8, RF = 402Ω, and RL = 100Ω, unless otherwise noted. See Figure 1.

–50

–60

–70

–80

–90

–100

10MHz 2nd HARMONIC DISTORTION

vs OUTPUT VOLTAGE

Output Voltage (Vp-p)

0.1 1 10

2nd Harmonic Distortion (dBc)

RL = 500Ω

RL = 100Ω

RL = 200Ω

G = +8V/V

–50

–60

–70

–80

–90

–100

10MHz 3rd HARMONIC DISTORTION

vs OUTPUT VOLTAGE

Output Voltage (Vp-p)

0.1 1 10

3rd Harmonic Distortion (dBc)

RL = 500Ω

RL = 100Ω

RL = 200Ω

G = +8V/V

–50

–60

–70

–80

–90

–100

20MHz 2nd HARMONIC DISTORTION

vs OUTPUT VOLTAGE

Output Voltage (Vp-p)

0.1 1 10

2nd Harmonic Distortion (dBc)

RL = 500Ω

RL = 200Ω

G = +8V/V

RL = 100Ω

–50

–60

–70

–80

–90

–100

20MHz 3rd HARMONIC DISTORTION

vs OUTPUT VOLTAGE

Output Voltage (Vp-p)

0.1 1 10

3rd Harmonic Distortion (dBc)

RL = 500Ω

RL = 100Ω

RL = 200Ω

G = +8V/V

–40

–50

–60

–70

–80

–90

50MHz 2nd HARMONIC DISTORTION

vs OUTPUT VOLTAGE

Output Voltage (Vp-p)

0.1 1 10

2nd Harmonic Distortion (dBc)

RL = 500Ω

RL = 200Ω

RL = 100Ω

G = +8V/V

–40

–50

–60

–70

–80

–90

50MHz 3rd HARMONIC DISTORTION

vs OUTPUT VOLTAGE

Output Voltage (Vp-p)

0.1 1 10

3rd Harmonic Distortion (dBc)

RL = 100Ω

RL = 200Ω

G = +8V/V

RL = 500Ω

7

®

OPA685

TYPICAL PERFORMANCE CURVES: VS = ±5V (CONT)

G = +8, RF = 402Ω, and RL = 100Ω, unless otherwise noted. See Figure 1.

–40

–50

–60

–70

–80

–90

2nd HARMONIC DISTORTION

vs FREQUENCY

Frequency (MHz)

1 10 100

2nd Harmonic Distortion (dBc)

G = +2,

R

F

= 511Ω

G = +4,

R

F

= 475Ω

G = +8

R

F

= 402Ω

G = +16

R

F

= 249Ω

VO = 2Vp-p

R

L

= 100Ω

–40

–50

–60

–70

–80

–90

3rd HARMONIC DISTORTION

vs FREQUENCY

Frequency (MHz)

1 10 100

3rd Harmonic Distortion (dBc)

G = +4

R

F

= 475Ω

G = +16

R

F

= 249Ω

VO = 2Vp-p

R

L

= 100Ω

G = +8

R

F

= 402Ω

G = +2

R

F

= 511Ω

NON-INVERTING LARGE-SIGNAL PULSE RESPONSE

Time (1ns/div)

800mV/div

G = +2

R

F

= 511Ω

V

O

= 4Vp-p

Output

Input

2400

1600

800

0

–800

–1600

–2400

NON-INVERTING SMALL-SIGNAL PULSE RESPONSE

Time (1ns/div)

400mV/div

1200

800

400

0

–400

–800

–1200

Output

Input

G = +2

R

F

= 511Ω

V

O

= 1Vp-p

INVERTING LARGE-SIGNAL PULSE RESPONSE

Time (1ns/div)

800mV/div

Input

2400

1600

800

0

–800

–1600

–2400

Output

See Figure 2

G = –8

R

F

= 442Ω

V

O

= 4Vp-p

INVERTING SMALL-SIGNAL PULSE RESPONSE

Time (1ns/div)

400mV/div

1200

800

400

0

–400

–800

–1200

G = –8

R

F

= 442Ω

V

O

= 1Vp-p

Output

Input

See Figure 2

8

®

OPA685

TYPICAL PERFORMANCE CURVES: VS = ±5V (CONT)

G = +8, RF = 402Ω, and RL = 100Ω, unless otherwise noted.

–15
–20
–25
–30
–35
–40
–45
–50
–55
–60
–65

ISOLATION CHARACTERISTICS vs FREQUENCY

Frequency (Hz)

10M 100M 1G

Isolation (dB)

G = –8 (see Figure 2)

Reverse Isolation (S

12

)

G = +8 (see Figure 1)

Disabled Isolation (S

21

)

G = +8 (see Figure 1)

Reverse Isolation (S

12

)

20

15

10

5

Gain to Matched Load (dB)

6128 9.5 11

NOISE FIGURE vs GAIN

Noise Figure (dB)

Non-Inverting Gain with

50Ω Input Match

Non-Inverting Gain with

1:2 Input Transformer

(see Figure 5)

See Tables I, II, III

RS = 50Ω
T

A

= +25°C

Optimized R

F

Inverting Gain with

50Ω Input Match

100

10

1

INPUT VOLTAGE AND CURRENT NOISE DENSITY

Frequency (Hz)

100 1k 10k 100k 1M 10M

Current Noise (pA/√Hz)

Voltage Noise (nV/√Hz)

Non-Inverting Input Current Noise

Inverting Input Current Noise

13pA/√Hz

19pA/√Hz

Input Voltage Noise

1.7nV/√Hz

–5
–10
–15
–20
–25
–30
–35
–40
–45
–50
–55

INPUT RETURN LOSS vs FREQUENCY (S

11

)

Frequency (Hz)

10M 100M 1G

Return Loss (5dB/div)

G = +8

(see Figure 1)

G = –8

(see Figure 2)

VSWR < 1.2:1

–5
–10
–15
–20
–25
–30
–35
–40
–45
–50
–55

OUTPUT RETURN LOSS vs FREQUENCY (S

22

)

Frequency (Hz)

10M 100M 1G

Return Loss (5dB/div)

G = ±8

Without

Trim Cap

With

Trim Cap

VSWR < 1.2:1

OPA685

50Ω

3.3pF

S

22

Trim Cap

50

40

30

20

10

Center Frequency (MHz)

0 50 150 250200100

TWO-TONE, 3rd-ORDER

INTERMODULATION INTERCEPT

Output Intercept (dBm)

OPA685

P

I

P

O

402Ω

50Ω

50Ω

50Ω

56.2Ω

G = 12dB to matched load.

OPA685

P

I

P

O

402Ω

50Ω

50Ω

50Ω

G = 12dB to matched load.

G = +8

G = –8

9

®

OPA685

TYPICAL PERFORMANCE CURVES: VS = ±5V (CONT)

G = +8, RF = 402Ω, and RL = 100Ω, unless otherwise noted.

0.2

0.18

0.16

0.14

0.12

0.1

0.08

0.06

0.04

0.02

0.

Number of Video Loads

1234

COMPOSITE VIDEO dG/d

φ

dG/d

φ

(%/°)

dG, Positive Video

dφ, Negative Video

dφ, Positive Video

dG, Negative Video

G = +2
R

F

= 511Ω

6.1

6.0

5.9

+1.0
+0.5
0
–0.5
–1.0

0 100 200

Frequency (20MHz/div)

Gain (0.1dB/div)

Phase (0.5°/div)

GAIN FLATNESS AND DEVIATION FROM

LINEAR PHASE vs FREQUENCY

Deviation from Linear Phase

Right Scale

Gain

Left Scale

G = +2
R

L

= 100Ω

R

F

= 523Ω

60
55
50
45
40
35
30
25
20

10

2

10

3

10

4

10

5

10

6

10

7

10

8

CMRR AND PSRR vs FREQUENCY

Frequency (Hz)

Rejection Ratio (dB)

+PSRR

–PSRR

CMRR

95

85

75

65

55

45

35

OPEN-LOOP TRANSIMPEDANCE GAIN/PHASE

Frequency (Hz)

100k 1M 10M 100M 1G 10G

Log Transimpedance Gain (10dBΩ/div)

0

–40

–80

–120

–160

–200

–240

Open-Loop Phase (40°/div)

|ZOL|

∠ Z

OL

15

12

9

6

3

0

150

120

90

60

30

0

–40 –10 20 50 80 110 140

SUPPLY AND OUTPUT CURRENT vs TEMPERATURE

Temperature (C)

Supply Current (mA)

Output Current (mA)

Supply Current

Sourcing Output Current

Sinking Output Current

5
4
3
2
1

0
–1
–2
–3
–4
–5

100
80
60
40
20
0
–20
–40
–60
–80
–100

–40 –20 0 20 40 60 80 100 120 140

TYPICAL DC DRIFT OVER TEMPERATURE

Ambient T emperature (°C)

Input Offset Voltage (mV)

Input Bias Current (µA)

Inverting Input

Bias Current

Non-Inverting Input

Bias Current

V

IO