应用

双线圈无刷直流电机·

双线圈无刷直流风扇·

速度测量

General Description

The AH277A is an integrated Hall sensor with output

driver designed for electronic commutation of brushless DC motor applications. The device includes an onchip Hall sensor for magnetic sensing, an amplifier

that amplifies the Hall voltage, a Schmitt trigger to

provide switching hysteresis for noise rejection, a temperature compensation circuit to compensate the temperature drift of Hall sensitivity 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.

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).

AH277A is available in TO-94 (SIP-4L) package.

Features

· On-Chip Hall Sensor

· 3.5V to 16V Supply Voltage

· 400mA (avg) Output Sink Current

· Reversed Supply Voltage Protection

· -20oC to 85oC Operating Temperature

· Low Profile TO-94 (SIP-4L) Package

· ESD Rating: 300V (Machine Model)

Applications

· Dual-Coil Brushless DC Motor

· Dual-Coil Brushless DC Fan

· Revolution Counting

· Speed Measurement