BURR-BROWN OPA2241 User Manual

®

OPA241

OPA4251

OPA241

OPA2241
OPA4241

OPA4241

Single-Supply,

OPERATIONAL AMPLIFIERS

OPA241 Family optimized for +5V supply.
OPA251 Family optimized for ±15V supply.

FEA TURES

●

Micro

POWER: IQ = 25µA

● SINGLE-SUPPLY OPERATION

● RAIL-TO-RAIL OUTPUT (within 50mV)

● WIDE SUPPLY RANGE

Single Supply: +2.7V to +36V
Dual Supply: ±1.35V to ±18V

● LOW OFFSET VOLTAGE: ±250µV max

● HIGH COMMON-MODE REJECTION: 124dB

● HIGH OPEN-LOOP GAIN: 128dB

● SINGLE, DUAL, AND QUAD

APPLICATIONS

● BATTERY OPERATED INSTRUMENTS

● PORTABLE DEVICES

● MEDICAL INSTRUMENTS

● TEST EQUIPMENT

OPA2251

OPA251

OPA2251
OPA4251

Micro

POWER

DESCRIPTION

The OPA241 series and OPA251 series are specifically
designed for battery powered, portable applications. In addi­tion to very low power consumption (25µA), these amplifi­ers feature low offset voltage, rail-to-rail output swing, high
common-mode rejection, and high open-loop gain.

The OPA241 series is optimized for operation at low power
supply voltage while the OPA251 series is optimized for
high power supplies. Both can operate from either single
(+2.7V to +36V) or dual supplies (±1.35V to ±18V). The
input common-mode voltage range extends 200mV below
the negative supply—ideal for single-supply applications.

They are unity-gain stable and can drive large capacitive
loads. Special design considerations assure that these prod­ucts are easy to use. High performance is maintained as the
amplifiers swing to their specified limits. Because the initial
offset voltage (±250µV max) is so low, user adjustment is
usually not required. However, external trim pins are pro­vided for special applications (single versions only).

The OPA241 and OPA251 (single versions) are available
in standard 8-pin DIP and SO-8 surface-mount packages.
The OPA2241 and OPA2251 (dual versions) come in 8-pin
DIP and SO-8 surface-mount packages. The OPA4241 and
OPA4251 (quad versions) are available in 14-pin DIP and
SO-14 surface-mount packages. All are fully specified
from –40°C to +85°C and operate from –55°C to +125°C.

SBOS075

OPA241, OPA251

Offset Trim

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/ • FAXLine: [phone] (US/Canada Only) • Cable: BBRCORP • Telex: 066-6491 • FAX: [phone] • Immediate Product Info: [phone]

© 1997 Burr-Brown Corporation PDS-1406B Printed in U.S.A. October, 1998

–In
+In

1
2
3

V–

4

8-Pin DIP, SO-8

8
7
6
5

NC
V+
Output
Offset Trim

Out A

–In A
+In A

OPA2241, OPA2251

1
2
3

V–

4

A

B

8-Pin DIP, SO-8

1

V+

8

Out B

7

–In B

6

+In B

5

Out A

–In A
+In A

V+
+In B
–In B

Out B

OPA4241, OPA4251

1
2

AD

3
4
5

BC

6
7

14-Pin DIP, SO-14

OPA241, 2241, 4241
OPA251, 2251, 4251

Out D

14

–In D

13

+In D

12

V–

11

+In C

10

–In C

9

Out C

8

®

SPECIFICATIONS: VS = 2.7V to 5V

At TA = +25°C, RL = 100kΩ connected to VS/2, unless otherwise noted.

Boldface limits apply over the specified temperature range, T

PARAMETER CONDITION MIN TYP
OFFSET VOLTAGE

Input Offset Voltage V

T

= –40°C to +85°C ±100 ±400 ±130 µV

A

vs Temperature dV
vs Power Supply PSRR V

T

= –40°C to +85°C VS = 2.7V to 36V 30 ✻ µV/V

A

Channel Separation (dual, quad) 0.3 ✻ µV/V

INPUT BIAS CURRENT

Input Bias Current

T

= –40°C to +85°C –25 nA

A

Input Offset Current I

T

= –40°C to +85°C ±2 nA

A

(2)

OS

/dT TA = –40°C to +85°C ±0.4 ±0.6 µV/°C

OS

I

B

OS

NOISE

Input Voltage Noise, f = 0.1Hz to 10Hz 1 ✻ µVp-p
Input Voltage Noise Density, f = 1kHz e
Current Noise Density, f = 1kHz i

n
n

INPUT VOLTAGE RANGE

Common-Mode Voltage Range V
Common-Mode Rejection Ratio CMRR V

T

= –40°C to +85°C V

A

CM

INPUT IMPEDANCE

Differential 10
Common-Mode 10

OPEN-LOOP GAIN

Open-Loop Voltage Gain A

T

= –40°C to +85°C

A

T

= –40°C to +85°C

A

= 100kΩ, VO = (V–)+100mV to (V+)–100mV

OLRL

RL = 100kΩ, VO = (V–)+100mV to (V+)–100mV

RL = 10kΩ, VO = (V–)+200mV to (V+)–200mV
RL = 10kΩ, VO = (V–)+200mV to (V+)–200mV

FREQUENCY RESPONSE

Gain-Bandwidth Product GBW 35 ✻ kHz
Slew Rate SR V
Overload Recovery Time V

OUTPUT

Voltage Output Swing from Rail

T

= –40°C to +85°C RL = 100kΩ to VS/2, A

A

T

= –40°C to +85°C RL = 10kΩ to VS/2, A

A

Short-Circuit Current I

Single Versions –24/+4 ✻ mA

(3)

V

RL = 100kΩ to VS/2, A

O

R

L

R

SC

Dual, Quad Versions –30/+4 ✻ mA

Capacitive Load Drive C

LOAD

POWER SUPPLY

Specified Voltage Range V
Operating Voltage Range T
Quiescent Current (per amplifier) I

T

= –40°C to +85°C IO = 0 ±36 µA

A

S

Q

TEMPERATURE RANGE

Specified Range –40 +85 ✻✻°C
Operating Range –55 +125 ✻✻°C
Storage Range –55 +125 ✻✻°C
Thermal Resistance

8-Pin DIP 100 ✻ °C/W

θ

JA

SO-8 Surface Mount 150 ✻ °C/W
14-Pin DIP 80 ✻ °C/W
SO-14 Surface Mount 100 ✻ °C/W

✻ Specifications the same as OPA241UA, PA.
NOTES: (1) V

output and power supply rails.

= +5V. (2) The negative sign indicates input bias current flows out of the input terminals. (3) Output voltage swings are measured between the

S

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.

= –40°C to +85°C.

A

OPA241UA, PA OPA251UA, PA
OPA2241UA, PA OPA2251UA, PA
OPA4241UA, PA OPA4251UA, PA

(1)

MAX MIN TYP

(1)

±50 ±250 ±100 µV

= 2.7V to 36V 3 30 ✻✻µV/V

S

–4 –20 ✻ nA

±0.1 ±2 ✻ nA

45 ✻ nV/√Hz
40 ✻ fA/√Hz

= –0.2V to (V+) –0.8V 80 106 ✻ dB

–0.2

CM

= 0V to (V+) –0.8V 80 dB

CM

(V+) –0.8

7

|| 2 ✻ Ω || pF

9

|| 4 ✻ Ω || pF

100 120 ✻ dB
100 dB
100 120 ✻ dB
100 dB

= 5V, G = 1 0.01 ✻ V/µs

S

• G = V

IN

= 100kΩ to VS/2, A

= 10kΩ to VS/2, A

L

S

≥ 70dB 50 ✻ mV

OL

≥ 100dB 75 100 ✻ mV

OL

≥ 100dB 100 mV

OL

≥ 100dB 100 200 ✻ mV

OL

≥ 100dB 200 mV

OL

60 ✻ µs

See Typical Curve ✻

= –40°C to +85°C +2.7 +36 ✻✻V

+2.7 to +5

A

IO = 0 ±25 ±30 ✻ µA

✻ V

MAX UNITS

V

®

OPA241, 2241, 4241
OPA251, 2251, 4251

2

SPECIFICATIONS: VS = ±15V

At TA = +25°C, RL = 100kΩ connected to ground, unless otherwise noted.

Boldface limits apply over the specified temperature range, T

PARAMETER CONDITION MIN TYP MAX MIN TYP MAX UNITS
OFFSET VOLTAGE

Input Offset Voltage V

T

= –40°C to +85°C ±150 ±100 ±300 µV

A

vs Temperature dV
vs Power Supply PSRR V

T

= –40°C to +85°C VS = ±1.35V to ±18V ✻ 30 µV/V

A

Channel Separation (dual, quad) ✻ 0.3 µV/V

INPUT BIAS CURRENT

Input Bias Current

T

= –40°C to +85°C –25 nA

A

Input Offset Current I

T

= –40°C to +85°C ±2 nA

A

(1)

OS

/dT TA = –40°C to +85°C ±0.6 ±0.5 µV/°C

OS

I

B

OS

NOISE

Input Voltage Noise, f = 0.1Hz to 10Hz ✻ 1 µVp-p
Input Voltage Noise Density, f = 1kHz e
Current Noise Density, f = 1kHz i

n
n

INPUT VOLTAGE RANGE

Common-Mode Voltage Range V
Common-Mode Rejection Ratio CMRR V

T

= –40°C to +85°C V

A

CM

INPUT IMPEDANCE

Differential ✻ 10
Common-Mode ✻ 10

OPEN-LOOP GAIN

Open-Loop Voltage Gain A

T

= –40°C to +85°C

A

T

= –40°C to +85°C

A

= 100kΩ, VO = –14.75V to +14.75V

OLRL

RL = 100kΩ, VO = –14.75V to +14.75V

RL = 20kΩ, VO = –14.7V to +14.7V
RL = 20kΩ, VO = –14.7V to +14.7V

FREQUENCY RESPONSE

Gain-Bandwidth Product GBW ✻ 35 kHz
Slew Rate SR G = 1 ✻ 0.01 V/µs
Overload Recovery Time V

OUTPUT

Voltage Output Swing from Rail

T

= –40°C to +85°C RL = 100kΩ, A

A

T

= –40°C to +85°C RL = 20kΩ, A

A

Short-Circuit Current I

Single Versions ✻ –21/+4 mA

(2)

V

O

SC

Dual Versions ✻ –50/+4 mA

Capacitive Load Drive C

LOAD

POWER SUPPLY

Specified Voltage Range V
Operating Voltage Range T
Quiescent Current (per amplifier) I

T

= –40°C to +85°C IO = 0 ±45 µA

A

S

Q

TEMPERATURE RANGE

Specified Range ✻✻–40 +85 °C
Operating Range ✻✻–55 +125 °C
Storage Range ✻✻–55 +125 °C
Thermal Resistance

8-Pin DIP ✻ 100 °C/W

θ

JA

SO-8 Surface Mount ✻ 150 °C/W
14-Pin DIP ✻ 80 °C/W
SO-14 Surface Mount ✻ 100 °C/W

✻ Specifications the same as OPA251UA, PA.
NOTES: (1) The negative sign indicates input bias current flows out of the input terminals. (2) Output voltage swings are measured between the output and

power supply rails.

= –40°C to +85°C.

A

OPA241UA, PA OPA251UA, PA
OPA2241UA, PA OPA2251UA, PA
OPA4241UA, PA OPA4251UA, PA

±100 ±50 ±250 µV

= ±1.35V to ±18V ✻✻ 330µV/V

S

✻ –4 –20 nA

✻ ±0.1 ±2nA

✻ 45 nV/√Hz
✻ 40 fA/√Hz

(V–) –0.2 (V+) –0.8

= –15.2V to 14.2V ✻ 100 124 dB

CM

= –15V to 14.2V 100 dB

CM

7

|| 2 Ω || pF

9

|| 4 Ω || pF

✻ 100 128 dB

100 dB

✻ 100 128 dB

100 dB

• G = V

IN

RL = 100kΩ, A

R

= 100kΩ, A

L

R

= 20kΩ, A

L

S

≥ 70dB ✻ 50 mV

OL

≥ 100dB ✻ 75 250 mV

OL

≥ 100dB 250 mV

OL

≥ 100dB ✻ 100 300 mV

OL

≥ 100dB 300 mV

OL

✻ 60 µs

✻ See Typical Curve

✻ ±15 V

= –40°C to +85°C ✻✻±1.35 ±18 V

A

IO = 0 ✻ ±27 ±38 µA

V

3

OPA251, 2251, 4251

OPA241, 2241, 4241

®

ABSOLUTE MAXIMUM RATINGS

Supply Voltage, V+ to V– .................................................................... 36V

Input Voltage
Output Short Circuit

Operating Temperature .................................................. –55°C to +125°C

Storage Temperature .....................................................–55°C to +125°C

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

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

NOTES: (1) Stresses above these ratings may cause permanent damage.
(2) Input terminals are diode-clamped to the power supply rails. Input signals
that can swing more that 0.5V beyond the supply rails should be current­limited to 5mA or less. (3) One amplifier per package.

(2)

.................................................. (V–) –0.5V to (V+) +0.5V

to Ground

(3)

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

(1)

ELECTROSTATIC
DISCHARGE SENSITIVITY

This integrated circuit can be damaged by ESD. Burr-Brown
recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling
and installation procedures can cause damage.

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 its
published specifications.

PACKAGE/ORDERING INFORMATION

PRODUCT VOLTAGE RANGE PACKAGE NUMBER

SPECIFIED VOLTAGE DRAWING TEMPERATURE

OPA241 SERIES
Single

OPA241PA 2.7V to 5V 2.7V to 36V 8-Pin DIP 006 –40°C to +85°C
OPA241UA 2.7V to 5V 2.7V to 36V SO-8 Surface Mount 182 –40°C to +85°C

Dual

OPA2241PA 2.7V to 5V 2.7V to 36V 8-Pin DIP 006 –40°C to +85°C
OPA2241UA 2.7V to 5V 2.7V to 36V SO-8 Surface Mount 182 –40°C to +85°C

Quad

OPA4241PA 2.7V to 5V 2.7V to 36V 14-Pin DIP 010 –40°C to +85°C
OPA4241UA 2.7V to 5V 2.7V to 36V SO-14 Surface Mount 235 –40°C to +85°C

OPA251 SERIES
Single

OPA251PA ±15V 2.7V to 36V 8-Pin DIP 006 –40°C to +85°C
OPA251UA ±15V 2.7V to 36V SO-8 Surface Mount 182 –40°C to +85°C

Dual

OPA2251PA ±15V 2.7V to 36V 8-Pin DIP 006 –40°C to +85°C
OPA2251UA ±15V 2.7V to 36V SO-8 Surface Mount 182 –40°C to +85°C

Quad

OPA4251PA ±15V 2.7V to 36V 14-Pin DIP 010 –40°C to +85°C
OPA4251UA ±15V 2.7V to 36V SO-14 Surface Mount 235 –40°C to +85°C

NOTE: (1) For detailed drawing and dimension table, please see end of data sheet, or Appendix C of Burr-Brown IC Data Book.

OPERATING PACKAGE SPECIFICATION

(1)

RANGE

®

OPA241, 2241, 4241
OPA251, 2251, 4251

4

TYPICAL PERFORMANCE CURVES

At TA = +25°C, and RL = 100kΩ connected to VS/2 (ground for VS = ±15V), unless otherwise noted.

Curves apply to OPA241 and OPA251 unless specified.

160
140
120
100

80
60
40

Voltage Gain (dB)

20

0

–20

OPEN-LOOP GAIN/PHASE vs FREQUENCY

G

VS = ±15V
V

= +5V

S

0.01 0.1

1 10 100 1k 10k 100k

Frequency (Hz)

180
160
140
120
100

Φ

80

Phase (°)

60
40
20
0

140

120

100

80

60

40

20

Power Supply Rejection Ratio (dB)

0

POWER SUPPLY and COMMON-MODE

REJECTION RATIO vs FREQUENCY

VS = ±15V

VS = ±5V

CMRR

+PSRR

–PSRR

0.1 1 10 100 1k 10k 100k
Frequency (Hz)

140

130

120

110

100

90

Channel Separation (dB)

80

70

30

28

26

24

Quiescent Current (µA)

CHANNEL SEPARATION vs FREQUENCY

Dual and quad devices.
G = 1, all channels.
Quad measured channel
A to D or B to C—other
combinations yield improved
rejection.

10010 1k 10k 100k

QUIESCENT CURRENT vs SUPPLY VOLTAGE

Per Amplifier

Frequency (Hz)

INPUT VOLTAGE AND CURRENT

NOISE SPECTRAL DENSITY vs FREQUENCY

Current Noise

Voltage Noise

0.1 1 10 100 1k 10k
Frequency (Hz)

QUIESCENT CURRENT vs TEMPERATURE

Per Amplifier

VS = ±15V

VS = +5V

Voltage Noise (nV/÷Hz)

Quiescent Current (µA)

1k

100

10

40

35

30

25

20

1k

100

Current Noise (fA/√Hz)

10

22

0 5 10 15 20 25 30 35 40

Total Supply Voltage (V)

15

–75 –50 –25 0 25 50 75 100 125

Temperature (°C)

5

OPA251, 2251, 4251

OPA241, 2241, 4241

®

TYPICAL PERFORMANCE CURVES (CONT)

At TA = +25°C, and RL = 100kΩ connected to VS/2 (ground for VS = ±15V), unless otherwise noted.

Curves apply to OPA241 and OPA251 unless specified.

INPUT BIAS CURRENT vs TEMPERATURE

–6

–4

I

B

–2

I

0

Input Bias Current (nA)

OS

2

–75 –50 –25 0 25 50 75 100 125

Temperature (°C)

SHORT-CIRCUIT CURRENT vs TEMPERATURE

50
45

–I

40
35
30
25
20
15
10

Short-Circuit Current (mA)

SC

Single Versions
Dual, Quad Versions

+ISC, VS = +5V, ±15V (all versions)

5
0

–75 –50 –25 0 25 50 75 100 125

Temperature (°C)

VS = ±15V

VS = +5V

VS = +5V

VS = ±15V

INPUT BIAS CURRENT

–5

–4

–3

–2

Input Bias Current (nA)

–1

0

0 5 10 15 20 25 30

140

120

100

80

60

40

20

Common-Mode Rejection (dB)

0

–75 –50 –25 0 25 50 75 100 125

vs INPUT COMMON-MODE VOLTAGE

I

B

I

OS

Common-Mode Voltage (V)

COMMON-MODE REJECTION vs TEMPERATURE

VS = ±15V

VS = +2.7V, +5V

= (V–) –0.2V to (V+) –0.8V

V

CM

V

= (V–) –0.1V to (V+) –0.8V

CM

V

= (V–) to (V+) –0.8V

CM

Temperature (°C)

OPEN-LOOP GAIN AND POWER

140

130

120

, PSR (dB)

OL

A

110

100

–75 –50 –25 0 25 50 75 100 125

SUPPLY REJECTION vs TEMPERATURE

RL = 20kΩ, 100kΩ

RL = 10kΩ

AOL, VS = ±15V

A

, VS = +5V

OL

Temperature (°C)

®

OPA241, 2241, 4241

PSRR

RL = 100kΩ

OPA251, 2251, 4251

(V+)

(V+) –0.1V

(V+) –0.2V

(V+) –0.3V
(V–) +0.3V

(V–) +0.2V

Output Voltage Swing (V)

(V–) +0.1V

(V–)

0.1 ±1 ±10

6

OUTPUT VOLTAGE SWING vs OUTPUT CURRENT

T = +25°C

T = –55°C

T = +125°C

T = +125°C

T = +25°C, –55°C

Output Current (mA)

TYPICAL PERFORMANCE CURVES (CONT)

MAXIMUM OUTPUT VOLTAGE vs FREQUENCY

100k100 1k 10k

Frequency (Hz)

10

30

25

20

15

10

5

0

Maximum Output Voltage (Vp-p)

Maximum output
voltage without
slew rate-induced
distortion.

VS = 2.7V

VS = +5V

VS = ±15V

At TA = +25°C, and RL = 100kΩ connected to VS/2 (ground for VS = ±15V), unless otherwise noted.

Curves apply to OPA241 and OPA251 unless specified.

140

130

OPEN-LOOP GAIN vs OUTPUT VOLTAGE SWING

VS = ±15V

RL = 20kΩ

RL = 100kΩ

VS = +5V

120

VS = +2.7V

110

100

Open-Loop Gain (dB)

90

80

500 400 300 200 100 0

Output Voltage Swing from Rail (mV)

OPA241 SERIES OFFSET VOLTAGE

30

Typical production
distribution of

25

packaged units.
Singles, duals,

20

and quads included.

15

10

Percent of Amplifiers (%)

5

0

–225

PRODUCTION DISTRIBUTION

–200

–175

–150

–125

–100

RL = 10kΩ

0

–50

–25

255075

–75

Offset Voltage (µV)

VS = +5V

100

125

150

175

200

225

OPA241 SERIES OFFSET VOLTAGE DRIFT

20

= +5V

V

S

18
16
14
12
10

8
6
4

Percent of Amplifiers (%)

2
0

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3

PRODUCTION DISTRIBUTION

Typical production distribution
of packaged units. Singles,
duals, and quads included.

Offset Voltage (µV/°C)

30

25

20

15

10

Percent of Amplifiers (%)

5

0

OPA251 SERIES OFFSET VOLTAGE

PRODUCTION DISTRIBUTION

VS = ±15V

–75

–50

–225

–200

–175

–150

–125

–25

–100

Offset Voltage (µV)

Typical production
distribution of
packaged units.
Singles, duals,
and quads included.

0

255075

100

125

150

175

200

225

OPA251 SERIES OFFSET VOLTAGE DRIFT

18

V

= ±15V

S

16
14
12
10

8
6
4

Percent of Amplifiers (%)

2
0

0

0.1

7

PRODUCTION DISTRIBUTION

Typical production distribution

of packaged units. Singles,
duals, and quads included.

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Offset Voltage Drift (µV/°C)

OPA241, 2241, 4241
OPA251, 2251, 4251

1.0

1.1

1.2

1.3

1.4

1.5

1.6

1.7

1.8

1.9

2.0

®

TYPICAL PERFORMANCE CURVES (CONT)

At TA = +25°C, and RL = 100kΩ connected to VS/2 (ground for VS ±15V), unless otherwise noted.

Curves apply to OPA241 and OPA251 unless specified.

25

VS = +5V

20

Per Amplifier

15

10

5

Percent of Amplifiers (%)

0

21

21.52222.52323.52424.52525.52626.52727.52828.52929.5

SMALL-SIGNAL STEP RESPONSE

V

= +5V, G = +1, RL = 100kΩ, CL = 100pF

S

QUIESCENT CURRENT

PRODUCT DISTRIBUTION

Typical production
distribution of
packaged units.
Singles, duals,
and quads included.

Quiescent Current (µA)

OPA241

QUIESCENT CURRENT

35

VS = ±15V

30

25

20

15

10

Percent of Amplifiers (%)

5

0

30

2223242526272829303132333435363738

V

= +5V, G + 1, RL = 100kΩ, CL = 100pF

S

PRODUCTION DISTRIBUTION

Typical production distribution
of packaged units. Singles,
duals, and quads included.

Per Amplifier

Quiescent Current (µA)

OPA241

LARGE-SIGNAL STEP RESPONSE

50mV/div

200µs/div

SMALL-SIGNAL STEP RESPONSE

V

= ±15V, G = +1, RL = 100kΩ, CL = 500pF

S

50mV/div

OPA251

200µs/div

0.5V/div

200µs/div

OPA251

LARGE-SIGNAL STEP RESPONSE

VS = ±15V, G = +1, RL = 100kΩ, CL = 500pF

2V/div

2ms/div

®

OPA241, 2241, 4241
OPA251, 2251, 4251

8

APPLICATIONS INFORMATION

The OPA241 and OPA251 series are unity-gain stable and
suitable for a wide range of general purpose applications.
Power supply pins should be bypassed with 0.01µF ceramic
capacitors.

OPERATING VOLTAGE

The OPA241 series is laser-trimmed for low offset voltage
and drift at low supply voltage (VS = +5V). The OPA251
series is trimmed for ±15V operation. Both products operate
over the full voltage range (+2.7V to +36V or ±1.35V to
±18V) with some compromises in offset voltage and drift
performance. However, all other parameters have similar
performance. Key parameters are guaranteed over the speci­fied temperature range, –40°C to +85°C. Most behavior
remains unchanged throughout the full operating voltage
range. Parameters which vary significantly with operating
voltage or temperature are shown in typical performance
curves.

Figures 2 and 3 show the regions where the OPA241 series
and OPA251 series have the potential for instability. As
shown, the unity gain configuration with low supplies is the
most susceptible to the effects of capacitive load. With VS =
+5V, G = +1, and I

= 0, operation remains stable with

OUT

load capacitance up to approximately 200pF. Increasing
supply voltage, output current, and/or gain significantly
improves capacitive load drive. For example, increasing the
supplies to ±15V and gain to 10 allows approximately
2700pF to be driven.

One method of improving capacitive load drive in the unity
gain configuration is to insert a resistor inside the feedback
loop as shown in Figure 4. This reduces ringing with large
capacitive loads while maintaining dc accuracy. For ex­ample, with VS = ±1.35V and RS = 5kΩ, the OPA241 series
and OPA251 series perform well with capacitive loads in
excess of 1000pF. Without the series resistor, capacitive
load drive is typically 200pF for these conditions. However,
this method will result in a slight reduction of output voltage
swing.

OFFSET VOLTAGE TRIM

As mentioned previously, offset voltage of the OPA241
series is laser-trimmed at +5V. The OPA251 series is trimmed
at ±15V. Because the initial offset is so low, user adjustment
is usually not required. However, the OPA241 and OPA251
(single op amp versions) provide offset voltage trim connec­tions on pins 1 and 5. Offset voltage can be adjusted by
connecting a potentiometer as shown in Figure 1. This
adjustment should be used only to null the offset of the op
amp, not to adjust system offset or offset produced by the
signal source. Nulling offset could degrade the offset drift
behavior of the op amp. While it is not possible to predict the
exact change in drift, the effect is usually small.

V+

OPA241 and OPA251 (single op amps) only.

0.01µF
Use offset adjust pins only to null

7

offset voltage of op amp—see text.

OPA241

V–

6

5

1
100kΩ

Trim Range: ±2mV
(V–) = 0V for single-supply operation.

0.01µF

2

3

4

FIGURE 1. OPA241 and OPA251 Offset Voltage Trim

Circuit.

CAPACITIVE LOAD AND STABILITY

The OPA241 series and OPA251 series can drive a wide
range of capacitive loads. However, all op amps under
certain conditions may be unstable. Op amp configuration,
gain, and load value are just a few of the factors to consider
when determining stability.

100k

VS = +2.7V

= +5V

V

S

10k

1k

Capacitive Load (pF)

100

–1 –0.1 –0.01 0 0.01 0.1 1

G = –1

Sinking

G = +1

G = 10

Output Current (mA)

Operation above

selected gain curve

not recommended

Sourcing

FIGURE 2. Stability—Capacitive Load versus Output Cur-

rent for Low Supply Voltage.

100k

VS = ±15V

10k

1k

Capacitive Load (pF)

Sinking

100

–1 –0.1 –0.01 0 0.01 0.1 1

G = 10

G = +1

Output Current (mA)

Operation above

selected gain curve

not recommended

G = –1

Sourcing

FIGURE 3. Stability—Capacitive Load versus Output Cur-

rent for ±15V Supplies.

OPA241, 2241, 4241

9

OPA251, 2251, 4251

®

R

S

OPA241

V

IN

5kΩ

V

OUT

C

L

FIGURE 4. Series Resistor in Unity Gain Configuration Improves Capacitive Load Drive.

R

H

10Ω

R

5

383kΩ

V+

A1

OPA241

Out

R

1

38.3kΩ

I

H

R

3

38.3kΩ

High-Side

Current Sense

–In

+In

To Load

= 10 • IH • R

V

O

H

V+ for A

, A

1

2

+

2.7V to ±15V

V– for A1, A

2

R

8

100kΩ

V+

–In

A2

R

10kΩ

6

R

10Ω

I

OPA241

+In

R

7

9.09kΩ

L

Optional for I

(R

L

V–

Current Sense

Cancellation

B

= R6 II R8)

7

Out

NOTE: Low and high-side sensing circuits can be used independently.

FIGURE 5. Low and High-Side Battery Current Sensing.

R

20kΩ

Low-Side

V–

4

R

2

19.1kΩ
R

and R4 divide down the

2

common-mode input to A1.

VO = 10 • IL • R

L

Common-mode range of A2
extends to V– for low-side sensing.

To Load

®

OPA241, 2241, 4241
OPA251, 2251, 4251

10

PACKAGE OPTION ADDENDUM

www.ti.com

PACKAGING INFORMATION

Orderable Device Status

OPA2241PA ACTIVE PDIP P 8 50 Green (RoHS &

OPA2241PAG4 ACTIVE PDIP P 8 50 Green (RoHS &

OPA2241UA ACTIVE SOIC D 8 100 Green(RoHS &

OPA2241UA/2K5 ACTIVE SOIC D 8 2500 Green (RoHS &

OPA2241UA/2K5G4 ACTIVE SOIC D 8 2500 Green (RoHS &

OPA2241UAG4 ACTIVE SOIC D 8 100 Green (RoHS &

OPA2251PA ACTIVE PDIP P 8 50 Green (RoHS &

OPA2251PAG4 ACTIVE PDIP P 8 50 Green (RoHS &

OPA2251UA ACTIVE SOIC D 8 100 Green(RoHS &

OPA2251UA/2K5 ACTIVE SOIC D 8 2500 Green (RoHS &

OPA2251UA/2K5G4 ACTIVE SOIC D 8 2500 Green (RoHS &

OPA2251UAG4 ACTIVE SOIC D 8 100 Green (RoHS &

OPA241PA ACTIVE PDIP P 8 50 Green (RoHS &

OPA241PAG4 ACTIVE PDIP P 8 50 Green (RoHS &

OPA241UA ACTIVE SOIC D 8 100 Green (RoHS &

OPA241UA/2K5 ACTIVE SOIC D 8 2500 Green (RoHS &

OPA241UA/2K5E4 PREVIEW SOIC D 8 2500 TBD Call TI Call TI
OPA241UA/2K5G4 ACTIVE SOIC D 8 2500 Green (RoHS &

OPA241UAE4 PREVIEW SOIC D 8 100 TBD Call TI CallTI
OPA241UAG4 ACTIVE SOIC D 8 100 Green (RoHS &

OPA251PA ACTIVE PDIP P 8 50 Green (RoHS &

OPA251UA ACTIVE SOIC D 8 100 Green (RoHS &

OPA251UA/2K5 ACTIVE SOIC D 8 2500 Green (RoHS &

OPA251UA/2K5G4 ACTIVE SOIC D 8 2500 Green (RoHS &

OPA251UAG4 ACTIVE SOIC D 8 100 Green (RoHS &

OPA4241PA ACTIVE PDIP N 14 25 Green (RoHS & CU NIPDAU N / A for Pkg Type

(1)

Package

Type

Package
Drawing

Pins Package

Qty

Eco Plan

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

no Sb/Br)

(2)

Lead/Ball Finish MSL Peak Temp

CU NIPDAU N / A for Pkg Type

CU NIPDAU N / A for Pkg Type

CU NIPDAU Level-3-260C-168 HR

CU NIPDAU Level-3-260C-168 HR

CU NIPDAU Level-3-260C-168 HR

CU NIPDAU Level-3-260C-168 HR

CU NIPDAU N / A for Pkg Type

CU NIPDAU N / A for Pkg Type

CU NIPDAU Level-3-260C-168 HR

CU NIPDAU Level-3-260C-168 HR

CU NIPDAU Level-3-260C-168 HR

CU NIPDAU Level-3-260C-168 HR

CU NIPDAU N / A for Pkg Type

CU NIPDAU N / A for Pkg Type

CU NIPDAU Level-3-260C-168 HR

CU NIPDAU Level-3-260C-168 HR

CU NIPDAU Level-3-260C-168 HR

CU NIPDAU Level-3-260C-168 HR

CU NIPDAU N / A for Pkg Type

CU NIPDAU Level-3-260C-168 HR

CU NIPDAU Level-3-260C-168 HR

CU NIPDAU Level-3-260C-168 HR

CU NIPDAU Level-3-260C-168 HR

2-Oct-2006

(3)

Addendum-Page 1

PACKAGE OPTION ADDENDUM

www.ti.com

Orderable Device Status

(1)

Package

Type

Package
Drawing

Pins Package

Qty

Eco Plan

(2)

Lead/Ball Finish MSL Peak Temp

2-Oct-2006

(3)

no Sb/Br)

OPA4241PAG4 ACTIVE PDIP N 14 25 Green (RoHS &

CU NIPDAU N / A for Pkg Type

no Sb/Br)

OPA4241UA ACTIVE SOIC D 14 58 Green (RoHS &

CU NIPDAU Level-3-260C-168 HR

no Sb/Br)

OPA4241UA/2K5 ACTIVE SOIC D 14 2500 Green (RoHS &

CU NIPDAU Level-3-260C-168 HR

no Sb/Br)

OPA4241UA/2K5G4 ACTIVE SOIC D 14 2500 Green (RoHS &

CU NIPDAU Level-3-260C-168 HR

no Sb/Br)

OPA4241UAG4 ACTIVE SOIC D 14 58 Green (RoHS &

CU NIPDAU Level-3-260C-168 HR

no Sb/Br)

OPA4251PA ACTIVE PDIP N 14 25 Green (RoHS &

CU NIPDAU N / A for Pkg Type

no Sb/Br)

OPA4251PAG4 ACTIVE PDIP N 14 25 Green (RoHS &

CU NIPDAU N / A for Pkg Type

no Sb/Br)

OPA4251UA ACTIVE SOIC D 14 58 Green (RoHS &

CU NIPDAU Level-3-260C-168 HR

no Sb/Br)

OPA4251UA/2K5 ACTIVE SOIC D 14 2500 Green (RoHS &

CU NIPDAU Level-3-260C-168 HR

no Sb/Br)

OPA4251UA/2K5G4 ACTIVE SOIC D 14 2500 Green (RoHS &

CU NIPDAU Level-3-260C-168 HR

no Sb/Br)

OPA4251UAG4 ACTIVE SOIC D 14 58 Green (RoHS &

CU NIPDAU Level-3-260C-168 HR

no Sb/Br)

(1)

The marketing status values are defined as follows:

ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in

a new design.

PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.

(2)

Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check

http://www.ti.com/productcontent for the latest availability information and additional product content details.

TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements

for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and
package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS
compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame
retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)

(3)

MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder

temperature.

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In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI
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Addendum-Page 2

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