FD166b is including a Hall-Effect sensor with a latched digital output IC in a SOT-23L package. It is suitable for the BLDC motor or magnetic field detection application.

Internal built-in a chopper amplifier for the magnetic signal amplification and let the magnetic sensitivity is more precision and stable, which can achieve low offset and drift magnetic switching characteristics for a wide voltage and temperature operation.

The output pin is active low or high state depends on the flux density and direction of the external magnetic source to the sensor of FD166b IC which is more than threshold of BOP or BRP.