LM2903EP
Low Power Low Offset Voltage Dual Comparators
General Description
The LM2903EP consists of two independent precision volt-
age comparators with an offset voltage specification as low
as 2.0 mV max for two comparators which were designed
specifically to operate from a single power supply over a
wide range of voltages. Operation from split power supplies
is also possible and the low power supply current drain is
independent of the magnitude of the power supply voltage.
This comparator also has a unique characteristic in that the
input common-mode voltage range includes ground, even
though operated from a single power supply voltage.
Application areas include limit comparators, simple analog to
digital converters; pulse, squarewave and time delay gen-
erators; wide range VCO; MOS clock timers; multivibrators
and high voltage digital logic gates. The LM2903EP was
designed to directly interface with TTL and CMOS. When
operated from both plus and minus power supplies, the
LM2903EP will directly interface with MOS logic where their
low power drain is a distinct advantage over standard com-
parators.
ENHANCED PLASTIC
•Extended Temperature Performance of −40˚C to +85˚C
•Baseline Control - Single Fab & Assembly Site
•Process Change Notification (PCN)
•Qualification & Reliability Data
•Solder (PbSn) Lead Finish is standard
•Enhanced Diminishing Manufacturing Sources (DMS)
Support
Advantages
nHigh precision comparators
nReduced V
OS
drift over temperature
nEliminates need for dual supplies
nAllows sensing near ground
nCompatible with all forms of logic
nPower drain suitable for battery operation
Features
nWide supply
— Voltage range: 2.0V to 36V
— Single or dual supplies: ±1.0V to ±18V
nVery low supply current drain (0.4 mA) — independent
of supply voltage
nLow input biasing current: 25 nA
nLow input offset current: ±5nA
nMaximum offset voltage: ±3mV
nInput common-mode voltage range includes ground
nDifferential input voltage range equal to the power
supply voltage
nLow output saturation voltage,: 250 mV at 4 mA
nOutput voltage compatible with TTL, DTL, ECL, MOS
and CMOS logic systems
Applications
nSelected Military Applications
nSelected Avionics Applications
Ordering Information
PART NUMBER VID PART NUMBER NS PACKAGE NUMBER (Note 3)
LM2903MEP V62/04745-01 M08A
(Notes 1, 2) TBD TBD
Note 1: For the following (Enhanced Plastic) version, check for availability: - LM2903MXEP, LM2903NEP, LM2903ITLEP, LM2903ITLXEP. Parts listed
with an "X" are provided in Tape & Reel and parts without an "X" are in Rails.
Note 2: FOR ADDITIONAL ORDERING AND PRODUCT INFORMATION, PLEASE VISIT THE ENHANCED PLASTIC WEB SITE AT: www.national.com/
mil
Note 3: Refer to package details under Physical Dimensions
March 2005
LM2903EP Low Power Low Offset Voltage Dual Comparators
© 2005 National Semiconductor Corporation DS201141 www.national.com
Schematic and Connection Diagrams
Dual-In-Line/SOIC Package
20114102
20114101
micro SMD
20114145
Top View
LM2903EP
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Absolute Maximum Ratings (Note 14)
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage, V
+
36V
Differential Input Voltage (Note 12) 36V
Input Voltage −0.3V to +36V
Input Current (V
IN
<−0.3V) (Note 7) 50 mA
Power Dissipation (Note 4)
Molded DIP 780 mW
Small Outline Package 510 mW
Output Short-Circuit to Ground
(Note 6) Continuous
Operating Temperature Range −40˚C to +85˚C
Storage Temperature Range −65˚C to +150˚C
Soldering Information
Dual-In-Line Package
Soldering (10 seconds) 260˚C
Small Outline Package 215˚C
Vapor Phase (60 seconds)
Infrared (15 seconds) 220˚C
ESD rating
(1.5 kΩin series with 100 pF) 1300V
Electrical Characteristics (Note 5)
(V
+
=5V, T
A
= 25˚C, unless otherwise stated)
Parameter Conditions LM2903 Units
Min Typ Max
Input Offset Voltage (Note 13) 2.0 7.0 mV
Input Bias Current I
IN
(+) or I
IN
(−) with Output In 25 250 nA
Linear Range, V
CM
= 0V (Note 9)
Input Offset Current I
IN
(+)−I
IN
(−) V
CM
= 0V 5.0 50 nA
Input Common Mode V+ = 30V (Note 10) 0 V+−1.5 V
Voltage Range
Supply Current R
L
=∞V
+
=5V 0.4 1.0 mA
V
+
=36V 1 2.5 mA
Voltage Gain R
L
≥15 kΩ,V
+
=15V 25 100 V/mV
V
O
=1Vto11V
Large Signal Response V
IN
=TTL Logic Swing, V
REF
=1.4V 300 ns
Time V
RL
=5V, R
L
=5.1 kΩ
Response Time V
RL
=5V, R
L
=5.1 kΩ(Note 11) 1.5 µs
Output Sink Current V
IN
(−)=1V, V
IN
(+)=0, V
O
≤1.5V 6.0 16 mA
Saturation Voltage V
IN
(−)=1V, V
IN
(+)=0, I
SINK
≤4 mA 250 400 mV
Output Leakage Current V
IN
(−)=0, V
IN
(+)=1V, V
O
=5V 0.1 nA
Electrical Characteristics (Notes 4, 5)
(V+ = 5V)
Parameter Conditions LM2903 Units
Min Typ Max
Input Offset Voltage (Note 13) 9 15 mV
Input Offset Current I
IN(+)
−I
IN(−)
,V
CM
=0V 50 200 nA
Input Bias Current I
IN
(+) or I
IN
(−) with Output in
Linear Range, V
CM
=0V
(Note 9)
200 500 nA
Input Common Mode
Voltage Range
V
+
=30V (Note 10) 0 V
+
−2.0 V
Saturation Voltage V
IN
(−)=1V, V
IN
(+)=0,
I
SINK
≤4mA
400 700 mV
Output Leakage Current V
IN
(−)=0, V
IN(+)
=1V, V
O
=30V 1.0 µA
Differential Input Voltage Keep All V
IN
’s≥0V (or V
−
,if
Used), (Note 12)
36 V
LM2903EP
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Electrical Characteristics (Notes 4, 5) (Continued)
Note 4: For operating at high temperatures, the LM2903EP must be derated based on a 125˚C maximum junction temperature and a thermal resistance of 170˚C/W
which applies for the device soldered in a printed circuit board, operating in a still air ambient. The low bias dissipation and the “ON-OFF” characteristic of the outputs
keeps the chip dissipation very small (PD≤100 mW), provided that the output transistors are allowed to saturate.
Note 5: "Testing and other quality control techniques are used to the extent deemed necessary to ensure product performance over the specified temperature
range. Product may not necessarily be tested across the full temperature range and all parameters may not necessarily be tested. In the absence of specific
PARAMETRIC testing, product performance is assured by characterization and/or design."
Note 6: Short circuits from the output to V+can cause excessive heating and eventual destruction. When considering short circuits to ground, the maximum output
current is approximately 20 mA independent of the magnitude of V+.
Note 7: This input current will only exist when the voltage at any of the input leads is driven negative. It is due to the collector-base junction of the input PNP
transistors becoming forward biased and thereby acting as input diode clamps. In addition to this diode action, there is also lateral NPN parasitic transistor action
on the IC chip. This transistor action can cause the output voltages of the comparators to go to the V+voltage level (or to ground for a large overdrive) for the time
duration that an input is driven negative. This is not destructive and normal output states will re-establish when the input voltage, which was negative, again returns
to a value greater than −0.3V.
Note 8: These specifications are limited to −40˚C≤TA≤+85˚C.
Note 9: The direction of the input current is out of the IC due to the PNP input stage. This current is essentially constant, independent of the state of the outputso
no loading change exists on the reference or input lines.
Note 10: The input common-mode voltage or either input signal voltage should not be allowed to go negative by more than 0.3V. The upper end of the
common-mode voltage range is V+−1.5V at 25˚C, but either or both inputs can go to 36V without damage, independent of the magnitude of V+.
Note 11: The response time specified is for a 100 mV input step with 5 mV overdrive. For larger overdrive signals 300 ns can be obtained, see typical performance
characteristics section.
Note 12: Positive excursions of input voltage may exceed the power supply level. As long as the other voltage remains within the common-mode range, the
comparator will provide a proper output state. The low input voltage state must not be less than −0.3V (or 0.3V below the magnitude of the negative power supply,
if used).
Note 13: At output switch point, VO.1.4V, RS=0Ωwith V+from 5V to 30V; and over the full input common-mode range (0V to V+−1.5V), at 25˚C.
Note 14: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur.
Note 15: The LM193 within this data sheet’s graphics is referenced because of it’s a similarity to the LM2903, however is not offered in this data sheet.
LM2903EP
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Typical Performance Characteristics
Supply Current Input Current
20114130 20114131
Output Saturation Voltage
Response Time for Various Input Overdrives — Negative
Transition
20114132
20114133
Response Time for Various Input Overdrives — Positive
Transition
20114134
LM2903EP
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Application Hints
The LM2903EP is a high gain, wide bandwidth device which,
like most comparators, can easily oscillate if the output lead
is inadvertently allowed to capacitively couple to the inputs
via stray capacitance. This shows up only during the output
voltage transition intervals as the comparator change states.
Power supply bypassing is not required to solve this prob-
lem. Standard PC board layout is helpful as it reduces stray
input-output coupling. Reducing the input resistors to
<10 kΩreduces the feedback signal levels and finally,
adding even a small amount (1.0 to 10 mV) of positive
feedback (hysteresis) causes such a rapid transition that
oscillations due to stray feedback are not possible. Simply
socketing the IC and attaching resistors to the pins will cause
input-output oscillations during the small transition intervals
unless hysteresis is used. If the input signal is a pulse
waveform, with relatively fast rise and fall times, hysteresis is
not required.
All input pins of any unused comparators should be tied to
the negative supply.
The bias network of the LM2903EP establishes a drain
current which is independent of the magnitude of the power
supply voltage over the range of from 2.0 V
DC
to 30 V
DC
.
It is usually unnecessary to use a bypass capacitor across
the power supply line.
The differential input voltage may be larger than V
+
without
damaging the device (Note 12). Protection should be pro-
vided to prevent the input voltages from going negative more
than −0.3 V
DC
(at 25˚C). An input clamp diode can be used
as shown in the applications section.
The output of the LM2903EP is the uncommitted collector of
a grounded-emitter NPN output transistor. Many collectors
can be tied together to provide an output OR’ing function. An
output pull-up resistor can be connected to any available
power supply voltage within the permitted supply voltage
range and there is no restriction on this voltage due to the
magnitude of the voltage which is applied to the V
+
terminal
of the LM2903EP package. The output can also be used as
a simple SPST switch to ground (when a pull-up resistor is
not used). The amount of current which the output device
can sink is limited by the drive available (which is indepen-
dent of V
+
) and the βof this device. When the maximum
current limit is reached (approximately 16mA), the output
transistor will come out of saturation and the output voltage
will rise very rapidly. The output saturation voltage is limited
by the approximately 60Ωr
SAT
of the output transistor. The
low offset voltage of the output transistor (1.0mV) allows the
output to clamp essentially to ground level for small load
currents.
Typical Applications (V
+
=5.0 V
DC
) (Note 15)
Basic Comparator Driving CMOS Driving TTL
20114135
20114136 20114137
Squarewave Oscillator Pulse Generator Crystal Controlled Oscillator
20114138
20114139
* For large ratios of R1/R2,
D1 can be omitted.
20114140
LM2903EP
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Typical Applications (V
+
=5.0 V
DC
) (Note 15) (Continued)
Two-Decade High Frequency VCO
20114141
V* = +30 VDC
+250 mVDC ≤VC≤+50 VDC
700Hz ≤fo≤100kHz
Basic Comparator Non-Inverting Comparator with Hysteresis
20114106
20114109
Inverting Comparator with Hysteresis Output Strobing
20114110
20114111
LM2903EP
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Typical Applications (V
+
=5.0 V
DC
) (Note 15) (Continued)
Zero Crossing Detector (Single Power Supply) One-Shot Multivibrator
20114121 20114122
Bi-Stable Multivibrator One-Shot Multivibrator with Input Lock Out
20114124
20114123
Zero Crossing Detector Comparator With a Negative Reference
20114143 20114144
LM2903EP
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Physical Dimensions inches (millimeters) unless otherwise noted
SOIC Package
NS Package Number M08A
Molded Dual-In-Line Package (N)
NS Package N08E
LM2903EP
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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
8–Bump (12 mil) micro SMD Package
NS Package TLA08AAA
X
1
= 1,514mm X
2
= 1.514mm X
3
= 0.600mm
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves
the right at any time without notice to change said circuitry and specifications.
For the most current product information visit us at www.national.com.
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LM2903EP Low Power Low Offset Voltage Dual Comparators
