The AH278 is an integrated Hall sensor with output
driver designed for electronic commutation of brush-
less DC motor applications. The device includes an on-
chip Hall sensor for magnetic sensing, an amplifier
that amplifies the Hall voltage, a Schmitt trigger to
provide switching hysteresis for noise rejection and
two complementary open-collector drivers for sinking
large load current. It also includes an internal band-gap
regulator which is used to provide bias voltage for
internal circuits and allows a wide operating supply
voltage ranges.
Placing the device in a variable magnetic field, if the
magnetic flux density is larger than threshold BOP, the
pin DO will be turned low (on) and pin DOB will be
turned high (off). This output state is held until the
magnetic flux density reverses and falls below BRP,
then causes DO to be turned high (off) and DOB
turned low (on).
AH278 is available in TO-94 (SIP-4L) package.