LMC6681 Single/LMC6682 Dual/LMC6684 Quad
Low Voltage, Rail-To-Rail Input and Output CMOS
Amplifier with Powerdown
General Description
The LMC6681/2/4 is a high performance operational ampli-
fier which can operate over a wide range of supply voltages,
with guaranteed specifications at 1.8V, 2.2V, 3V, 5V, and
10V.
The LMC6681/2/4 provides an input common-mode voltage
range that exceeds both supplies. The rail-to-rail output
swing of the amplifier assures maximum dynamic signal
range. This rail-to-rail performance of the amplifier, com-
bined with its high open-loop voltage gain makes it unique
among CMOS rail-to-rail amplifiers. The LMC6681/2/4 is an
excellent choice for circuits where the common-mode volt-
age range is a concern.
The LMC6681/2/4 has a powerdown mode which can be
controlled externally. In this powerdown mode, the supply
current decreases from 700 A per amplifier to less than 1
A per amplifier. The LMC6684 has two powerdown options.
Each of the powerdown pins disables two amplifiers.
The LMC6681/2/4 has been designed specifically to improve
system performance in low voltage applications. The ampli-
fier's 80 fA input current, 0.5 mV offset voltage, and 82 dB
CMRR maintain accuracy in battery-powered systems.
Features
(Typical unless otherwise noted)
n
Guaranteed Specs at 1.8V, 2.2V, 3V, 5V, 10V
n
Rail-to-Rail Input Common-Mode Voltage Range
n
Rail-to-Rail Output Swing
(within 10 mV of supply rail,
@
V
S
=3V and R
L
=10 k
)
n
Powerdown Mode
I
S OFF
1.5 A/Amplifier
(Guaranteed at V
S
= 1.8V, 2.2V, 3V, and 5V)
n
Ultra Low Input Current
80 fA
n
High Voltage Gain (V
S
= 3V, R
L
= 10 k
):
120 dB
n
Unity Gain Bandwidth
1.2 MHz
Applications
n
Battery Operated Circuits
n
Sensor Amplifiers
n
Portable Communication Devices
n
Medical Instrumentation
n
Battery Monitoring Circuits
n
Level Detectors, Sample-and-Hold Circuits
Connection Diagrams
8-Pin DIP/SO
DS012042-1
Top View
14-Pin DIP/SO
DS012042-2
Top View
16-Pin DIP/SO
DS012042-3
Top View
May 1995
LMC6681
Single/LMC6682
Dual/LMC6684
Quad
Low
V
oltage,
Rail-T
o-Rail
Input
and
Output
CMOS
Amplifier
with
Powerdown
1999 National Semiconductor Corporation
DS012042
www.national.com
Ordering Information
Package
Temperature Range
NSC
Transport
Industrial, -40C to +85C
Drawing
Media
8-Pin Molded DIP
LMC6681AIN, LMC6681BIN
N08E
Rails
8-Pin Small Outline
LMC6681AIM, LMC6681BIM
M08A
Rails
LMC6681AIMX, LMC6681B1MX
M08A
Tape and Reel
14-Pin Molded DIP
LMC6682AIN, LMC6682BIN
N14A
Rails
14-Pin Small Outline
LMC6682AIM, LMC6682BIM
M14A
Rails
LMC6682AIMX, LMC6682BIMX
M14A
Tape and Reel
16-Pin Molded DIP
LMC6684AIN, LMC6684BIN
N16A
Rails
16-Pin Small Outline
LMC6684AIM, LMC6684BIM
M16A
Rails
LMC6684AIMX, LMC6684BIMX
M16A
Tape and Reel
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2
Absolute Maximum Ratings
(Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
ESD Tolerance (Note 2)
2 kV
Differential Input Voltage
Supply Voltage
Voltage at Input/Output Pin
(V
+
) +0.3V, (V-) -0.3V
Supply Voltage (V
+
- V-)
12V
Current at Input Pin (Note 11)
5 mA
Current at Output Pin (Note 3)
30 mA
Current at Power Supply Pin
35 mA
Lead Temp. (soldering, 10 sec.)
260C
Storage Temperature Range
-65C to +150C
Junction Temperature (Note 4)
150C
Operating Ratings
(Note 1)
Supply Voltage
1.8V
V
S
10V
Junction Temperature Range
LMC6681AI, LMC6681BI
-40C
T
J
+85C
LMC6682AI, LMC6682BI
-40C
T
J
+85C
LMC6684AI, LMC6684BI
-40C
T
J
+85C
Thermal Resistance (
JA
)
N Package, 8-pin Molded DIP
108C/W
M Package, 8-pin Surface Mount
172C/W
N Package, 14-pin Molded DIP
88C/W
M Package, 14-pin Surface Mount
126C/W
N Package, 16-pin Molded DIP
83C/W
M Package, 16-pin Surface Mount
114C/W
3V DC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for T
J
= 25C, V
+
= 3.0V, V- = 0V, V
CM
= V
O
= V
+
/2, V
PD
= 0.6V and R
L
>
1 M
. Boldface limits apply at the temperature extremes (Note 16).
Symbol
Parameter
Conditions
Typ
(Note 5)
LMC6681AI
LMC6681BI
Units
LMC6682AI
LMC6682BI
LMC6684AI
LMC6684BI
Limit
Limit
(Note 6)
(Note 6)
V
OS
Input Offset Voltage
0.5
1
3
mV
2.5
4.5
max
TCV
OS
Input Offset Voltage
1.5
V/C
Average Drift
I
B
Input Current
(Note 12)
0.08
20
20
pA max
I
OS
Input Offset Current
(Note 12)
0.04
10
10
pA max
R
IN
Input Resistance
>
1
Tera
C
IN
Input Capacitance
3
pF
CMRR
Common Mode
(Note 13)
82
70
65
dB
Rejection Ratio
65
62
min
PSRR
Power Supply
1.5V
V
S
2.5V
82
70
65
dB
Rejection Ratio
V
O
= V
+
/2 = V
CM
65
62
min
V
CM
Input Common Mode
CMRR
>
50 dB
3.23
3.18
3.18
V
Voltage Range
3.00
3.00
min
-0.3
-0.18
-0.18
V
0.00
0.00
max
A
V
Large Signal
Voltage Gain
R
L
= 600
(Notes 7, 12)
70
10
10
V/mV
R
L
= 10 k
(Notes 7, 12)
1000
12
12
V/mV
V
O
Output Swing
R
L
= 600
to V
+
/2
2.87
2.70
2.70
V
2.58
2.58
min
0.15
0.3
0.3
V
0.42
0.42
max
R
L
= 2 k
to V
+
/2
2.95
2.85
2.85
V
2.79
2.79
min
0.05
0.15
0.15
V
0.21
0.21
max
R
L
= 10 k
to V
+
/2
2.99
2.94
2.94
V
2.91
2.91
min
0.01
0.04
0.04
V
0.05
0.05
max
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3
3V DC Electrical Characteristics
(Continued)
Unless otherwise specified, all limits guaranteed for T
J
= 25C, V
+
= 3.0V, V- = 0V, V
CM
= V
O
= V
+
/2, V
PD
= 0.6V and R
L
>
1 M
. Boldface limits apply at the temperature extremes (Note 16).
Symbol
Parameter
Conditions
Typ
(Note 5)
LMC6681AI
LMC6681BI
Units
LMC6682AI
LMC6682BI
LMC6684AI
LMC6684BI
Limit
Limit
(Note 6)
(Note 6)
I
SC
Output Short
Sourcing, V
O
= 0V
20
9.0
9.0
mA
Circuit Current
6.7
6.7
min
Sinking, V
O
= 3V
12
6.0
6.0
mA
4.5
4.5
min
I
S ON
Supply Current
Single, LMC6681
0.7
1.13
1.13
mA
when Powered ON
V
CM
= 1.5V
1.36
1.36
max
Dual, LMC6682
1.4
2.26
2.26
mA
V
CM
= 1.5V
2.75
2.75
max
Quad, LMC6684
2.8
4.52
4.52
mA
V
CM
= 1.5V
5.42
5.42
max
I
S OFF
Supply Current
Single, LMC6681
0.5
1.5
1.5
A
when Powered OFF
V
PD
= 2.3V
2.1
2.1
max
Dual, LMC6682
0.5
1.5
1.5
A
V
PD
= 2.3V
2.1
2.1
max
Quad, LMC6684
1.0
3.0.
3.0
A
V
PD
= 2.3V
4.2
4.2
max
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4
1.8V and 2.2V DC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for T
J
= 25C, V+ = 1.8V and 2.2V, V- = 0V, V
CM
= V
O
= V
+
/2, V
PD
= 0.4V
(
@
2.2V), V
PD
= 0.3V (
@
1.8V) and R
L
>
1 M
. Boldface limits apply at the temperature extremes (Note 16).
LMC6681AI
LMC6681BI
Typ
LMC6682AI
LMC6682BI
Symbol
Parameter
Conditions
(Note 5)
LMC6684AI
LMC6684BI
Units
Limit
Limit
(Note 6)
(Note 6)
V
OS
Input Offset Voltage
V
+
= 1.8V, V
CM
= 1.5V
0.5
3
10
mV max
V
+
= 2.2V, V
CM
= 1.5V
0.5
2
6
mV
3.8
7.8
max
TCV
OS
Input Offset Voltage
V
+
= 2.2V
1.5
V/C
Average Drift
I
B
Input Current
V
+
= 2.2V (Note 12)
0.08
20
20
pA max
I
OS
Input Offset Current
V
+
= 2.2V (Note 12)
0.04
10
10
pA max
CMRR
Common Mode
V
+
= 2.2V (Note 13)
82
60
60
dB min
Rejection Ratio
V
+
= 1.8V (Note 13)
82
50
50
dB min
PSRR
Power Supply
1.1V
V
S
5V,
82
70
65
dB
Rejection Ratio
V
O
= V
+
/2 = V
CM
65
62
min
V
CM
Input Common Mode
V
+
= 2.2V
CMRR
>
40 dB
2.38
2.2
2.2
V min
Voltage Range
-0.15
0.0
0.0
V max
V
+
= 1.8V
CMRR
>
40 dB
1.98
1.8
1.8
V min
-0.10
0.0
0.0
V max
V
O
Output Swing
V
+
= 2.2V
2.15
2.0
2.0
V
R
L
= 2 k
to V
+
/2
1.88
1.88
min
0.05
0.2
0.2
V
0.32
0.32
max
V
+
= 1.8V
1.75
1.6
1.6
V
R
L
= 2 k
to V
+
/2
1.44
1.44
min
0.05
0.2
0.2
V
0.32
0.32
max
I
S ON
Supply Current
Single, LMC6681
0.7
1.1
1.1
mA
when Powered ON
V
CM
= 1.5V
1.32
1.32
max
Dual, LMC6682
1.4
2.2
2.2
mA
V
CM
= 1.5V
2.7
2.7
max
Quad, LMC6684
2.8
4.4
4.4
mA
V
CM
= 1.5V
5.3
5.3
max
I
S OFF
Supply Current
Single, LMC6681
0.5
1.5
1.5
A
when Powered OFF
V
PD
= 1.5V
2.7
2.7
max
Dual, LMC6682
0.5
1.5
1.5
A
V
PD
= 1.5V
2.7
2.7
max
Quad, LMC6684
1.0
3.0
3.0
A
V
PD
= 1.5V
5.4
5.4
max
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