Texas Instruments OPA381, OPA2381 Datasheet

R

l

)

)

SBOS313B − AUGUST 2004 − REVISED NOVEMBER 2004

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments

Precision, Low Power, 18MHz

Transimpedance Amplifier

OPA381

OPA2381

FEATURES

D OVER 250kHz TRANSIMPEDANCE

BANDWIDTH

D DYNAMIC RANGE: 5 Decades
D EXCELLENT LONG-TERM STABILITY
D LOW VOLTAGE NOISE: 10nV/√Hz
D BIAS CURRENT: 3pA
D OFFSET VOLTAGE: 25µV (max)
D OFFSET DRIFT: 0.1µV/°C (max)
D GAIN BANDWIDTH: 18MHz
D QUIESCENT CURRENT: 800µA
D FAST OVERLOAD RECOVERY
D SUPPLY RANGE: 2.7V to 5.5V
D SINGLE AND DUAL VERSIONS
D MicroPACKAGE: DFN-8, MSOP-8

APPLICATIONS

D PRECISION I/V CONVERSION
D PHOTODIODE MONITORING
D OPTICAL AMPLIFIERS
D CAT-SCANNER FRONT-END
D PHOTO LAB EQUIPMENT

F

+5V

7

65pF

4

OPA381

Ω

100k

75pF

Photodiode

C

DIODE

2

Ω

1M

3

6

−

5V

V

OUT

(0V to 4.4V

R

P

(Optiona
Pulldown
Resistor

DESCRIPTION

The OPA381 family of transimpedance amplifie rs provides
18MHz of Gain Bandwidth (GBW), with extremely high
precision, excellent long-ter m stability, and v er y l ow 1 /f n oise.
The OP A381 features a n o f fset v oltage o f 2 5µV ( max), o f fset
drift of 0.1µV/°C (max), and bias c urrent o f 3pA. The O PA381
far exceeds the offset, drift, and noise performance that
conventional JFET op amps provide.

The signal b andwidth of a t ransimpedance a mplifier d epends
largely on the GBW of the amplifier and the parasitic
capacitance of the photodiode, as well as the feedback
resistor. The 18MHz GBW of the OPA381 enables a trans­impedance bandwidth of > 250kHz in mos t configurations.
The OPA381 is ideally suited for fast control loops for power
level measurement on an optical fiber.

As a result o f t he h igh p recision and l ow-noise c haracteristics
of the OPA381, a dynamic range of 5 decades can be
achieved. This capability allows the measurement of signal
currents on the order of 10nA, and up to 1mA in a single I/V
conversion stage. In contrast to logarithmic amplifiers, the
OPA381 provides very wide bandwidth throughout the full
dynamic range. By using an external pulldown resistor to
–5V , t he output voltage r ange c an b e e xtended t o i nclude 0 V.

The OP A381 and OPA2381 are both available in MSOP-8
and DFN-8 (3mm x 3mm) packages. They are specified
from –40°C to +125°C.

OPA381 RELATED DEVICES

PRODUCT FEATURES

OPA380
OPA132 16MHz GBW, Precision FET Op Amp ±15V

OPA300 150MHz GBW, Low-Noise, 2.7V to 5.5V Supply
OPA335 10µV VOS, Zero-Drift, 2.5V to 5V Supply
OPA350 500µV VOS, 38MHz, 2.5V to 5V Supply
OPA354 100MHz GBW CMOS, RRIO, 2.5V to 5V Supply
OPA355 200MHz GBW CMOS, 2.5V to 5V Supply
OPA656/7 230MHz, Precision FET, ±5V

90MHz GBW, 2.7V to 5.5V Supply
Transimpedance Amplifier

semiconductor products and disclaimers thereto appears at the end of this data sheet.

All trademarks are the property of their respective owners.

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Copyright  2004, Texas Instruments Incorporated

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OPA381

MSOP-8

DGK

−40°C to +125°C

A64

OPA381

DFN-8

DRB

−40°C to +125°C

A65

OPA2381

MSOP-8

DGK

−40°C to +125°C

A62

OPA2381

DFN-8

DRB

−40°C to +125°C

A63

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SBOS313B − AUGUST 2004 − REVISED NOVEMBER 2004

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ABSOLUTE MAXIMUM RATINGS

(1)

Voltage Supply +7V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Signal Input Terminals

(2)

,Voltage (V−) −0.5V to (V+) + 0.5V. . . . .

Current ±10mA. . . . . . . . . . . . . . . . . . . . .

Short-Circuit Current

(3)

Continuous. . . . . . . . . . . . . . . . . . . . . . . .

ELECTROSTATIC DISCHARGE SENSITIVITY

This integrated circuit can be damaged by ESD. Texas
Instruments recommends that all integrated circuits be
handled with appropriate precautions. Failure to observe

proper handling and installation procedures can cause damage.

Operating Temperature Range −40°C to +125°C. . . . . . . . . . . . . . .

Storage Temperature Range −65°C to +150°C. . . . . . . . . . . . . . . . .

Junction Temperature +150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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

OPA381 ESD Rating (Human Body Model) 2000V. . . . . . . . . . . . . . .

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

OPA2381 ESD Rating (Human Body Model) 1500V. . . . . . . . . . . . . .

(1)

Stresses above these ratings may cause permanent damage.
Exposure to absolute maximum conditions for extended periods
may degrade device reliability. These are stress ratings only , an d
functional operation of the device at these or any other conditions
beyond those specified is not implied.

(2)

Input terminals are diode clamped to the power-supply rails. Input
signals that can swing more than 0.5V beyond the supply rails
should be current limited to 10mA or less.

(3)

Short-circuit to ground; one amplifier per package.

PACKAGE/ORDERING INFORMATION

PRODUCT PACKAGE-LEAD

PACKAGE

DESIGNATOR

(1)

SPECIFIED

TEMPERATURE

RANGE

PACKAGE

MARKING

ORDERING

NUMBER

OPA381AIDGKT Tape and Reel, 250
OPA381AIDGKR Tape and Reel, 2500
OPA381AIDRBT T ape and Reel, 250

OPA381AIDRBR T ape and Reel, 3000
OPA2381AIDGKT Tape and Reel, 250
OPA2381AIDGKR Tape and Reel, 2500
OPA2381AIDRBT Tape and Reel, 250
OPA2381AIDRBR T ape and Reel, 3000

(1)

For the most current package and ordering information, see the Package Option Addendum located at the end of this data sheet.

TRANSPORT

MEDIA, QUANTITY

PIN ASSIGNMENTS

Top View

(1)

1

NC

−

In

2
3

+In

−

V

4

Out A

1

−

In A

2

+In A

3

−

V

4

2

OPA381

MSOP−8

OPA2381

MSOP−8

OPA381

(1)

NC

8

V+

7

Out

6

(1)

NC

5

NOTE: (1) NC indicates no internal connection.

V+

8

Out B

7

−

In B

6

+In B

5

NC

−

+In

V

Out A

−

In A

+In A

V

(1)

1

Exposed

Thermal

In

2

Die Pad

3

on

Underside

−

4

DFN−8

OPA2381

1

Exposed

Thermal

2

Die Pad

3

on

Underside

−

4

DFN−8

(1)

NC

8

V+

7

Out

6

(1)

NC

5

V+

8

OutB

7

−

In B

6

+In B

5

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SBOS313B − AUGUST 2004 − REVISED NOVEMBER 2004

ELECTRICAL CHARACTERISTICS: VS = +2.7V to +5.5V

Boldface limits apply over the temperature range, TA = −40°C to +125°C.

All specifications at TA = +25°C, RL = 10kΩ connected to VS/2, and V

PARAMETER CONDITION

OFFSET VOLTAGE

Input Offset Voltage V

Drift dVOS/dT 0.03 0.1 µV/°C

vs Power Supply PSRR VS = +2.7V to +5.5V, VCM = 0V 3.5 20 µV/V

Over Temperature VS = +2.7V to +5.5V, VCM = 0V 20 µV/V

Long-Term Stability

Channel Separation, dc 1 µV/V

INPUT BIAS CURRENT

Input Bias Current I

Over Temperature See Typical Characteristics

Input Offset Current I

NOISE

Input Voltage Noise, f = 0.1Hz to 10Hz e
Input Voltage Noise Density, f = 10kHz e
Input Voltage Noise Density, f > 1MHz e
Input Current Noise Density, f = 10kHz i

INPUT VOLTAGE RANGE

Common-Mode Voltage Range V

Common-Mode Rejection Ratio CMRR VS = +5V, (V−) < VCM < (V+) − 1.8V 95 110 dB
INPUT IMPEDANCE

Differential Capacitance 1 pF
Common-Mode Resistance and Capacitance 1013|| 2.5 Ω || pF

OPEN-LOOP GAIN
Open-Loop Voltage Gain A

FREQUENCY RESPONSE

Gain-Bandwidth Product GBW 18 MHz
Slew Rate SR G = +1 12 V/µs
Settling Time, 0.0015%
Settling Time, 0.003%
Overload Recovery Time

OUTPUT
Voltage Output Swing from Positive Rail RL = 10kΩ 400 600 mV
Voltage Output Swing from Negativ e Ra il RL = 10kΩ 30 50 mV
Voltage Output Swing from Positive Rail RP = 10kΩ to −5V
Voltage Output Swing from Negativ e Ra il RP = 10kΩ to −5V

Output Current I
Short-Circuit Current I
Capacitive Load Drive C
Open-Loop Output Impedance R

POWER SUPPL Y

Specified Voltage Range V
Quiescent Current (per amplifier) I

Over Temperature 1.1 mA

TEMPERATURE RANGE

Specified and Operating Range −40 +125 °C
Storage Range −65 +150 °C
Thermal Resistance q

MSOP-8 150 °C/W
DFN-8 65 °C/W

(1)

High temperature operating life characterization of zero-drift op amps applying the techniques used in the OPA381 have repeatedly demonstrated randomly
distributed variation approximately equal to measurement repeatability of 1µV. This consistency gives confidence in the stability and repeatability of these zero­drift techniques.

(2)

Tested with output connected only to RP, a pulldown resistor connected between V

Output Swing to Negative Rail.

(3)

Transimpedance frequency of 250kHz.

(4)

Time required to return to linear operation.

(5)

From positive rail.

(1)

(3)

(3)

(4), (5)

OS

OS

CM

OL

OUT

SC

LOAD

B

n
n
n
n

0.05V < VO < (V+) − 0.6V, VCM = VS/2, VS = 5V 110 135 dB

0V < V

< (V+) − 0.6V, V

O

VS = +5V, 4V Step, G = +1, OPA381 7 µs

VS = +5V, 4V Step, G = +1, OPA2381 7 µs

O

S

Q

JA

= VS/2, unless otherwise noted.

OUT

MIN TYP MAX

VS = +5V, VCM = 0V 7 25 µV

VCM = VS/2 3 ±50 pA

VCM = VS/2 6 ±100 pA

VS = +5V, VCM = 0V 3 µV
VS = +5V, VCM = 0V 70 nV/√Hz
VS = +5V, VCM = 0V 10 nV/√Hz
VS = +5V, VCM = 0V 20 fA/√Hz

V− (V+) − 1.8V V

= 0V, R

CM

VIN • G = > V

F = 1MHz, IO = 0 250 Ω

= 10kΩ to −5V

P

S

(2)
(2)

IO = 0A 0.8 1 mA

and −5V , as shown in Figure 3. See also Applications section, Achieving

OUT

(2)

, VS = 5V 106 135 dB

2.7 5.5 V

OPA381

UNITS

See Note (1)

200 ns

400 600 mV

−20 0 mV

10 mA
20 mA

See Typical Characteristics

PP

3

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SBOS313B − AUGUST 2004 − REVISED NOVEMBER 2004

TYPICAL CHARACTERISTICS: VS = +2.7V to +5.5V

All specifications at TA = +25°C, RL = 10kΩ connected to VS/2, and V

= VS/2, unless otherwise noted.

OUT

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140

OPEN−LOOPGAIN AND PHASE vsFREQUENCY

120

Phase

100

80
60
40
20

Open−Loop Gain(dB)

Gain

0

−

20

10 100k 1M100 1k 10k 100M10M

Frequency (Hz)

PHASE MARGIN vs LOAD CAPACITANCE

90
80
70

)

_

60
50
40

Phase Margin(

30

RS=50

Ω

RS=0

20
10

0 100 200 300 400 500 600 700 900800 1000

Load Capacitance (pF)

C

L

RS=100

Ω

100pF

POWER−SUPPLY REJECTION RATIO AND
200
150
100

50
0

−

−

−

−

50
100
150
200

140
120
100

)

_

Phase (

PSRR, CMRR (dB)

−

−

−

COMMON−MODE REJECTION vs FREQUENCY

80

PSRR

60
40
20

0

CMRR

20
40
60

10 100k 1M100 1k 10k 100M10M

Frequency (Hz)

QUIESCENT CURRENT vs TEMPERATURE

Ω

1.00

0.90

0.85

Ω

50k

R

S

C

L

0.80

5.5V

0.75

0.70

0.65

2.7V

Quiescent Current (mA)

0.60

0.55

0.50

−

−

40 100 125

25 0 25 50 75

Temperature (_C)

1.00

QUIESCENT CURRENT vs SUPPLY VOLTAGE

1000

INPUT BIAS CURRENT vs TEMPERATURE

0.90

0.85

0.80

100

0.75

0.70

0.65

Quiescent Current (mA)

0.60

10

Input BiasCurrent (pA)

0.55

0.50

2.73.13.53.94.34.75.15.5
Supply Voltage (V)

1

−

−

40 100 125

25 0 25 50 75

Temperature (_C)

4

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OUTPUT VOLTAGE SWING vs OUTPUT CURRENT

OFFSETVOLTAGE DRIFT

GAIN BANDWIDTH vs POWER SUPPLY VOLTAGE

SBOS313B − AUGUST 2004 − REVISED NOVEMBER 2004

TYPICAL CHARACTERISTICS: VS = +2.7V to +5.5V (continued)

All specifications at TA = +25°C, RL = 10kΩ connected to VS/2, and V

= VS/2, unless otherwise noted.

OUT

"#$

%"#$

Input BiasCurrent (pA)

(V+)−0.35
(V+)−0.70

(V+)−1.05
(V+)−1.40

(V−) + 1.40

Output Swing (V)

(V−) + 1.05
(V−) + 0.70
(V−) + 0.35

INPUT BIAS CURRENT

50
40
30
20
10

0

−

10

−

20

−

30

−

40

−

50

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

(V+)

(V−)

vs COMMON−MODE VOLTAGE

−

I

B

+

I

B

Common−Mode Voltage (V)

(VS=2.7V)

+125_C

+25_C

5 101520250

Output Current (mA)

−40_

C

(V+)−1

(V+)−2

(V−)+2

OutputSwing (V)

(V−)+1

OUTPUT VOLTAGE SWING vs OUTPUT CURRENT

(V+)

(V−)

Population

0.10−0.09−0.08−0.07−0.06−0.05−0.04−0.03−0.02−0.01

−

=5.5V)

(V

S

+125_C

5101520250

Output Current (mA)

PRODUCTION DISTRIBUTION

0.00

0.01

0.02

0.03

Offset Voltage Drift (µV/_C)

0.04

+25°C

−40_

0.05

0.06

C

0.07

0.08

0.09

0.10

OFFSET VOLTAGE PRODUCTION DISTRIBUTION

Population

25.00−20.00−15.00−10.00

−

5.00

0.00

−

Offset Voltage (µV)

20
19
18
17
16
15
14

GainBandwidth (MHz)

13
12

5.00

10.00

15.00

20.00

25.00

3.5 4.03.0 4.5 5.0 5.52.5

Power Supply Voltage (V)

5

"#$
%"#$

SBOS313B − AUGUST 2004 − REVISED NOVEMBER 2004

TYPICAL CHARACTERISTICS: VS = +2.7V to +5.5V (continued)

All specifications at TA = +25°C, RL = 10kΩ connected to VS/2, and V

= VS/2, unless otherwise noted.

OUT

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Circuit for Transimpedance Amplifier Characteristic curves on this page.

C

F

R

F

C

STRAY

OPA381

C

DIODE

TRANSIMPEDANCE AMPCHARACTERISTIC
150
140
130
120
110

RF=10MΩ

RF=1M

Ω

CF=1pF

C

DIODE

= 50pF

100

90
80
70
60

RF= 100kΩ

RF=10kΩ

CF= 3pF

CF=8pF

50
40
30

Transimpedance Gain (V/A in dB)

20

C

(parasitic) = 0.2pF

STRAY

10

100

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

Frequency (Hz)

150
140
130
120

110

RF=10MΩ

RF=1M

Ω

CF= 0.5pF

CF=1pF

C

DIODE

100

TRANSIMPEDANCE AMPCHARACTERISTIC

90
80
70
60

RF= 100kΩ

RF=10kΩ

CF= 4pF

CF=12pF

50
40
30

Transimpedance Gain (V/A in dB)

20

C

(parasitic) = 0.2pF

STRAY

10

100

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

Frequency (Hz)

TRANSIMPEDANCE AMPCHARACTERISTIC
150
140
130

RF= 10M

Ω

C

DIODE

120

110

100

90
80
70
60

RF=100k

RF= 10k

Ω

Ω

CF=0.5pF

CF=2pF

CF=5pF

Ω

RF=1M

50
40
30

Transimpedance Gain (V/A in dB)

C

(parasitic) = 0.2pF

STRAY

20
10

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

Frequency (Hz)

= 100pF

= 20pF

150
140
130

RF= 10M

Ω

C

DIODE

120

TRANSIMPEDANCE AMPCHARACTERISTIC

110

100

90
80
70
60
50

RF=100k

RF= 10k

Ω

Ω

CF=0.5pF

CF=2pF

CF=4pF

Ω

RF=1M

40
30

Transimpedance Gain (V/A in dB)

C

(parasitic) = 0.2pF

STRAY

20
10

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

Frequency (Hz)

= 10pF

150
140
130
120

110

100

90
80
70
60
50
40
30

Transimpedance Gain (V/A in dB)

20
10

TRANSIMPEDANCE AMP CHARACTERISTIC

C

=1pF

DIODE

Ω

RF= 10M

Ω

RF=1M

RF=100k

RF= 10k

C

STRAY

Ω

Ω

(parasitic) = 0.2pF

CF= 0.5pF

CF= 2pF

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

Frequency (Hz)

6

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OVERLOAD RECOVERY

SBOS313B − AUGUST 2004 − REVISED NOVEMBER 2004

TYPICAL CHARACTERISTICS: VS = +2.7V to +5.5V (continued)

All specifications at TA = +25°C, and RL = 10kΩ connected to VS/2, unless otherwise noted.

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SMALL−SIGNAL STEP RESPONSE

(with or without pull−down)

LARGE−SIGNAL STEP RESPONSE

(with pull−down)

200kHz (CF= 16pF)

1MHz

= 3pF)

(C

F

C

F

Ω

50mV/div

50k

OPA381

Ω

10k

V

P

VP=0Vor−5V

1V/div

Time (100ns/div)

LARGE−SIGNAL STEP RESPONSE

(withoutpull−down)

200kHz

=16pF)

(C

=3pF)

F

C

F

Ω

50k

OPA381

Ω

10k

1MHz
(C

F

1V/div

6

V

OUT

4

(V/div)I

2

OUT

V

0

0.8

(mA/div)

0

IN

Nonlinear

Operation

OPA381

OPA2381

I

IN

0 100 200 300 400 500 600 700 800 900 1000

Time(100ns/div)

3pF

Ω

50k

OPA381

Time (100ns/div)

Linear
Operation

Time (ns)

−5V

10kΩ

I

IN

40pF

20kΩ

250µA

OPA381

10kΩ

V

VP=0Vor−5V

P

1000

INPUT VOLTAGE NOISE SPECTRAL DENSITY

(Hz)

√

100

10

Input Voltage Noise(nV/

1

10 100 100k 1M10k1k 10M

Frequency (Hz)

160
140

CHANNEL SEPARATION vs INPUT FREQUENCY

OPA2381

120
100

80
60
40
20

Channel Separation (dB)

0

−

20

−

40

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

Input Frequency (Hz)

7