AH277A Datasheet | BCD Semiconductor

Description Features Data Sheet AH277A The AH277A is an integrated Hall sensor with output driver designed for electronic mutation 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 pensation circuit to pensate the temperature drift of Hall sensitivity and two plementary 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). - On-Chip Hall Sensor - 3.5V to 16V Supply Voltage - 400m A (avg) Output Sink Current - Reversed Supply Voltage Protection - -20o C to 85o C 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 AH277A is available in TO-94 (SIP-4L) package. Oct. 2009 Rev. 1. 6 TO-94 Figure 1. Package Type of AH277A BCD Semiconductor Manufacturing Limited 1 PLEMENTARY OUTPUT HALL EFFECT LATCH Pin Configuration Z4 Package (TO-94) 4 GND 3 DOB 2 DO 1 VCC Figure 2. Pin Configuration of AH277A (Front View) Data Sheet AH277A Pin Description Pin Number 1 2 3 4 Pin Name VCC DO DOB GND Supply voltage Output 1 Output 2 Ground Function Oct. 2009 Rev. 1. 6 BCD Semiconductor Manufacturing Limited 2 PLEMENTARY OUTPUT HALL EFFECT LATCH Functional Block Diagram VCC 1 Regulator Temperature pensation Hall Sensor Amplifier Schmitt...