SINGLE PHASE FULL WAVE
DIRECT PWM MOTOR DRIVER
The AM9468 is a high performance ultra low noise single phase
(single-coil) brushless direct current (BLDC) fan and motor driver. The
integrated full-bridge driver output stage uses a BTL linear driver
architecture to minimize audible switching noise and electromagnetic
interference (EMI) providing a low noise solution.
For system flexibility the motor speed can be controlled by either an
external PWM signal or by a DC voltage or from a thermistor network.
Based on the input signal, the AM9468 adjusts the output duty cycle.
To help protect the motor coil, the AM9468 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. In
case of over voltage, the device shuts down the output drive and
enters standby mode to help prevent over voltage stress on the coil.
Over temperature shutdown provides thermal protection for the
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. Additionally,
a rotor lock detect output is provided by open-drain RD pin.
The AM9468 is available in power capable low profile TSSOP-16
Single-Phase Full Wave BLDC Fan/Motor Drive with BTL Output
(BTL Amplifier Gain = 49dB)
Low Noise Architecture
Wide Operating Voltage Range: 2.4V to 18V
PWM Speed Control with External PWM Input
DC Voltage Speed Control by Adjusting VCONT and RMI
Hall Bias Output: VHB = 1.25V
Built-in Quick Start Circuit
Lock Protection with Automatic Restart
Frequency Generator (FG) Output
Rotor Lock Detection (RD) Output
Current Limit Circuit
RF Defines The Current Limit;
RF = 1Ω will Achieve 250mA Current Limit
Thermal Shut-Down (TSD) Circuit
Lead-Free Finish; RoHS Compliant (Notes 1 & 2)
Halogen and Antimony Free. “Green” Device (Note 3)
• 9V/ 12V / 15V BLDC Cooling Fans and Motors
• CPU Cooling Fans for Notebooks and Desktop BLDC Fans
• Instruments Cooling Fans
• Medium Voltage/ Low Power BLDC Motors
1. EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. All applicable RoHS exemptions applied.
2. See http://www.diodes.com/quality/lead_free.html for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green"
3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and
<1000ppm antimony compounds
Document number: DS38663 Rev. 1 - 2
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