Low Power Low Offset Voltage Dual Comparators
January 1995
Low Power Low Offset Voltage Dual Comparators
General Description
The LM193 series consists of two independent precision
voltage comparators with an offset voltage specification as
low as 2.0 mV max for two comparators which were de-
signed 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. These comparators also have a unique characteris-
tic in that the input common-mode voltage range includes
ground, even though operated from a single power supply
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 LM193 series was
designed to directly interface with TTL and CMOS. When
operated from both plus and minus power supplies, the
LM193 series will directly interface with MOS logic where
their low power drain is a distinct advantage over standard
YHigh precision comparators
YReduced VOS drift over temperature
YEliminates need for dual supplies
YAllows sensing near ground
YCompatible with all forms of logic
YPower drain suitable for battery operation
YWide supply
Voltage range 2.0V to 36V
single or dual supplies g1.0V to g18V
YVery low supply current drain (0.4 mA) Ð independent
of supply voltage
YLow input biasing current 25 nA
YLow input offset current g5nA
and maximum offset voltage g3mV
YInput common-mode voltage range includes ground
YDifferential input voltage range equal to the power sup-
ply voltage
YLow output saturation voltage, 250 mV at 4 mA
YOutput voltage compatible with TTL, DTL, ECL,
MOS and CMOS logic systems
Schematic and Connection Diagrams
Metal Can Package Dual-In-Line Package
Order Number LM193H,
LM193AH, LM193AH/883,
LM293H, LM293AH, LM393H
or LM393AH
See NS Package Number H08C
Order Number LM193J/883*,
LM393J, LM393AJ,
LM393M, LM2903M, LM393N,
LM2903J or LM2903N
See NS Package Number J08A,
M08A or N08E
*Also available per JM38510/11202
C1995 National Semiconductor Corporation RRD-B30M115/Printed in U. S. A.
Absolute Maximum Ratings
If Military/Aerospace specified devices are required, please
contact the National Semiconductor Sales Office/Distributors for
availability and specifications.
(Note 10)
Supply Voltage, Va36V
Differential Input Voltage (Note 8) 36V
Input Voltage b0.3V to a36V
Input Current (VINkb0.3V) (Note 3) 50 mA
Power Dissipation (Note 1)
Molded DIP 780 mW
Metal Can 660 mW
Small Outline Package 510 mW
Output Short-Circuit to Ground (Note 2) Continuous
Operating Temperature Range
LM393/LM393A 0§Ctoa
LM293/LM293A b25§Ctoa
LM193/LM193A b55§Ctoa
LM2903 b40§Ctoa
Storage Temperature Range b65§Ctoa
Lead Temperature (Soldering, 10 seconds) a260§C
Soldering Information
Dual-In-Line Package
Soldering (10 seconds) 260§C
Small Outline Package
Vapor Phase (60 seconds) 215§C
Infrared (15 seconds) 220§C
See AN-450 ‘‘Surface Mounting Methods and Their Effect on Product
Reliability’’ for other methods of soldering surface mount devices.
ESD rating (1.5 kXin series with 100 pF) 1300V
Electrical Characteristics (Vae5V, TAe25§C, unless otherwise stated)
Parameter Conditions LM193A LM293A, LM393A LM193 LM293, LM393 LM2903 Units
Min Typ Max Min Typ Max Min Typ Max Min Typ Max Min Typ Max
Input Offset Voltage (Note 9) 1.0 2.0 1.0 2.0 1.0 5.0 1.0 5.0 2.0 7.0 mV
Input Bias Current IIN(a)orI
IN(b) with Output In Linear 25 100 25 250 25 100 25 250 25 250 nA
Range, VCM e0V (Note 5)
Input Offset Current IIN(a)bIIN(b)V
CM e0V 3.0 25 5.0 50 3.0 25 5.0 50 5.0 50 nA
Input Common Mode Vae30V (Note 6) 0 Vab1.5 0 Vab1.5 0 Vab1.5 0 Vab1.5 0 Vab1.5 V
Voltage Range
Supply Current RLe%Vae5V 0.4 1 0.4 1 0.4 1 0.4 1 0.4 1.0 mA
Vae36V 1 2.5 1 2.5 1 2.5 1 2.5 1 2.5 mA
Voltage Gain RLt15 kX,V
15V 50 200 50 200 50 200 50 200 25 100 V/mV
VOe1V to 11V
Large Signal Response VINeTTL Logic Swing, VREFe1.4V 300 300 300 300 300 ns
Time VRLe5V, RLe5.1 kX
Response Time VRLe5V, RLe5.1 kX(Note 7) 1.3 1.3 1.3 1.3 1.5 ms
Output Sink Current VIN(b)e1V, VIN(a)e0, VOs1.5V 6.0 16 6.0 16 6.0 16 6.0 16 6.0 16 mA
Saturation Voltage VIN(b)e1V, VIN(a)e0, ISINKs4 mA 250 400 250 400 250 400 250 400 250 400 mV
Output Leakage Current VIN(b)e0, VIN(a)e1V, VOe5V 0.1 0.1 0.1 0.1 0.1 nA
Electrical Characteristics (Vae5V) (Note 4)
Parameter Conditions LM193A LM293A, LM393A LM193 LM293, LM393 LM2903 Units
Min Typ Max Min Typ Max Min Typ Max Min Typ Max Min Typ Max
Input Offset Voltage (Note 9) 4.0 4.0 9 9 9 15 mV
Input Offset Current IIN(a)bIIN(b),V
CMe0V 100 150 100 150 50 200 nA
Input Bias Current IIN(a)orI
IN(b) with Output in Linear Range, 300 400 300 400 200 500 nA
VCMe0V (Note 5)
Input Common Mode Voltage Range Vae30V (Note 6) 0 Vab2.0 0 Vab2.0 0 Vab2.0 0 Vab2.0 0 Vab2.0 V
Saturation Voltage VIN(b)e1V, VIN(a)e0, ISINKs4 mA 700 700 700 700 400 700 mV
Output Leakage Current VIN(b)e0, VIN(a)e1V, VOe30V 1.0 1.0 1.0 1.0 1.0 mA
Differential Input Voltage Keep All VIN’st0V (or Vb, if Used), 36 36 36 36 36 V
(Note 8)
Note 1: For operating at high temperatures, the LM393/LM393A and LM2903 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 LM193/LM193A/LM293/LM293A must be derated based on a 150§C maximum junction temperature. The low bias dissipation and the ‘‘ON-OFF’’ characteristic of the outputs keeps the
chip dissipation very small (PDs100 mW), provided the output transistors are allowed to saturate.
Note 2: Short circuits from the output to Vacan 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 Va.
Note 3: 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 Vavoltage 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 b0.3V.
Note 4: These specifications are limited to b55§CsTAsa125§C, for the LM193/LM193A, With the LM293/LM293A all temperature specifications are limited to b25§CsTAsa85§C and the LM393/LM393A temperature specifica-
tions are limited to 0§CsTAsa70§C. The LM2903 is limited to b40§CsTAsa85§C.
Note 5: 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 output so no loading change exists on the reference or input lines.
Note 6: 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 Vab1.5V at 25§C, but either or both inputs can go
to 36V without damage, independent of the magnitude of Va.
Note 7: 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 8: 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 b0.3V (or 0.3V below the magnitude of the negative power supply, if used).
Note 9: At output switch point, VOj1.4V, RSe0Xwith Vafrom 5V to 30V; and over the full input common-mode range (0V to Vab1.5V), at 25§C.
Note 10: Refer to RETS193AX for LM193AH military specifications and to RETS193X for LM193H military specifications.
Typical Performance Characteristics LM193/LM293/LM393, LM193A/LM293A/LM393A
Supply Current Input Current Output Saturation Voltage
Response Time for Various
Input OverdrivesÐNegative
Response Time for Various
Input OverdrivesÐPositive
Typical Performance Characteristics LM2903
Supply Current Input Current Output Saturation Voltage
Response Time for Various
Input OverdrivesÐNegative
Response Time for Various
Input OverdrivesÐPositive
Application Hints
The LM193 series are high gain, wide bandwidth devices
which, like most comparators, can easily oscillate if the out-
put 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 problem. Standard PC board layout is helpful as it
reduces stray input-output coupling. Reducing the input re-
sistors to k10 kXreduces the feedback signal levels and
finally, adding even a small amount (1.0 to 10 mV) of posi-
tive feedback (hysteresis) causes such a rapid transition
that oscillations due to stray feedback are not possible. Sim-
ply socketing the IC and attaching resistors to the pins will
cause input-output oscillations during the small transition in-
tervals unless hysteresis is used. If the input signal is a
pulse waveform, with relatively fast rise and fall times, hys-
teresis is not required.
All pins of any unused comparators should be grounded.
The bias network of the LM193 series establishes a drain
current which is independent of the magnitude of the power
supply voltage over the range of from 2.0 VDC to 30 VDC.
It is usually unnecessary to use a bypass capacitor across
the power supply line.
The differential input voltage may be larger than Vawithout
damaging the device (see Note 8). Protection should be
provided to prevent the input voltages from going negative
more than b0.3 VDC (at 25§C). An input clamp diode can be
used as shown in the applications section.
The output of the LM193 series is the uncommitted collector
of a grounded-emitter NPN output transistor. Many collec-
tors can be tied together to provide an output OR’ing func-
tion. 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 Va
terminal of the LM193 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
independent of Va) and the bof this device. When the
maximum current limit is reached (approximately 16 mA),
the output transistor will come out of saturation and the out-
put voltage will rise very rapidly. The output saturation volt-
age is limited by the approximately 60XrSAT of the output
transistor. The low offset voltage of the output transistor
(1.0 mV) allows the output to clamp essentially to ground
level for small load currents.
Typical Applications (Vae5.0 VDC)
Basic Comparator Driving CMOS Driving TTL
Typical Applications (Continued)
Squarewave Oscillator Pulse Generator Crystal Controlled Oscillator
Two-Decade High-Frequency VCO
*For large ratios of R1/R2,
D1 can be omitted.
V*ea30 VDC
a250 mVDCsVCsa50 VDC
700 Hzsfos100 kHz
Basic Comparator
Non-Inverting Comparator with Hysteresis
Inverting Comparator with Hysteresis
Typical Applications (Continued)
Output Strobing
AND Gate
OR Gate
Large Fan-in AND Gate
Limit Comparator
Comparing Input Voltages
of Opposite Polarity
Typical Applications (Continued)
ORing the Outputs
Zero Crossing Detector (Single Power Supply)
One-Shot Multivibrator
Bi-Stable Multivibrator
One-Shot Multivibrator with Input Lock Out
Typical Applications (Continued) (VaeVDC)
Time Delay Generator
Split-Supply Applications (Vaea15 VDC and Vbeb15 VDC)
MOS Clock Driver
Zero Crossing Detector
Comparator With a
Negative Reference
Physical Dimensions inches (millimeters)
Metal Can Package (H)
Order Number LM193H, LM193H/883, LM193AH, LM193AH/883, LM293H, LM293AH, LM393H or LM393AH
NS Package Number H08C
Order Number LM193J/883, LM193AJ/883 or LM2903J
NS Package Number J08A
Physical Dimensions inches (millimeters) (Continued)
Order Number LM393M or LM2903M
NS Package Number M08A
Low Power Low Offset Voltage Dual Comparators
Physical Dimensions inches (millimeters) (Continued)
Molded Dual-In-Line Package (N)
Order Numbers LM393N or LM2903N
NS Package N08E
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be reasonably expected to result in a significant injury
to the user.
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