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Voltage-to-frequency converter

LM331 Basic Circuit

Build a basic LM331 circuit with labeled pins, component values and connection guidance.

LM331 in a circuit

15V analog supply,5V frequency output.

LM331NPDIP8with6.8k10nFtimer,100k100nFinputfilter,100k1uFintegrator,47ohmreturn,12kplus5ktrimand10koutputpullup.
Original drawing based on TI Figure14, with optional offset-adjust circuit omitted.

Connect it, step by step

Follow the component values and pin connections

Build the networks

Keep input-filter and integration components close to the IC.

Trim the gain

Apply a known input and adjustRS for the intended output frequency.

Count

Use a5V-compatible counter on FOUT and allow settling.

Component view