AH5798

AH5798
SINGLE PHASE HALL EFFECT LATCH SMART
FAN MOTOR CONTROLLER
Description
Pin Assignments
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.
( Top View )
Vdd 1
5 FG
2
NC
O1 3
74 O2
Vss
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.
SOT89-5L
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.
( Top View)
The AH5798 is available in space saving SOT89-5L and
thinner TSOT25 packages.
FG
1
Vss
2
O2
3
5
Vdd
4
O1
Features
TSOT25
•
•
•
•
•
•
•
•
•
•
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
AH5798
Document number: DS32001 Rev. 2 - 2
Applications
•
•
•
3.3V / 5V Min. BLDC Cooling Fans
Netbook/ Notebook BLDC fans
Low Voltage/ Low Power BLDC Motors
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AH5798
SINGLE PHASE HALL EFFECT LATCH SMART
FAN MOTOR CONTROLLER
Typical Application Circuit
SYSTEM
POWER
10Kohm
SYSTEM
POWER
Vdd
FG
FG
D1
C1
Dz
AH5798
O1
O2
V SS
* Reverse connection of power supply may damage the device. To prevent reverse power damage, a protection (reverse blocking)
Diode D1 is needed between power supply and Vdd terminal. If a reverse power protection diode D1 is used, there
is no current return path to power supply, so it is necessary to follow measures such as below.
- Connect Dz (Zener diode) between Vdd and Vss terminal, to prevent voltage exceeding the absolute maximum rating of the device.
- Connect a capacitor C1 between Vdd and Vss terminal, to complete the current return path to power supply.
The AH5798 has an open-drain tachometer FG output that follows the magnetic change frequency. Typically, a pull-up resistor of 10kΩ is
recommended from FG pin to the supply voltage.
Pin Descriptions
Pin Name
Notes:
Description
Vdd
Power Supply Pin
Vss
Ground Pin
O1
Output Driving & Sinking Pin 1
O2
Output Driving & Sinking Pin 2
NC
No Connection
FG
Frequency Generator (Note 1)
1. The FG is the same as the magnetic change frequency.
AH5798
Document number: DS32001 Rev. 2 - 2
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AH5798
SINGLE PHASE HALL EFFECT LATCH SMART
FAN MOTOR CONTROLLER
Functional Block Diagram
Vdd
FG
Power
Frequency
Generator
O1
Hall
Sensor
AMP
Control
Logic
Soft Switching
Control
Full Bridge
Driver
O2
Lock detect,
Shoutdown and
Automatic re-start
Vss
Operating
Magentic
S
N
O2
O1
Ton
FG
Normal spinning
Toff
Mechanical lock
motor locked detected
Notes:
“Re-start spinning”
motor locked cleared
2. In “Normal spinning”, the FG changes its state at each rising edge of O1.
3. When the motor locks with South pole at the Hall element, O2 is kept on “L” and O1 is a clock with Ton/Toff ratio. When motor
locks with North pole at the Hall element, O1 is kept on “L”, O2 is a clock with Ton/Toff ratio.
4. When “Re-start spinning” occurs, the motor speed ramps up to the “Normal Spinning” speed from zero. Speed ramp-up profile
depends on motor characteristics.
AH5798
Document number: DS32001 Rev. 2 - 2
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AH5798
SINGLE PHASE HALL EFFECT LATCH SMART
FAN MOTOR CONTROLLER
Soft Switching
AH5798 employs soft switching of output drive at commutation to reduce audible noise and EMI for low noise
applications.
Vdd
Vout 1
Vout 2
GND
100µs typ.
Absolute Maximum Ratings (TA = 25°C, unless otherwise noted)
Symbol
Vdd
IO(PEAK)
PD
Parameter
Rating
6
800
800
520
-65 ~ 150
156
240
Supply voltage
Maximum Output Current (Peak)
SOT89-5L
TSOT25
Power Dissipation
TST
Storage Temperature Range
θJA
Thermal Resistance Junction-to-Ambient
(Note 5)
SOT89-5L
TSOT25
Unit
V
mA
mW
mW
o
C
o
C/W
o
C/W
TA
TJ
Tc
θ JA
θ JC
Notes:
5. θJA should be confirmed with heat sink thermal resistance. If there is no heat sink contact, θJA will almost be the same as θJC.
Recommended Operating Conditions (TA = 25°C)
Symbol
Vdd
TA
Parameter
Supply Voltage
Operating Ambient Temperature Range
AH5798
Document number: DS32001 Rev. 2 - 2
Conditions
Min
Max
Unit
Operating
Operating
1.8
-40
5.5
105
°C
V
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AH5798
SINGLE PHASE HALL EFFECT LATCH SMART
FAN MOTOR CONTROLLER
Electrical Characteristics (TA = 25°C, Vdd = 5V)
Symbol
Idd
VOH
VOL
TSW
ILEAK
VFGOL
TON
RDR
Parameter
Test Conditions
Supply Current
Output Voltage High
Output Voltage Low
Output Switching Slope Duration
FG Output Leakage Current
FG Output Voltage Low
On Time
Duty Ratio
No Load
IOUT = 300mA
IOUT = 300mA
50Ω load on out1/out2
IFG = 5mA
TOFF / TON
Min
Typ.
Max
Unit
4.4
350
-
5
4.65
0.35
100
500
10
0.6
5
0.4
650
-
mA
V
V
μs
μA
V
ms
Magnetic Characteristics (TA = 25°C, Vdd = 1.8V~5V, Note 6)
Symbol
Bop
Brp
Bhy
Notes:
Parameter
Operate Point
Release Point
Hysteresis
Min
Typ.
(1mT = 10 G)
Max
Unit
10
-50
-
25
-25
50
50
-10
-
G
G
G
6. The magnetic characteristics may vary with supply voltage, operating temperature and after soldering.
AH5798
Document number: DS32001 Rev. 2 - 2
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AH5798
SINGLE PHASE HALL EFFECT LATCH SMART
FAN MOTOR CONTROLLER
Operating Characteristics
O1
O2
VOH
RP
OFF
ON
OP
Output Voltage in Volts
Output Voltage in Volts
VOH
VOL
Brp
0
OFF
OP
RP
ON
VOL
Bop
Brp
Magnetic Flux Density in Gauss
0
Magnetic Flux Density in Gauss
S
N
Marking side
Marking side
N
S
(SOT89-5L)
(TSOT25)
AH5798
Document number: DS32001 Rev. 2 - 2
Bop
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AH5798
SINGLE PHASE HALL EFFECT LATCH SMART
FAN MOTOR CONTROLLER
Performance Characteristics
(1) SOT89-5L
TA (°C)
PD (mW)
TA (°C)
PD (mW)
25
800
105
288
50
640
110
256
60
576
115
224
P D (m W )
70
512
120
192
75
480
125
160
80
448
130
128
85
416
135
96
90
384
140
64
95
352
145
32
100
320
150
0
Pow er D iss ipation C urve
900
800
700
600
500
400
300
200
100
0
-400
25
50
75
10 0 105
125
1 50
T A (°C )
(2) TSOT25
TA (°C)
PD (mW)
TA (°C)
PD (mW)
25
520
105
188
50
417
110
167
60
375
115
146
P D (m W )
70
333
120
125
75
313
125
104
80
292
130
83
85
271
135
63
90
250
140
42
95
230
145
21
100
208
150
0
Pow er Diss ipation C urv e
60 0
52 0
50 0
40 0
30 0
20 0
10 0
0
-400
25
50
75
10 0
12 5
150
1 05
T A (°C)
AH5798
Document number: DS32001 Rev. 2 - 2
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AH5798
SINGLE PHASE HALL EFFECT LATCH SMART
FAN MOTOR CONTROLLER
Ordering Information
AH 5798 - XX G - X
Green
Packing
G : Green
7/13 : Tape & Reel
Package
Y : SOT89-5L
WT : TSOT25
Device
AH5798-YG-13
AH5798-WTG-7
Notes:
Package
Code
Y
WT
7”/13” Tape and Reel
Quantity
Part Number Suffix
2500/Tape & Reel
-13
3000/Tape & Reel
-7
Packaging
(Note 7 & 8)
SOT89-5L
TSOT25
7. Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at
http://www.diodes.com/datasheets/ap02001.pdf
8. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied. Please visit our website at
http://www.diodes.com/products/lead_free.html
Marking Information
(1) SOT89-5L
(Top View)
4
7
5
XX Y W X
1
2
3
Part Number
AH5798-YG
XX : Identification code
Y : Year : 0~9
W : Week : A~Z : 1~26 week;
a~z : 27~52 week;
z represents 52 and 53 week
X : Internal code
A~Z : Green
Package
SOT89-5L
Identification Code
K4
(2) TSOT25
(Top View)
4
7
5
XX Y W X
1
2
Part Number
AH5798-WTG
AH5798
Document number: DS32001 Rev. 2 - 2
3
XX : Identification code
Y : Year 0~9
W : Week : A~Z : 1~26 week;
a~z : 27~52 week;
z represents 52 and 53 week
X : A~Z : Green
Package
TSOT25
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Identification Code
K4
June 2010
© Diodes Incorporated
AH5798
SINGLE PHASE HALL EFFECT LATCH SMART
FAN MOTOR CONTROLLER
Package Outline Dimensions (All Dimensions in mm)
(1) Package type: SOT89-5L
Sensor Location
AH5798
Document number: DS32001 Rev. 2 - 2
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AH5798
SINGLE PHASE HALL EFFECT LATCH SMART
FAN MOTOR CONTROLLER
Package Outline Dimensions (Continued)
(2) Package type: TSOT25
Sensor Location
AH5798
Document number: DS32001 Rev. 2 - 2
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AH5798
SINGLE PHASE HALL EFFECT LATCH SMART
FAN MOTOR CONTROLLER
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DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
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LIFE SUPPORT
Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without
the express written approval of the Chief Executive Officer of Diodes Incorporated. As used herein:
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A critical component is any component in a life support device or system whose failure to perform can be reasonably expected
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Incorporated products in such safety-critical, life support devices or systems.
Copyright © 2010, Diodes Incorporated
www.diodes.com
AH5798
Document number: DS32001 Rev. 2 - 2
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