The M9005 inductive proximity switch IC is used in non‑contact proximity switches to detect the approach of metal objects. Featuring no contacts and fully sealed construction, non‑contact proximity switches deliver long service life, high reliability and fast response speed, and can replace mechanical limit switches. The IC also integrates reliability functions including load overcurrent protection, undervoltage protection and digital temperature compensation.
The chip operates based on the eddy current effect. An oscillator circuit formed by inductor and capacitor senses approaching metal objects. The oscillation remains stable when no metal target is near the inductor. When a metal object approaches, electromagnetic field energy generated by the oscillator circuit is absorbed, reducing the amplitude of the oscillation loop or halting oscillation entirely.