LM613IWMX National Semiconductor, LM613IWMX Datasheet - Page 20

• Manufacturer Part Number: LM613IWMX
• Description: IC,Operational Amplifier,DUAL,BIPOLAR,SOP,16PIN,PLASTIC
• Manufacturer: National Semiconductor

Specifications of LM613IWMX

• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

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Application Information
Connecting a resistor across Cathode-to-FEEDBACK cre-
ates a 0 TC current source, but a range of TCs may be
synthesized.
I = Vr/R1 = 1.24/R1
FIGURE 8. Diode in Series with R1 Causes Voltage
FIGURE 10. Proportional-to-Absolute-Temperature
Across R1 and R2 to be Proportional to Absolute
FIGURE 9. Current Source is Programmed by R1
Temperature (PTAT)
Current Source
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(Continued)
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20
Reference Hysteresis
The reference voltage depends, slightly, on the thermal his-
tory of the die. Competitive micro-power products vary —
always check the data sheet for any given device. Do not
assume that no specification means no hysteresis.
OPERATIONAL AMPLIFIERS AND COMPARATORS
Any amp, comparator, or the reference may be biased in any
way with no effect on the other sections of the LM613,
except when a substrate diode conducts, see Electrical
Characteristics (Note 1). For example, one amp input may
be outside the common-mode range, another amp may be
operating as a comparator, and all other sections may have
all terminals floating with no effect on the others. Tying
inverting input to output and non-inverting input to V
unused amps is preferred. Unused comparators should have
non-inverting input and output tied to V
tied to V
such as driving too large a capacitive load, is best avoided.
Op Amp Output Stage
These op amps, like the 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 42 µA pull-down will bring
2. Cross-Over Distortion: The LM613 has lower cross-over
3. Capacitive Drive: Limited by the output pole caused by
the output within 300 mV of V
ture range. If more than 42 µA 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 25Ω. 200 pF may then be driven without
oscillation.
FIGURE 11. Negative-TC Current Source
−
. Choosing operating points that cause oscillation,
−
will help. Swing across any load may be
BE
e
until the output resistance is that of
deadband versus 3 V
−
00922639
over the military tempera-
+
, and inverting input
+
, at the cost
BE
for the
−
on