The Allegro A1101 Hall-effect switch is a tiny sensor IC for use in magnetically activated switch applications. It can operate on 4-24 VDC and its output is rated at 25mA.
The output of these devices switches low (turns on) when a magnetic field (south polarity) perpendicular to the Hall sensor exceeds the operate point threshold. After turn-on, the output is capable of sinking 25mA. When the magnetic field is reduced below the release point, the device output goes high (turns off). The built-in hysteresis allows clean switching of the output, even in the presence of external mechanical vibration and electrical noise.
The A1101's sensitivity is ideal for tachometer sensing applications (just trigger it with a small neodymium magnet mounted on the moving shaft).
Features:
Single 3.8VDC to 24VDC supply
25mA "open collector" output
Hysteresis ensures clean on/off switching
High sensitivity
3-lead (through-hole) SIP package
Direct replacement for the popular A3141 IC
RoHS compliant
