lm614amn National Semiconductor Corporation, lm614amn Datasheet - Page 14

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

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Application Information
R1 = Vr/I = 1.24/32µ = 39k
R2 = R1 {(Vro/Vr) − 1} = 39k {(5/1.24) − 1)} = 118k
Understanding that V
resistors, and capacitors may be tied to the FEEDBACK pin,
a range of V
FIGURE 6. Output Voltage has Negative Temperature
FIGURE 7. Output Voltage has Positive TC
FIGURE 5. Resistors R1 and R2 Program
Coefficient (TC) if R2 has Negative TC
Reference Output Voltage to be 5V
r
temperature coefficients may be synthesized.
if R1 has Negative TC
r
is fixed and that voltage sources,
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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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