Diodes AH477A - Manual

SINGLE PHASE HALL EFFECT LATCH AH477A
1
Oct. 2009 Rev. 1. 2 BCD Semiconductor Manufacturing Limited
Data Sheet
General Description
The AH477A is an integrated Hall sensor with H-
bridged output driver designed for brushless DC motor
applications. The device includes an on-chip Hall sen-
sor for magnetic sensing, an amplifier that amplifies
the Hall voltage, a comparator to provide switching
hysteresis for noise rejection, a bi-directional drivers
for sinking and driving large current load. It also
includes an internal bandgap regulator to provide tem-
perature compensated bias for internal circuits and
allows a wide operating supply voltage range.
Placing the device in a variable magnetic field, if the
magnetic flux density is larger than threshold B
OP
, the
DO is turned to sink and DOB is turned to drive. This
output state is held until the magnetic flux density
reverses and falls below B
RP,
then causes DO to be
turned to drive and DOB turned to sink.
The AH477A is available in TO-94 (SIP-4L) package.
Features
· On-Chip Hall Sensor
· Operating Voltage: 3.5V to 18V
· H-Bridge Output Drivers for Single Coil
· Internal Bandgap Regulator for Temperature
Compensation
· Low Output Switching Current Noise
· Operating Temperature: -20 o C to 85 o C
· Low Profile TO-94 (SIP-4L) Package
· ESD Rating: 6000V (Human Body Model)
· Suitable for PWM Power Supply Control Speed
Applications
· Single-coil Brushless DC Motor
· Single-coil Brushless DC Fan
Figure 1. Package Type of AH477A
TO-94