intersil EL8171, EL8172 DATA SHEET

®

EL8171, EL8172

Data Sheet July 27, 2009

Micropower, Single Supply, Rail-to-Rail
Input-Output Instrumentation Amplifiers

The EL8171 and EL8172 are micropower instrumentation
amplifiers optimized for single supply operation over the
+2.4V to +5.5V range. Inputs and outputs can operate
rail-to-rail. As with all instrumentation amplifiers, a pair of
inputs provide very high common-mode rejection and are
completely independent from a pair of feedback terminals.
The feedback terminals allow zero input to be translated to
any output offset, including ground. A feedback divider
controls the overall gain of the amplifier.

The EL8172 is compensated for a gain of 100 or more, and
the EL8171 is compensated for a gain of 10 or more. The
EL8171 and EL8172 have PMOS input devices that provide
sub-nA input bias currents.

The amplifiers can be operated from one lithium cell or two
Ni-Cd batteries. The EL8171 and EL8172 input range goes
from below ground to slightly above positive rail. The output
stage swings completely to ground (ground sensing) or
positive supply - no pull-up or pull-down resistors are
needed.

Pinout

EL8171, EL8172

(8 LD SOIC)

TOP VIEW

DNC

IN-

IN+

1

2

+

3

V-

4

+

8

FB+

-

-

Σ

7

6

5

V+

VOUT

FB-

FN6293.5

Features

• 95µA maximum supply current

• Maximum input offset voltage

- 300µV (EL8172)

- 1500µV (EL8171)

• 50pA maximum input bias current

• 450kHz -3dB bandwidth (G = 10)

• 170kHz -3dB bandwidth (G = 100)

• Single supply operation

- Input voltage range is rail-to-rail

- Output swings rail-to-rail

- Ground sensing

• Pb-free (RoHS compliant)

Applications

• Battery- or solar-powered systems

• Strain gauges

• Current monitors

• Thermocouple amplifiers

Ordering Information

PART

NUMBER

(Note)

EL8171FSZ* 8171FSZ 8 Ld SOIC MDP0027
EL8172FSZ* 8172FSZ 8 Ld SOIC MDP0027
*Add “-T7” suffix for tape and reel. Please refer to TB347 for details

on reel specifications.
NOTE: These Intersil Pb-free plastic packaged products employ
special Pb-free material sets, molding compounds/die attach
materials, and 100% matte tin plate plus anneal (e3 termination
finish, which is RoHS compliant and compatible with both SnPb and
Pb-free soldering operations). Intersil Pb-free products are MSL
classified at Pb-free peak reflow temperatures that meet or exceed
the Pb-free requirements of IPC/JEDEC J STD-020.

PART

MARKING

PACKAGE

(Pb-free)

PKG.

DWG. #

1

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

1-888-INTERSIL or 1-888-468-3774

| Intersil (and design) is a registered trademark of Intersil Americas Inc.

Copyright © Intersil Americas Inc. 2005-2007, 2009. All Rights Reserved.

All other trademarks mentioned are the property of their respective owners.

EL8171, EL8172

Absolute Maximum Ratings (T

Supply Voltage, V+ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5V

Differential Input Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5mA

Differential Input Voltage (EL8172) . . . . . . . . . . . . . . . . . . . . . . 0.5V

Differential Input Voltage (EL8171) . . . . . . . . . . . . . . . . . . . . . . 1.0V

ESD Rating

Human Body Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3kV

= +25°C) Thermal Information

A

Thermal Resistance θ

8 Ld SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . 122

Output Short-Circuit Duration . . . . . . . . . . . . . . . . . . . . . . .Indefinite

Ambient Operating Temperature . . . . . . . . . . . . . . .-40°C to +125°C

Storage Temperature. . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C

Pb-Free Reflow Profile. . . . . . . . . . . . . . . . . . . . . . . . .see link below

(°C/W)

JA

http://www.intersil.com/pbfree/Pb-FreeReflow.asp

CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and
result in failures not covered by warranty.

IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typical values are for information purposes only. Unless otherwise noted, all tests
are at the specified temperature and are pulsed tests, therefore: TJ = TC = T

Electrical Specifications V

= +5V , V- = GND, VCM = 1/2V+, RL = Open, TA = +25°C, unless otherwise specified. Boldface limits apply

+

over the operating temperature range, -40°C to +125°C.

PARAMETER DESCRIPTION CONDITIONS

A

MIN

(Note 1) TYP

MAX

(Note 1) UNIT

DC SPECIFICATIONS

V

OS

Input Offset Voltage EL8171 -1.5-2±0.47 1.5

mV

2

TCV

OS

Input Offset Voltage Temperature
Coefficient

I

I

V

OS

B

IN

Input Offset Current, ± IN, ± FB -25

Input Bias Current -50

Input Voltage Range Guaranteed by CMRR test 0 5 V

CMRR Common Mode Rejection Ratio V

EL8172 -0.3

-0.7

EL8171 1.5 µV/°C
EL8172 0.14 µV/°C

-500

= 0V to +5V 75 100 dB

CM

-4

±0.07 0.3

0.7

±4 25

500

±10 50

mV

pA
pA

pA

4

nA

PSRR Power Supply Rejection Ratio EL8171, V+ = 2.4V to 5V 75 90 dB

E

G

V

OUT

I

S

V

SUPPLY

I

O+

EL8172, V

Gain Error EL8171, RL = 100kΩ to 2.5V -0.7 ±0.15 0.7 %

EL8172, R

Maximum Voltage Swing Output low, 100kΩ to 2.5V 4 10

Output low, 1kΩ to 2.5V 0.13 0.2

Output high, 100kΩ to 2.5V 4.985

Output high, 1kΩ to GND 4.860

Supply Current 45

Supply Operating Range V+ to V- 2.4 5.5 V
Output Source Current into 10Ω to V+/2 V+ = 5V 23

= 2.4V to 5V 75 100 dB

+

= 100kΩ to 2.5V -1

L

-1.5

±0.2 +1

1.5

10

0.25

4.996 V

4.980

4.87 V

4.750

65 95

38

110

32 mA

%
%

mV
mV

V
V

V

V

µA

19

V

= 2.4V 6

+

4.5

8mA

2

FN6293.5

July 27, 2009

EL8171, EL8172

Electrical Specifications V

PARAMETER DESCRIPTION CONDITIONS

I

O-

Output Sink Current into 10Ω to V+/2 V+ = 5V 19

= +5V , V- = GND, VCM = 1/2V+, RL = Open, TA = +25°C, unless otherwise specified. Boldface limits apply

+

over the operating temperature range, -40°C to +125°C. (Continued)

MIN

(Note 1) TYP

MAX

(Note 1) UNIT

26 mA

15

= 2.4V 5

V

+

4

7mA

AC SPECIFICATIONS

-3dB BW -3dB Bandwidth EL8171 Gain = 10V/V 450 kHz
Gain = 20 210 kHz
Gain = 50 66 kHz
Gain = 100 33 kHz

EL8172 Gain = 100 170 kHz

Gain = 200 70 kHz
Gain = 500 25 kHz
Gain = 1000 12 kHz

e

N

Input Noise Voltage EL8171 f = 0.1Hz to 10Hz 14 µV

EL8172 10 µV

P-P
P-P

Input Noise Voltage Density EL8171 fo = 1kHz 220 nV/√Hz

EL8172 80 nV/√Hz

i

N

CMRR @ 60Hz Input Common Mode Rejection Ratio EL8171 V

PSRR+ @
120Hz

PSRR- @
120Hz

Input Noise Current Density EL8171, fo = 1kHz 0.9 pA/√Hz

Power Supply Rejection Ratio (V

Power Supply Rejection Ratio (V

EL8172, f

EL8172 100 dB

) EL8171 V+, V- = ±2.5V,

+

EL8172 92 dB

) EL8171 V+, V- = ±2.5V,

-

EL8172 92 dB

= 1kHz 0.2 pA/√Hz

o

= 1VPP,

CM

R

= 10kΩ to V

L

CM

85 dB

90 dB

V

SOURCE

R

L

= 1VPP,

= 10kΩ to V

CM

97 dB

V

SOURCE

R

L

= 1VPP,

= 10kΩ to V

CM

TRANSIENT RESPONSE

SR Slew Rate R

= 1kΩ to GND 0.4

L

0.35

0.55 0.7

0.7

V/µs

NOTES:

1. Parameters with MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified. Temperature limits established by characterization
and are not production tested.

3

FN6293.5

July 27, 2009

EL8171, EL8172

Typical Performance Curves V

70

60

50

40

GAIN (dB)

30

20

10

1 10 100 1k 10k 100k 1M

GAIN = 1000
GAIN = 500

GAIN = 200
GAIN = 100
GAIN = 50

GAIN = 20
GAIN = 10

COMMON-MODE INPUT = 1/2V+

FREQUENCY (Hz)

= 5V, V- = 0V,VCM = 2.5V, RL = Open, unless otherwise specified.

+

FIGURE 1. EL8171 FREQUENCY RESPONSE vs CLOSED

LOOP GAIN

25

20

15

10

GAIN (dB)

AV = 10

= 10kΩ

R

L

= 10pF

C

L

5

0

10

= 10

R

F/RG

= 1kΩ

R

F

= 100Ω

R

G

100 10k1k 100k 1M

FREQUENCY (Hz)

V

+

= 2.4V

V+ = 5V

FIGURE 3. EL8171 FREQUENCY RESPONSE vs SUPPLY

VOLTAGE

90

80

70

60

GAIN (dB)

50

40

30

GAIN = 10,000
GAIN = 5,000

GAIN = 2,000
GAIN = 1,000
GAIN = 500

GAIN = 200
GAIN = 100

1 10 100 1k 10k 100k 1M

COMMON-MODE INPUT = 1/2V+

FREQUENCY (Hz)

FIGURE 2. EL8172 FREQUENCY RESPONSE vs CLOSED

LOOP GAIN

45
40
35
30
25
20

GAIN (dB)

15
10

5
0

AV = 100
R

L

C

L

R

F/RG

R

F

R

G

10

= 10kΩ
= 10pF

= 100
= 10kΩ
= 100Ω

100 10k1k 100k 1M

FREQUENCY (Hz)

V

+

V+ = 5V

= 2.4V

FIGURE 4. EL8172 FREQUENCY RESPONSE vs SUPPLY

VOLTAGE

25

470pF

20

220pF

15

GAIN (dB)

AV = 10

= 10kΩ

R

10

= 10pF

C

L

= 10

R

F/RG

= 10kΩ

R

F

= 100Ω

R

G

5

10

100 10k1k 100k 1M

FREQUENCY (Hz)

FIGURE 5. EL8171 FREQUENCY RESPONSE vs C

4

820pF

100pF

LOAD

50

45

40

35

GAIN (dB)

AV = 10

= 10kΩ

R

= 10pF

C

L

30

25

10

= 10

R

F/RG

= 10kΩ

R

F

= 100Ω

R

G

100 10k1k 100k 1M

FREQUENCY (Hz)

820pF

FIGURE 6. EL8172 FREQUENCY RESPONSE vs C

2200pF

1200pF

56pF

LOAD

FN6293.5

July 27, 2009