Diodes AH5794 - Manual

AH5794
SINGLE PHASE HALL EFFECT LATCH FAN MOTOR DRIVER
AH5794
Document number: DS35809 Rev. 1 - 2
1 of 13
www.diodes.com
March 2012
© Diodes Incorporated
NEW PROD
UC
T
Description
The AH5794 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.
Low operating voltage down to 1.8V allows motor speed to be
controlled by varying the supply voltage.
To help protect the motor coil, the AH5794 provides Rotor
Lock Protection which shuts down the 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 AH5794 is available in space saving and low profile
TSOT26 and U-DFN2020C-6 packages.
Features
•
Supports single-coil full-wave BLDC fan drivers
•
Built-in Hall sensor and input amplifier
•
Operating voltage: 1.8V to 6V
•
V
DD
voltage speed control
•
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 package: TSOT26 and U-DFN2020C-6
•
Halogen and Antimony free “Green” packages.
•
Lead Free Finish/ RoHS Compliant
Pin Assignments
Applications
•
3V/ 3.3V/ 5V BLDC Cooling Fans
•
Netbook/ Notebook BLDC fans
•
Instruments cooling fans
•
Low Voltage/ Low Power BLDC Motors
TSOT26
(Top View)
1
2
3
6
5
4
NC FG
V
SS
O2
V
DD
O1
U-DFN2020C-6
(Top View)
FG NC 1
2
3
6
5
4
O2
V
SS
V
DD
O1