AP358 Diodes, Inc., AP358 Datasheet - Page 12

• Manufacturer Part Number: AP358
• Description: Op Amps Low Power Dual Operational Amplifiers
• Manufacturer: Diodes, Inc.

Application Information
single power supply voltage, have true-differential inputs, and
remain in the linear mode with an input common-mode voltage of
0 V
supply voltage with little change in performance characteristics.
At 25°C amplifier operation is possible down to a minimum supply
voltage of 2.3 V
supply for the integrated circuit never becomes reversed in
polarity or that the unit is not inadvertently installed backwards in
a test socket as an unlimited current surge through the resulting
forward diode within the IC could cause fusing of the internal
conductors and result in a destroyed unit.
accommodated and, as input differential voltage protection
diodes are not needed, no large input currents result from large
differential input voltages. The differential input voltage may be
larger than V
provided to prevent the input voltages from going negative more
than -0.3 V
the IC input terminal can be used.
have 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.
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 prevent crossover distortion. Where the load is
directly coupled, as in dc applications, there is no crossover
distortion.
AP358 Rev. 3
DC
. These amplifiers operate over a wide range of power
The AP358 series are op amps which operate with only a
Precautions should be taken to insure that the power
Large
To reduce the power supply current drain, the amplifiers
For ac applications, where the load is capacitively coupled
DC
+
without damaging the device. Protection should be
(at 25°C). An input clamp diode with a resistor to
differential
DC
.
input
voltages
can
be
www.diodes.com
LOW POWER DUAL OPERATIONAL AMPLIFIERS
12 of 15
easily
the amplifier reduce the loop stability margin. Values of 50pF can
be accommodated using the worst-case non-inverting unity gain
connection. Large closed loop gains or resistive isolation should
be used if larger load capacitance must be driven by the
amplifier.
which is independent of the magnitude of the power supply
voltage over the range of 3 V
power supply should be of short time duration. Units can be
destroyed, 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 excessive
function temperatures. Putting direct short-circuits on more than
one amplifier at a time will increase the total IC power dissipation
to destructive levels, if not properly protected with external
dissipation limiting resistors in series with the output leads of the
amplifiers. The larger value of output source current which is
available at 25°C provides a larger output current capability at
elevated temperatures (see typical performance characteristics)
than a standard IC op amp.
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, introducing a
pseudo-ground (a bias voltage reference of V
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
accommodated.
Capacitive loads which are applied directly to the output of
The bias network of the AP358 establishes a drain current
Output short circuits either to ground or to the positive
The circuits presented in the section on typical
voltages
which
range
DC
to 30 V
to
DC
ground
SEPTEMBER 2006
.
©
Diodes Incorporated
AP358
can
+
/2) will allow
easily be