TEXAS INSTRUMENTS OPA129 Technical data

OPA129

OPA129

O

P

A

1

2

9

SBOS026A – JANUARY 1994 – REVISED APRIL 2007

Ultra-Low Bias Current

OPERATIONAL AMPLIFIER

FEATURES

● ULTRA-LOW BIAS CURRENT: 100fA max

● LOW OFFSET: 2mV max

● LOW DRIFT: 10µV/°C max

● HIGH OPEN-LOOP GAIN: 94dB min

● LOW NOISE: 15nV/√Hz at 10kHz

● PLASTIC DIP AND SO PACKAGES

DESCRIPTION

The OPA129 is an ultra-low bias current monolithic
operational amplifier offered in an 8-pin PDIP and
SO-8 package. Using advanced geometry
dielectrically-isolated FET (
amplifier achieves a high performance level.

Difet

fabrication eliminates isolation-junction leakage
current—the main contributor to input bias current with
conventional monolithic FETs. This reduces
input bias current by a factor of 10 to 100. Very low
input bias current can be achieved without resorting to
small-geometry FETs or CMOS designs which can
suffer from much larger offset voltage, voltage noise,
drift, and poor power-supply rejection.

The OPA129 special pinout eliminates leakage current
that occurs with other op amps. Pins 1 and 4 have no
internal connection, allowing circuit board guard traces—
even with the surface-mount package version.

OPA129 is available in 8-pin DIP and SO packages,
specified for operation from –40°C to +85°C.

®

Difet

) inputs, this monolithic

Difet

®

APPLICATIONS

● PHOTODETECTOR PREAMPS

● CHROMATOGRAPHY

● ELECTROMETER AMPLIFIERS

● MASS SPECTROMETERS

● pH PROBE AMPLIFIERS

● ION GAGE MEASUREMENT

–In

2

3

+In

Noise-Free

Cascode

30kΩ 30kΩ

Simplified Circuit

Substrate

8

7

V+

6

Output

5

V–

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

Difet is a registered trademark of Texas Instruments.
All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.

Copyright © 1994–2007, Texas Instruments Incorporated

www.ti.com

SPECIFICATIONS

ELECTRICAL

At VS = ±15V and TA = +25°C, unless otherwise noted. Pin 8 connected to ground.

OPA129PB, UB OPA129P, U

PARAMETER CONDITION MIN TYP MAX MIN TYP MAX UNITS
INPUT BIAS CURRENT

vs Temperature Doubles every 10°C*

INPUT OFFSET CURRENT V
OFFSET VOLTAGE

Input Offset Voltage VCM = 0V ±0.5 ±2 ±1 ±5mV

vs Temperature ±3 ±10 ±5 µV/°C

Supply Rejection V

NOISE

Voltage f = 10Hz 85 * nV/√Hz

Current f = 10kHz 0.1 * fA/√Hz

INPUT IMPEDANCE

Differential 1013 || 1 * Ω || pF
Common-Mode 10

VOLTAGE RANGE

Common-Mode Input Range ±10 ±12 * * V
Common-Mode Rejection V

OPEN-LOOP GAIN, DC

Open-Loop Voltage Gain RL ≥ 2kΩ 94 120 * * dB

FREQUENCY RESPONSE

Unity Gain, Small Signal 1 * MHz
Full Power Response 20Vp-p, R
Slew Rate V
Settling Time: G = –1, R

0.1% 5*µs

0.01% 10 * µs

Overload Recovery, 50% Overdrive

RATED OUTPUT

Voltage Output RL = 2kΩ±12 ±13 * * V
Current Output V
Load Capacitance Stability Gain = +1 1000 * pF
Short-Circuit Current ±35 ±55 * * mA

POWER SUPPLY

Rated Voltage ±15 * V
Voltage Range, Derated Performance ±5 ±18 * * V
Current, Quiescent I

TEMPERATURE

Specification Ambient Temperature –40 +85 * * °C
Operating Ambient Temperature –40 +125 * * °C
Storage –40 +125 * * °C
Thermal Resistance

DIP-8 90 * °C/W
SO-8 100 * °C/W

NOTES: (1) High-speed automated test.

(2) Overload recovery is defined as the time required for the output to return from saturation to linear operation following the removal of a 50% input
overdrive.

(1)

VCM = 0V ±30 ±100 * ±250 fA

= 0V ±30 * fA

CM

= ±5V to ±18V ±3 ±100 * * µV/V

S

f = 100Hz 28 * nV/√Hz

f = 1kHz 17 * nV/√Hz

f = 10kHz 15 * nV/√Hz

f

= 0.1Hz to 10Hz 4 * µV

B

15

|| 2 * Ω || pF

= ±10V 80 118 * * dB

IN

= 2kΩ 47 * kHz

L

= ±10V, RL = 2kΩ 1 2.5 * * V/µs

O

= 2kΩ, 10V Step

L

(2)

G = –15 *µs

= ±12V ±6 ±10 * * mA

O

= 0mA 1.2 1.8 * * mA

O

θ

, Junction-to-Ambient

JA

PP

2

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OPA129

SBOS026A

ABSOLUTE MAXIMUM RATINGS

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

Differential Input Voltage ............................................................ V– to V+

Input Voltage Range .................................................................... V– to V+

Storage Temperature Range ......................................... –40°C to +125°C

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

Output Short Circuit Duration
Junction Temperature (T

NOTE: (1) Short circuit may be to power supply common at +25°C ambient.

(1)

..................................................................

) ............................................................ +150°C

J

Continuous

ELECTROSTATIC
DISCHARGE SENSITIVITY

Any 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.

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.

PACKAGE INFORMATION

PRODUCT PACKAGE-LEAD PACKAGE DESIGNATOR

OPA129P DIP-8 P
OPA129PB DIP-8 P
OPA129U SO-8 D
OPA129UB SO-8 D

NOTE: (1) For the most current package and ordering information, see the
Package Option Addendum at the end of this data sheet, or see the TI website
at www.ti.com.

(1)

CONNECTION DIAGRAM

Top View DIP/SO

1

NC

2

–In

3

+In

4

NC

NC: No internal connection.

OPA

8
7
6
5

Substrate
V+
Output
V–

TYPICAL PERFORMANCE CURVES

At TA = +25°C, +15VDC, unless otherwise noted.

140

120

100

80

60

Voltage Gain (dB)

40

20

0

OPA129

SBOS026A

OPEN-LOOP FREQUENCY RESPONSE

Gain

Phase

Margin

≈90°

1001 1M 10M

1k 10k 100k10

Frequency (Hz)

θ

45

90

135

Pulse Shift (degrees)

180

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140

120

100

80

60

40

Power Supply Rejection (dB)

20

POWER SUPPLY REJECTION vs FREQUENCY

0

1001 1M 10M1k 10k 100k10

+PSRR

–PSRR

Frequency (Hz)

3

TYPICAL PERFORMANCE CURVES (Cont.)

At TA = +25°C, +15VDC, unless otherwise noted.

COMMON-MODE REJECTION

120

110

100

90

80

Common-Mode Rejection (dB)

70

15 1510 10

100pA

10pA

1pA

vs INPUT COMMON-MODE VOLTAGE

505

Common-Mode Voltage (V)

BIAS AND OFFSET CURRENT vs TEMPERATURE

IB and I

140

120

100

80

60

40

Common-Mode Rejection (dB)

20

10

OS

COMMON-MODE REJECTION vs FREQUENCY

0

1001 1M 10M1k 10k 100k10

Frequency (Hz)

BIAS AND OFFSET CURRENT

vs INPUT COMMON-MODE VOLTAGE

1

100

10

Bias and Offset Current (fA)

1

–50 50 125–25 0 25 75 100

Ambient Temperature (°C)

INPUT VOLTAGE NOISE SPECTRAL DENSITY

1k

100

Voltage Density (nV/√Hz)

10

1 10 100 1k 10k 100k

Frequency (Hz)

0.1

Normalized Bias and Offset Current

0.01
–15 –10 –551015

Common-Mode Voltage (V)

30

)

PP

20

10

Output Voltage (V

0

FULL-POWER OUTPUT vs FREQUENCY

10k 100k1k 1M

0

Frequency (Hz)

4

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OPA129

SBOS026A