LM193AH-QMLV National Semiconductor Corporation, LM193AH-QMLV Datasheet - Page 6

• Manufacturer Part Number: LM193AH-QMLV
• Description: Low Power Low Offset Voltage Dual Comparators
• Manufacturer: National Semiconductor Corporation

www.national.com
Typical Performance Characteristics
Response Time for Various
Input Overdrives — Negative
Transition
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 resistors to
ing 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 hys-
teresis 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 LM193 series establishes a drain
current which is independent of the magnitude of the power
supply voltage over the range of from 2.0 V
It is usually unnecessary to use a bypass capacitor across
the power supply line.
Typical Applications
<
10 k reduces the feedback signal levels and finally, add-
Basic Comparator
DS005709-35
(V
+
= 5.0 V
DS005709-33
DC
DC
to 30 V
)
DC
Driving CMOS
.
Response Time for Various
Input Overdrives — Positive
Transition
LM2903 (Continued)
6
The differential input voltage may be larger than V
damaging the device (Note 8). Protection should be provided
to prevent the input voltages from going negative more than
−0.3 V
shown in the applications section.
The output of the LM193 series 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
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
V
is reached (approximately 16 mA), the output transistor will
come out of saturation and the output voltage will rise very
rapidly. The output saturation voltage is limited by the ap-
proximately 60
voltage of the output transistor (1.0 mV) allows the output to
clamp essentially to ground level for small load currents.
+
) and the of this device. When the maximum current limit
DS005709-36
DC
(at 25˚C). An input clamp diode can be used as
r
SAT
of the output transistor. The low offset
Driving TTL
DS005709-34
DS005709-37
+
+
terminal
without