lm614amn National Semiconductor Corporation, lm614amn Datasheet - Page 15

• Manufacturer Part Number: lm614amn
• Description: Quad Operational Amplifier And Adjustable Reference
• Manufacturer: National Semiconductor Corporation

Application Information
Hysteresis
The reference voltage depends, slightly, on the thermal his-
tory
vary — always check the data sheet for any given device. Do
not assume that no specification means no hysteresis.
OPERATIONAL AMPLIFIERS
Any amp or the reference may be biased in any way with no
effect on the other amps or reference, except when a sub-
strate diode conducts (see Guaranteed Electrical Character-
istics (Note 1)). One amp input may be outside the
common-mode range, another amp may be operated as a
comparator, another with all terminals floating with no effect
on the others (tying inverting input to output and
of
FIGURE 11. Negative-TC Current Source
the
die.
Competitive
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(Continued)
products
15
non-inverting input to V
Choosing operating points that cause oscillation, such as
driving too large a capacitive load, is best avoided.
Op Amp Output Stage
These op amps, like their LM124 series, have flexible and
relatively wide-swing output stages. There are simple rules
to optimize output swing, reduce cross-over distortion, and
optimize capacitive drive capability:
1. Output Swing: Unloaded, the 42µA pull-down will bring
2. Cross-over Distortion: The LM614 has lower cross-over
3. Capacitive Drive: Limited by the output pole caused by
Op Amp Input Stage
The lateral PNP input transistors, unlike most op amps, have
BV
they have no diode clamps to the positive supply nor across
the inputs. These features make the inputs look like high
impedances to input sources producing large differential and
common-mode voltages.
EBO
the output within 300 mV of V
ture range. If more than 42µA is required, a resistor from
output to V
improved slightly if the load can be tied to V
of poorer sinking open-loop voltage gain
distortion (a 1 V
LM124), and increased slew rate as shown in the char-
acteristic curves. A resistor pull-up or pull-down will force
class-A operation with only the PNP or NPN output
transistor conducting, eliminating cross-over distortion
the output resistance driving capacitive loads, a
pull-down resistor conducting 1 mA or more reduces the
output stage NPN r
the current limit 25 . 200pF may then be driven without
oscillation.
equal to the absolute maximum supply voltage. Also,
−
will help. Swing across any load may be
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e
until the output resistance is that of
−
deadband versus 3 V
on unused amps is preferred).
−
over the military tempera-
+
, at the cost
www.national.com
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for the