A3144 TO-92 – Hall Effect Switch

The A3144E(US1881) is an integrated Hall effect latched sensor. That’s nice but what does it do? Holding a magnet near the sensor will cause the output pin to toggle. This makes for a robust presence sensor. A reed sensor also works nicely, but can be limited by the glass encapsulation and size. A hall effect sensor is much smaller, but can handle less current than a reed switch.

The device includes an on-chip Hall voltage generator for magnetic sensing, a comparator that amplifies the Hall voltage, and a Schmitt trigger to provide switching hysteresis for noise rejection, and open-collector output. An internal bandgap regulator is used to provide temperature compensated supply voltage for internal circuits and allows a wide operating supply range.

If a magnetic flux density is larger than threshold Bop, DO is turned on (low). The output state is held until a magnetic flux density reversal falls below Brp causing DO to be turned off (high).

APPLICATIONS:

• Proximity sensing – Detects nearby magnetic fields
• Speed measurement – Used in motor and fan speed monitoring
• Position detection – Determines the position of rotating objects
• Current sensing – Measures electrical current in circuits
• Security systems – Magnetic door and window sensors

Features:

• 3.5V – 24V DC operation
• Low power consumption
• Temperature compensated
• Wide voltage range
• Open-collector pre-driver
• 50mA max sinking output
• Reverse polarity protection
• Lead-free TO-92 package

Package Includes:

• 1 x A3144 TO-92 – Hall Effect Switch