Diodes AH5798 User Manual
Ah5798
AH5798
SINGLE PHASE HALL EFFECT LATCH SMART
FAN MOTOR CONTROLLER
AH5798
Document number: DS32001 Rev. 2 - 2
1 of 11
June 2010
© Diodes Incorporated
Description
The AH5798 is a single chip solution for driving single-coil
brushless direct current (BLDC) fans and motors. The
integrated full-bridge driver output stage uses soft switching
to minimize audible switching noise and electromagnetic
interference (EMI) providing a low noise solution.
To help protect the motor coil, the AH5798 provides Rotor
Lock Protection which shuts down output drive if rotor lock is
detected. The device automatically re-starts when the rotor
lock is removed. Over temperature shutdown provides
thermal protection for the device.
A Tachometer output is provided by open-drain Frequency
Generator (FG) Pin which allows external interface to monitor
motor rotation or speed. The FG output is the magnetic
change frequency.
The AH5798 is available in space saving SOT89-5L and
thinner TSOT25 packages.
Features
• Supports single-coil full-wave DC fan drivers
• Built-in Hall sensor and input amplifier
• Operating Voltage: 1.8V to 5.5V
• Soft switching for low noise DC fan motor applications
• Rotor Lock Protection (Lock detection, output shutdown
and automatic re-start)
• Thermal
protection
• Tachometer (FG) output
• No external timing capacitor - Reduces the numbers of
external components required
• Low profile packages: SOT89-5L and TSOT25
• “Green” Molding Compound
Pin Assignments
1
2
3
74
5
O2
O1
Vss
FG
Vdd
( Top View )
NC
SOT89-5L
5
2
4
3
1
( Top View)
O2
Vss
FG
Vdd
O1
TSOT25
Applications
• 3.3V / 5V Min. BLDC Cooling Fans
• Netbook/ Notebook BLDC fans
• Low Voltage/ Low Power BLDC Motors