AM9468

Document number: DS38663 Rev. 1 - 2

1 of 16

www.diodes.com

May 2016

© Diodes Incorporated

AM9468

SINGLE PHASE FULL WAVE

DIRECT PWM MOTOR DRIVER

Description

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

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. Additionally,

a rotor lock detect output is provided by open-drain RD pin.

The AM9468 is available in power capable low profile TSSOP-16

package.

Features



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

Voltage





Built-in Quick Start Circuit



Lock Protection with Automatic Restart



Frequency Generator (FG) Output



Rotor Lock Detection (RD) Output



Current Limit Circuit





Thermal Shut-Down (TSD) Circuit



Lead-Free Finish; RoHS Compliant (Notes 1 & 2)



Halogen and Antimony Free. “Green” Device (Note 3)

Pin Assignments

(Top View)

REGH

5VREG

VCONT

RMI

FG

RD

HIN+

HB

HIN-

CPWM

PWM

GND

3

4

5

6

7

8

14

13

12

11

10

9

RF

OUT2

1

2

16

15

OUT1

TSSOP-16

Applications

•

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

Notes:

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"

and Lead-free.

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

Green