LMC7221
Tiny CMOS Comparator with Rail-To-Rail Input and Open
Drain Output
General Description
The LM7221 is a micropower CMOS comparator available in
the space saving SOT23-5 package. This makes this com-
parator ideal for space and weight critical designs. The
LMC7221 is also available in the SO-8 package. The
LMC7221 is supplied in two offset voltage grades, 5 mV and
15 mV.
The open drain output can be pulled up with a resistor to a
voltage which can be higher or lower than the supply
voltage -- this makes the part useful for mixed voltage sys-
tems.
For a tiny comparator with a push-pull output, please see the
LMC7211 datasheet.
Features
n
Tiny SOT 23-5 package saves space
n
Package is less than 1.43 mm thick
n
Guaranteed specs at 2.7V, 5V, 15V supplies
n
Typical supply current 7 A at 5V
n
Response time of 4 s at 5V
n
LMC7221 -- open drain output
n
Input common-mode range beyond V- and V+
n
Low input current
Applications
n
Mixed voltage battery powered products
n
Notebooks and PDAs
n
PCMCIA cards
n
Mobile communications
n
Alarm and security circuits
n
Driving low current LEDs
n
Direct sensor interface
Connection Diagrams
Ordering Information
Package
Ordering
NSC Drawing
Package
Transport Media
Information
Number
Marking
8-Pin SO-8
LMC7221AIM
M08A
LMC7221AIM
Rails
LMC7221AIMX
M08A
LMC7221AIM
2.5k Units Tape and Reel
LMC7221BIM
M08A
LMC7221BIM
Rails
LMC7221BIMX
M08A
LMC7221BIM
2.5k Units Tape and Reel
5-Pin SOT 23-5
LMC7221AIM5
MA05A
C01A
1k Units Tape and Reel
LMC7221AIM5X
MA05A
C01A
3k Units Tape and Reel
LMC7221BIM5
MA05A
C01B
1k Units Tape and Reel
LMC7221BIM5X
MA05A
C01B
3k Units Tape and Reel
8Pin SO-8
DS012346-1
Top View
5-Pin SOT23-5
DS012346-2
Top View
September 1999
LMC7221
T
iny
CMOS
Comparator
with
Rail-T
o-Rail
Input
and
Open
Drain
Output
1999 National Semiconductor Corporation
DS012346
www.national.com
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
(V
CC
) +0.3V to (-V
CC
)-0.3V
Voltage at Input
(V
CC
) + 0.3V to (-V
CC
)-0.3V
Voltage at Output Pin
15V
Supply Voltage (V
+
V
-
)
16V
Current at Input Pin
(Note 7)
5 mA
Current at Output Pin
(Notes 3, 8)
30 mA
Current at Power Supply Pin
40 mA
Lead Temperature
(soldering, 10 sec.)
260C
Storage Temperature Range
-65C to +150C
Junction Temperature
(Note 4)
150C
Operating Ratings
(Note 1)
Supply Voltage
2.7
V
CC
15V
Junction Temperature Range
LMC7221AI, LMC7221BI
-40C
T
J
+85C
Thermal Resistance (
JA
)
SO-8 Package,
8-Pin Surface Mount
180C/W
M05A Package,
5-Pin Surface Mount
325C/W
2.7V Electrical Characteristics
Unless otherwise specified, all limits guaranteed for T
J
= 25C, V
+
= 2.7V, V
-
= 0V, V
CM
= V
O
= V+/2. Boldface limits apply
at the temperature extremes
Typ
LMC7221AI
LMC7221BI
Symbol
Parameter
Conditions
(Note 5)
Limit
Limit
Units
(Note 6)
(Note 6)
V
OS
Input Offset Voltage
3
5
15
mV
8
18
max
TCV
OS
Input Offset Voltage
1.0
V/C
Temperature Drift
Input Offset Voltage
(Note 10)
3.3
V/Month
Average Drift
I
B
Input Current
0.04
pA
I
OS
Input Offset Current
0.02
pA
CMRR
Common Mode
0V
V
CM
2.7V
75
dB
Rejection Ratio
PSRR
Power Supply
2.7V
V
+
15V
80
dB
Rejection Ratio
A
V
Voltage Gain
100
dB
CMVR
Input Common-Mode
CMRR
>
55 dB
3.0
2.9
2.9
V
Voltage Range
2.7
2.7
min
CMRR
>
55 dB
-0.3
-0.2
-0.2
V
0.0
0.0
max
V
OL
Output Voltage Low
I
load
= 2.5 mA
0.2
0.3
0.3
V
0.4
0.4
max
I
S
Supply Current
V
OUT
= low
7
12
12
A
14
14
max
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2
5.0V and 15.0V Electrical Characteristics
Unless otherwise specified, all limits guaranteed for T
J
= 25C, V
+
= 5.0V and 15V, V
-
= 0V, V
CM
= V
O
= V
+
/2. Boldface lim-
its apply at the temperature extremes
Typ
LMC7221AI
LMC7221BI
Symbol
Parameter
Conditions
(Note 5)
Limit
Limit
Units
(Note 6)
(Note 6)
V
OS
Input Offset Voltage
3
5
15
mV
8
18
max
TCV
OS
Input Offset Voltage
V
+
= 5V
1.0
V/C
Temperature Drift
V
+
= 15V
4.0
Input Offset Voltage
V
+
= 5V (Note 10)
3.3
V/Month
Average Drift
V
+
= 15V (Note 10)
4.0
I
B
Input Current
0.04
pA
I
OS
Input Offset Current
0.02
pA
CMRR
Common Mode
V+ = 5.0V
75
dB
Rejection Ration
V+ = 15.0V
82
dB
PSRR
Power Supply
5V
V
+
10V
80
dB
Rejection Ratio
A
V
Voltage Gain
100
dB
CMVR
Input Common-Mode
V+ = 5.0V
5.3
5.2
5.2
V
Voltage Range
CMRR
>
55 dB
5.0
5.0
min
V+ = 5.0V
-0.3
-0.2
-0.2
V
CMRR
>
55 dB
0.0
0.0
max
V+ = 15.0V
15.3
15.2
15.2
V
CMRR
>
55 dB
15.0
15.0
min
V+ = 15.0V
-0.3
-0.2
-0.2
V
CMRR
>
55 dB
0.0
0.0
max
V
OL
Output Voltage Low
V+ = 5V
0.2
0.40
0.40
mV
I
load
= 5 mA
0.55
0.55
max
V+ = 15V
0.2
0.40
0.40
mV
I
load
= 5 mA
0.55
0.55
max
I
S
Supply Current
V
OUT
= Low
7
14
14
A
18
18
max
I
SC
Short Circuit Current
Sinking (Note 8)
45
mA
Leakage Characteristics
T
J
= 25C
Typ
LMC7221AI
LMC7221BI
Symbol
Parameter
Conditions
(Note 5)
Limit
Limit
Units
(Note 6)
(Note 6)
I
LEAKAGE
Output Leakage
V+ = 2.7V
Current
V
IN
(+) = 0.5V
0.1
500
500
nA
V
IN
(-) = 0V
V
OUT
= 15V
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3
AC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for T
J
= 25C, V
+
= 5V, V
-
= 0V, V
CM
= V
O
= V
+
/2. Boldface limits apply at
the temperature extreme
Typ
LMC7221AI
LMC7221BI
Symbol
Parameter
Conditions
(Note 5)
Limit
Limit
Units
(Note 6)
(Note 6)
t
rise
Rise Time
f = 10 kHz, C
L
= 50 pF, (Note 9)
0.3
s
Overdrive = 10 mV, 5 k
Pullup
t
fall
Fall Time
f = 10 kHz, C
L
= 50 pF, (Note 9)
0.3
s
Overdrive = 10 mV, 5 k
Pullup
t
PHL
Propagation Delay
f = 10 kHz,
10 mV
10
s
(High to Low)
C
L
= 50 pF,
100 mV
4
(Note 11)
5 k
Pullup
(Note 9)
V+ = 2.7V,
10 mV
10
s
f = 10 kHz,
C
L
= 50 pF,
100 mV
4
5 k
Pullup
(Note 9)
t
PLH
Propagation Delay
f = 10 kHz,
10 mV
6
s
(Low to High)
C
L
= 50 pF,
100 mV
4
(Note 11)
5 k
Pullup
(Note 9)
V+ = 2.7V,
10 mV
7
s
f = 10 kHz,
C
L
= 50 pF,
100 mV
4
5 k
Pullup
(Note 9)
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is in-
tended to be functional, but specific performance is not guaranteed. For guaranteed specifications and the test conditions, see the Electrical Characteristics.
Note 2: Human body model, 1.5 k
in series with 100 pF.
Note 3: Applies to both single-supply and split-supply operation. Continuous short circuit operation at elevated ambient temperature can result in exceeding the
maximum allowed junction temperature of 150C. Output currents in excess of
30 mA may adversely affect reliability.
Note 4: The maximum power dissipation is a function of T
J(max)
,
JA
, and T
A
. The maximum allowable power dissipation at any ambient temperature is
Note 5: P
D
= (T
J(max)
- T
A
)/
JA
. All numbers apply for packages soldered directly into a PC board.
Note 6: Typical values represent the most likely parametric norm.
Note 7: All limits are guaranteed by testing or statistical analysis.
Note 8: Limiting input pin current is only necessary for input voltages which exceed the absolute maximum input voltage rating.
Note 9: Do not short circuit the output to V+ when V+ is greater than 12V or reliability will be adversely affected.
Note 10: C
L
includes the probe and test jig capacitance.
Note 11: Input offset voltage average drift is calculated by dividing the accelerated operating life V
OS
drift by the equivalent operational time. This represents worst
case input conditions and includes the first 30 days of drift.
Note 12: Input step voltage for propagation delay measurement is 2V.
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4
Typical Performance Characteristics
Supply Current vs
Supply Voltage
DS012346-3
Supply Current vs
Temperature while Sinking
DS012346-4
Output Sinking Current vs
Supply Voltage
DS012346-5
Output Sinking Current vs
Output Voltage
@
5V
DS012346-6
Output Sinking Current vs
Output Voltage
@
15V
DS012346-7
Response Time for Various
Input Overdrives -t
PHL
DS012346-8
Response Time vs Various
Input Overdrives -t
PHL
DS012346-9
Response Time vs Various
Input Overdrives -t
PHL
DS012346-10
Input Bias Current vs
Common Mode Voltage
DS012346-11
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5
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