LM321MF National Semiconductor, LM321MF Datasheet - Page 5

• Manufacturer Part Number: LM321MF
• Description: IC, OP-AMP, 1MHZ, 0.4V/µs, SOT-23-5
• Manufacturer: National Semiconductor

Specifications of LM321MF

• Op Amp Type: Low Power
• No. Of Amplifiers: 1
• Bandwidth: 1MHz
• Slew Rate: 0.4V/µs
• Supply Voltage Range: 3V To 22V
• Amplifier Case Style: SOT-23
• No. Of Pins: 5
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Application Hints
The LM321 op amp can operate with a single or dual power
supply voltage, has true-differential inputs, and remain in the
linear mode with an input common-mode voltage of 0 V
This amplifier operates over a wide range of power supply
voltages, with little change in performance characteristics. At
25˚C amplifier operation is possible down to a minimum
supply voltage of 3V.
Large differential input voltages can be easily accommo-
dated and, as input differential voltage protection diodes are
not needed, no large input currents result from large differ-
ential input voltages. The differential input voltage may be
larger than V
should be provided to prevent the input voltages from going
negative more than −0.3 V
with a resistor to the IC input terminal can be used.
To reduce the power supply drain, the amplifier has a class A
output stage for small signal levels which converts to class B
in a large signal mode. This allows the amplifiers to both
source and sink large output currents. Therefore both NPN
and PNP external current boost transistors can be used to
extend the power capability of the basic amplifiers. The
output voltage needs to raise approximately 1 diode drop
above ground to bias the on-chip vertical PNP transistor for
output current sinking applications.
For AC applications, where the load is capacitively coupled
to the output of the amplifier, a resistor should be used, from
the output of the amplifier to ground to increase the class A
bias current and to reduce distortion.
Capacitive loads which are applied directly to the output of
the amplifier reduce the loop stability margin. Values of 50pF
Typical Applications
+
without damaging the device. Protection
DC
(at 25˚C). An input clamp diode
Non-Inverting DC Gain (0V Input = 0V Output)
DC
.
5
can be accommodated using the worst-case non-inverting
unity gain connection. Large closed loop gains or resistive
isolation should be used if large load capacitance must be
driven by the amplifier.
The bias network of the LM321 establishes a supply current
which is independent of the magnitude of the power supply
voltage over the range of from 3 V
Output short circuits either to ground or to the positive power
supply should be of short time duration. Units can be de-
stroyed, not as a result of the short circuit current causing
metal fusing, but rather due to the large increase in IC chip
dissipation which will cause eventual failure due to exces-
sive junction temperatures. The larger value of output source
current which is available at 25˚C provides a larger output
current capability at elevated temperatures than a standard
IC op amp.
The circuits presented in the section on typical applications
emphasize operation on only a single power supply voltage.
If complementary power supplies are available, all of the
standard op amp circuits can be used. In general, introduc-
ing a pseudo-ground (a bias voltage reference of V
allow operation above and below this value in single power
supply systems. Many application circuits are shown which
take advantage of the wide input common-mode voltage
range which includes ground. In most cases, input biasing is
not required and input voltages which range to ground can
easily be accommodated.
DC
to 30 V
20007606
DC
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