Description

The AH277A is an integrated Hall sensor with outputdriver designed for electronic commutation of brush-less DC motor applications. The device includes an on-chip Hall sensor for magnetic sensing, an amplifierthat amplifies the Hall voltage, a Schmitt trigger toprovide switching hysteresis for noise rejection, a tem-perature compensation circuit to compensate the tem-perature drift of Hall sensitivity and twocomplementary open-collector drivers for sinkinglarge load current. It also includes an internal band-gapregulator which is used to provide bias voltage forinternal circuits.Placing the device in a variable magnetic field, if themagnetic flux density is larger than threshold BOP, thepin DO will be turned low (on) and pin DOB will beturned high (off). This output state is held until themagnetic flux density reverses and falls below BRP,then causes DO to be turned high (off) and DOBturned low (on).AH277A is available in TO-94 (SIP-4L) package