AH2984
TWO PHASE HALL-EFFECT SMART FAN MOTOR CONTROLLER
Description
The AH2984 is a single-chip solution for driving two-coil brushless
direct current (BLDC) fans and motors. The device includes a Hall-
effect sensor, dynamic offset correction and two complementary
open-drain output drivers with internal Zener diode protection. It is
optimized for low start-up voltage.
Pin Assignments
(Top View)
AH2984
To help protect the motor coils, the AH2984 provides Rotor Lock
Protection which shuts down output drives 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.
The AH2984 is available in SIP4 and SOT89-5 packages.
12 3 4
SIP-4
1 : VDD
2 : DO
3 : DOB
4 : GND
(Top View)
Features
• Single-chip solution
• Operating Voltage: 2.5V to 15V
• Built-in Hall sensor and input amplifier
• Rotor Lock Protection (Lock detection, output shutdown and
automatic re-start)
• Built-in reverse voltage protection diode
• Built-in Zener protection for output drivers
• Average output current up to 500mA
• Packages: SIP-4 and SOT89-5
• “Green” Molding Compound
• Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
• Halogen and Antimony Free. “Green” Device (Note 3)
Vdd 1
5 NC
GND 2 AH2984
GND
DO 3
74 DOB
SOT89-5
Applications
• Two-coil BLDC Cooling Fans
• Low Voltage/ Low Power BLDC Motors
Notes:
1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.
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.
AH2984
Document number: DS31698 Rev. 4 - 2
1 of 10
www.diodes.com
December 2013
© Diodes Incorporated
Performance Characteristics
(1) SIP-4
TA(C)
PD(mW)
TA(C)
PD(mW)
PD (mW)
25
550
105
198
600
500
400
300
200
100
0
-400
50 60 70 80
440 396 352 308
110 115 120 125
176 154 132 110
Power Dissipation Curve
25 50 75
AH2984
85 90 95 100
286 264 242 220
130 135 140 150
88 66 44
0
100
105
125 150
TA (oC)
(2) SOT89-5
TA (C)
PD (mW)
TA (C)
PD (mW)
25 50 60 70 75 80 85 90 95 100
800 640 576 512 480 448 416 384 352 320
105 110 115 120 125 130 135 140 145 150
288 256 224 192 160 128 96 64 32 0
PD (mW)
900
800
700
600
500
400
300
200
100
0
0
-40
Power Dissipation Curve
25 50 75 100 125 150
105
TA (°C)
AH2984
Document number: DS31698 Rev. 4 - 2
6 of 10
www.diodes.com
December 2013
© Diodes Incorporated
