BURR-BROWN INA116 User Manual

INA116

INA116

®

Ultra Low Input Bias Current

INSTRUMENTATION AMPLIFIER

INA1 16

FEATURES

● LOW INPUT BIAS CURRENT: 3fA typ

● BUFFERED GUARD DRIVE PINS

● LOW OFFSET VOLTAGE: 2mV max

● HIGH COMMON-MODE REJECTION:

84dB (G = 10)

● LOW QUIESCENT CURRENT: 1mA

● INPUT OVER-VOLTAGE PROTECTION:

APPLICATIONS

● LABORATORY INSTRUMENTATION

● pH MEASUREMENT

● ION–SPECIFIC PROBES

● LEAKAGE CURRENT MEASUREMENT

Guard

Guard

2

–

3

V

IN

Over-Voltage

4
1

Protection

+1

±40V

DESCRIPTION

The INA116 is a complete monolithic FET-input instru­mentation amplifier with extremely low input bias
current.
yield input bias currents of 3fA at 25°C, and only 25fA
at 85°C. Its 3-op amp topology allows gains to be set
from 1 to 1000 by connecting a single external resistor.

Guard pins adjacent to both input connections can be
used to drive circuit board and input cable guards to
maintain extremely low input bias current.

The INA116 is available in 16-pin plastic DIP and SOL-16
surface-mount packages, specified for the –40°C to +85°C
temperature range.

V+

A

1

25kΩ

®

Difet

inputs and special guarding techniques

13

INA116

50kΩ

60kΩ60kΩ

G = 1 +

R

G

SBOS034

R

G

16

Guard

Guard

®

Difet

; Burr-Brown Corporation

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]

5

+

6

V

IN

Over-Voltage

7

Protection

+1

25kΩ

A

2

8

V–

A

3

60kΩ60kΩ

V

O

11

Ref

9

©1994 Burr-Brown Corporation PDS-1242B Printed in U.S.A. May, 1995

SPECIFICATIONS

AT TA = +25°C, VS = ±15V, RL = 10kΩ, unless otherwise noted.

INA116P, U INA116PA, UA
PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS
INPUT

Offset Voltage, RTI

Initial T
vs Temperature T
vs Power Supply V
Long-Term Stability ±1 ±5/G ✻ µV/mo

Bias Current ±3 ±25 ✻ ±100 fA

vs Temperature See Typical Curve ✻

Offset Current ±1 ±25 ✻ ±100 fA

vs Temperature See Typical Curve ✻

Impedance, Differential >10

Common-Mode >10

Common-Mode Voltage Range
Safe Input Voltage ±40 ✻ V

Common-Mode Rejection V

NOISE

Voltage Noise, RTI G = 1000, R

f = 1kHz 28 ✻ nV/√Hz
f

= 0.1Hz to 10Hz 2 ✻ µVp-p

B

Current Noise

f = 1kHz 0.1 ✻ fA/√Hz

GAIN

Gain Equation 1+(50kΩ/R
Range of Gain 1 1000 ✻✻V/V
Gain Error G = 1 ±0.01 ±0.05 ✻ 0.1 %

Gain vs Temperature

50kΩ Resistance

(1)

(1)(2)

Nonlinearity G = 1 ±0.0005 ±0.005 ✻ ±0.01 % of FSR

GUARD OUTPUTS

Offset Voltage ±15 ±50 ✻✻mV
Output Impedance 650 ✻ Ω
Current Drive +2/–0.05 ✻ mA

OUTPUT

Voltage Positive R

Negative R
Load Capacitance Stability 1000 ✻ pF
Short-Circuit Current +5/–12 ✻ mA

FREQUENCY RESPONSE

Bandwidth, –3dB G = 1 800 ✻ kHz

Slew Rate G = 10 to 200 0.8 ✻ V/µs
Settling Time, 0.01% 10V Step, G = 1 22 ✻ µs

Output Overload Recovery 50% Overdrive 20 ✻ µs

POWER SUPPLY

Voltage Range ±4.5 ±15 ±18 ✻✻✻V
Current V

TEMPERATURE RANGE

Specification –40 85 ✻✻°C
Operating –40 125 ✻✻°C

θ

JA

✻ Specification same as INA116P
NOTE: (1) Guaranteed by wafer test. (2) Temperature coefficient of the “50kΩ” term in the gain equation.

= +25°C ±0.5 ±0.5/G ±2 ±2/G ✻ ±5 ±5/G mV

A

= T

to T

A

MIN

= ±4.5V to ±18V ±10 ±15/G ±50 ±100/G ✻ ±100 ±200/G µV/V

S

= ±11V, ∆RS = 1kΩ

CM

V

= ±5V, G = 1000 86 94 80 ✻ dB

CM

MAX

G = 1 80 89 73 ✻ dB

G = 10 84 92 78 ✻ dB

G = 100 86 94 80 ✻ dB

= 0Ω

S

See Typical Curve ✻

15

/0.2 ✻ Ω/pF

15

(V+)–4 (V+)–2 ✻✻ V
(V–)+4 (V–)+2.4 ✻✻ V

/7 ✻ Ω/pF

) ✻ V/V

G

G = 10 ±0.25 ±0.4 ✻ ±0.5 %

G = 100 ±0.35 ±0.5 ✻ ±0.7 %

G = 1000 ±1.25 ✻ %

G = 1 ±5 ±10 ✻ ±20 ppm/°C

G = 10 ±0.001 ±0.005 ✻ ±0.01 % of FSR

G = 100 ±0.001 ±0.005 ✻ ±0.01 % of FSR

±25 ±100 ✻ ±100 ppm/°C

G = 1000 ±0.005 ✻ % of FSR

= 10kΩ (V+) –1 (V+) –0.7 ✻✻ V

L

= 10kΩ (V–) +0.35 (V–) +0.2 ✻✻ V

L

G = 10 500 ✻ kHz

G = 100 70 ✻ kHz

G = 1000 7 ✻ kHz

G = 10 25 ✻ µs

G = 100 145 ✻ µs

G = 1000 400 ✻ µs

= 0V ±1 ±1.4 ✻✻mA

IN

80 ✻ ° C/W

®

INA116

2

PIN CONFIGURATION

ELECTROSTATIC

Top View DIP

1

R

G

Guard –

Guard –
Guard +

Guard +

2

–

3

V

IN

4
5

+

6

V

IN

7
8

V–

NC: No Internal Connection.

16

R

G

15

NC

14

NC

13

V+

12

NC

11

V

O

10

NC

9

Ref

SOL-16

ABSOLUTE MAXIMUM RATINGS

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

Input Voltage Range .......................................................................... ±40V

Output Short-Circuit (to ground) .............................................. Continuous

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

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

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

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

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 INFORMATION

PRODUCT PACKAGE NUMBER

PACKAGE DRAWING

INA116PA 16-Pin Plastic DIP 180
INA116P 16-Pin Plastic DIP 180
INA116UA SOL-16 Surface-Mount 211
INA116U SOL-16 Surface-Mount 211

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

(1)

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.

3

INA116

®

TYPICAL PERFORMANCE CURVES

At TA = +25°C, VS = ±15V, RL = 10kΩ, unless otherwise noted.

60

G = 1000

50
40

G = 100

30
20

G = 10

Gain (dB)

10

0

G = 1

–10
–20

1k 10k 100k 1M 10M

120

100

80

60

40

Power Supply Rejection (dB)

20

GAIN vs FREQUENCY

Frequency (Hz)

POSITIVE POWER SUPPLY REJECTION

vs FREQUENCY

G = 10V/V

G = 1V/V

G = 1000V/V

G = 100V/V

100

Common-Mode Rejection (dB)

120

100

Power Supply Rejection (dB)

COMMON-MODE REJECTION vs FREQUENCY

90
80
70
60
50
40
30
20
10

0

10 100 1k 10k 100k

Frequency (Hz)

NEGATIVE POWER SUPPLY REJECTION

vs FREQUENCY

80

60

40

20

G = 1000V/V

G = 100V/V

G = 10V/V

G = 1V/V

G = 10 < 100

G = 1

G = 1k

0

1 10 100 1k 10k 100k

Frequency (Hz)

15

10

–5

Input Bias Current (fA)

–10

–15

INPUT BIAS CURRENT vs INPUT VOLTAGE

5

0

–15 –10 –5 0 5 10 15

Input Voltage (V)

®

INA116

0

1 10 100 1k 10k 100k

1000

100

10

Input Bias Current (fA)

1

–75 –50 –25 0 25 50 75 100 125

4

Frequency (Hz)

INPUT BIAS CURRENT vs TEMPERATURE

I

B

Measurement Limit

I

OS