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5 A adjustable positive regulator

LM338T Working Principle

Learn how LM338T works with an illustrated explanation and practical readings.

LM338T at a glance

Follow the labeled connections and functional stages

LM338T working principle: illustrated functional stages, basic circuit and connections
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How it works

3 stages · Explore one step at a time

Step 1 / 3

Establish the reference

The loop regulates OUTPUT relative to ADJUST; the package has no dedicated ground pin.

Step 2 / 3

Set the ratio and minimum load

110 Ω from OUT to ADJ and 330 Ω from ADJ to ground give a ratio of three. Divider current is approximately 11.27 mA.

Step 3 / 3

Check the thermal path

The 50 Ω load draws about 99.2 mA at 4.96 V. Include divider current when calculating dissipation and selecting a heatsink.

Component view