Diodes AH9479/80/81 - Manual

Data Sheet
Single Phase Low Noise Smart Motor Driver AH9479/80/81
Mar. 2012 Rev. 1. 1 BCD Semiconductor Manufacturing Limited
1
General Description
The AH9479/80/81 is a single chip solution for
driving single coil brushless DC motors.
It combines
a motor driver with a high sensitivity Hall sensor,
which simplifies the PCB design and makes the
fabrication of small-size motors possible.
The AH9480 has an open-drain tachometer output FG
that follows the Hall sensor latching output. The
AH9481 has an open-drain rotation detection output
RD that is active low when the motor is spinning and
goes high when blocked.
When there is no motion about 0.4 second, the IC
will automatically detect the locked rotor conditions,
and enter protection mode, shutting off the motor
driver for 4 seconds. Then, the IC will turn on the
motor driver for 0.4 second to detect whether there is
rotation condition, if fails, the IC will shut off motor
driver for four seconds again. This sequence will be
repeated until rotation condition is detected, and the
IC enters normal operation. This feature can
effectively prevent the IC from overheating and
damage due to long-time locked rotor condition.
“Soft-switch” is used to reduce the vibration and
acoustic noise. Thermal-shutdown protection ensures
that the motor driver operates under specified
temperature ranges.
The AH9479 is packaged in TO-94, and the
AH9480/81 is packaged in TO-95 and MSOP-8.
Features
• Full Bridge Driver
• High Sensitivity Integrated Hall Sensor
• Soft-switching for Low Noise
• Low Supply Voltage: 2.5V
• Locked Rotor Protection and Auto-restart
• Thermal Protection
• Output Over-current Protection
• Short Circuit Protection
• Tachometer Output Signal (AH9480)
• Alarm Output Signal (AH9481)
Applications
• 5V/12V Low Noise BLDC Cooling Fans
• Low Voltage / Low Power BLDC Motors
• Notebook DC Fans / Blowers
• Automotive Low Noise Climate Control Fans
• Micro-motors
TO-94 TO-95 MSOP-8
Figure 1. Package Types of AH9479/80/81