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Voltage-to-frequency converter

LM331 Working Principle

Learn how LM331 works with an illustrated explanation and practical readings.

LM331 at a glance

Follow the labeled connections and functional stages

LM331 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

Compare

The comparator compares filtered VIN with the integrated feedback voltage.

Step 2 / 3

Deliver charge

A timed pulse routes reference current into the integration network.

Step 3 / 3

Balance and count

The repetition rate settles so average feedback follows VIN. Count FOUT pulses to recover the input level.

Component view