Electrical Characteristics (Note 1) (Continued)

Note 4: Refer to RETS137H drawing for LM137H or RETS137K drawing for LM137K military specifications.

Schematic Diagram

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Thermal Regulation

When power is dissipated in an IC, a temperature gradient

occurs across the IC chip affecting the individual IC circuit

components. With an IC regulator, this gradient can be es-

pecially severe since power dissipation is large. Thermal

regulation is the effect of these temperature gradients on

output voltage (in percentage output change) per Watt of

power change in a specified time. Thermal regulation error is

independent of electrical regulation or temperature coeffi-

cient, and occurs within 5 ms to 50 ms after a change in

power dissipation. Thermal regulation depends on IC layout

as well as electrical design. The thermal regulation of a

voltage regulator is defined as the percentage change of

V

applied. The LM137’s specification is 0.02%/W, max.

00906703

Vertical sensitivity, 5 mV/div

FIGURE 1.

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