AH277AZ4-BG1 Diodes Incorporated

Data Sheet COMPLEMENTARY OUTPUT HALL EFFECT LATCH AH277A General Description Features The AH277A is an integrated Hall sensor with output On-Chip Hall Sensor driver designed for electronic commutation of brush- 3.5V to 16V Supply Voltage less DC motor applications. The device includes an on- 400mA (avg) Output Sink Current chip Hall sensor for magnetic sensing, an amplifier Reversed Supply Voltage Protection that amplifies the Hall voltage, a Schmitt trigger to o o -20 C to 85 C Operating Temperature provide switching hysteresis for noise rejection, a tem- Low Profile TO-94 (SIP-4L) Package perature compensation circuit to compensate the tem- ESD Rating: 300V (Machine Model) perature drift of Hall sensitivity and two complementary open-collector drivers for sinking large load current. It also includes an internal band-gap Applications regulator which is used to provide bias voltage for internal circuits. Dual-Coil Brushless DC Motor Dual-Coil Brushless DC Fan Placing the device in a variable magnetic field, if the Revolution Counting magnetic flux density is larger than threshold B , the OP Speed Measurement 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 B RP, then causes DO to be turned high (off) and DOB turned low (on). AH277A is available in TO-94 (SIP-4L) package. TO-94 Figure 1. Package Type of AH277A Oct. 2009 Rev. 1. 6 BCD Semiconductor Manufacturing Limited 1 Data Sheet COMPLEMENTARY OUTPUT HALL EFFECT LATCH AH277A Pin Configuration Z4 Package (TO-94) 4 GND 3 DOB 2 DO 1 V CC Figure 2. Pin Configuration of AH277A (Front View) Pin Description Pin Number Pin Name Function V 1 Supply voltage CC 2 DO Output 1 3 DOB Output 2 4 GND Ground Oct. 2009 Rev. 1. 6 BCD Semiconductor Manufacturing Limited 2