Fairchild FAN8408D 2 phase half wave bldc motor driver Datasheet

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FAN8408D
2 Phase Half Wave BLDC Motor Driver
Features
Description
•
•
•
•
•
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•
The FAN8408D is a monolithic integrated circuit, and
suitable for DC cooling fan motors.
A wide range of operation voltage: 4V to 15V
Built-in motor lock detector.
Automatic restart function
Hall output for a motor speed detection
Built-in thermal shut down circuits
Built-in reverse current protection diode
Compact package: 8-SOP-225
8-SOP-225
1
Typical Applications
• DC cooling fan motor
Ordering Information
Device
Package
Operating Temp.
FAN8408D
8-SOP-225
−25°C ~ 85°C
FAN8408DTF
8-SOP-225
−25°C ~ 85°C
Rev.1.0.4
©2002 Fairchild Semiconductor Corporation
FAN8408D
Block Diagram
OUTB
1
OUTA
7
VCC
4
GND
8
3
LD
2
HO
5
IN+
6
IN-
Commutation &
Control
& TSD
Pin Definitions
2
Pin Number
Pin Name
I/O
Pin Function Description
Remark
1
OUTB
O
Motor output B
2
HO
O
Hall output
3
LD
-
Triangle pulse generator for lock detector
and automatic restart
-
4
VCC
-
Supply voltage
-
5
IN+
I
Hall input +
-
6
IN−
I
Hall input −
-
7
OUTA
O
Motor output A
-
8
GND
-
Ground
-
Open Collector
FAN8408D
Equivalent Circuits
Description
Pin No.
OUTB
1
OUTA
7
Internal Circuit
1
7
Commutation
HO
2
2
Commutation
LD
3
Lock detector
& Automatic
restart
3
Commutation
VLDCP
VLDCL
IN+
5
IN-
6
5
6
Commutation
3
FAN8408D
Absolute Maximum Ratings (Ta = 25°C)
Parameter
Symbol
Maximum power supply voltage
Value
Unit
18
V
VCCMAX
Maximum power dissipationnote1
429note2
PDMAX
mW
620note3
291.61note2
Thermal resistancenote1
ΘJA
Maximum output voltage
VOMAX
30
V
Maximum output current
IOMAX
1.2note4
A
Hall output current
IHO
10
mA
Hall output withstanding voltage
VHO
36
V
VHACMAX
6
V
Maximum hall input ac level
°C/W
201.52note3
Operating temperature
TOPR
−25 ~ 85
°C
Storage temperature
TSTG
−55 ~ 150
°C
Note1:
PCB Condition: Thickness(1.6mm), Dimension(76.2mm * 114.3mm)
Refer: EIA/J SED 51-3 & EIA/J SED 51-7
Note2: Air condition (0m/s)
Note3: Air condition (3m/s)
Note4: Should not exceed PD or ASO value
Pd[W]
Power Dissipation Curve (Air condition = 0m/s)
0.5
0.45
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
0
20
40
60
80
Tc or Ta[°C]
4
100
120
140
160
FAN8408D
Air Speed & ΘJA
350
JA[°C/W]
300
250
200
150
100
50
0
0
1
2
3
4
5
6
Air Speed[m/s]
Recommended Operating Conditions (Ta = 25°C)
Parameter
Symbol
Min.
Typ.
Max.
Unit
VCC
4.0
−
15.0
V
Function compensation operating voltage
Electrical Characteristics
(Ta=25°C, VCC=12V unless otherwise specified)
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Unit
-
-
3.0
mA
Supply current
ICC
When output is off.
Lock detector charging current
ILDC
VLD=1.8V
2.38
3.40
4.42
µA
Lock detector discharging current
ILDD
VLD=1.8V
0.48
0.68
0.88
µA
RCD
RCD=ILDC/ILDD
3.0
5.0
7.0
−
Lock detector capacitor clamp voltage
VLDCL
-
2.4
2.85
3.3
V
Lock detector capacitor comparator voltage
VLDCP
-
0.7
0.99
1.2
V
-
0.9
1.2
V
0
10
µA
Lock detector charging/discharging ratio
Output low level voltage
VOL
Output leakage current
IOL
-
28
30
32
V
-
0.2
0.5
V
IO=200mA
Output zener voltage
VOZ
Clamp current=10mA
Hall output pin low level voltage
VHLL
IO=10mA
Hall output pin leakage current
IHLL
-
-
0
10
µA
Hall input dc range
VHDC
-
1
-
VCC2V
V
Hall input offset
VHOF
VREF=6V
-10
-
10
mV
5
FAN8408D
Application Information
1. Lock Detection & Automatic Restart
Hall Input
Output
TOFF
TON
VLDCL
VLDCP
Motor lock
detected
Motor lock
Motor lock
cleared
Motor restart
FAN8408D features a lock detection and an automatic restart. The functions can be operated as follows.
1) When the hall signal stop switching, a motor can be locked.
2) The voltage, VLD on pin 3, is increasing until it reaches VLDCL.
3) If LD pin is connected to GND, the lockup protection is disabled.
4) While a motor is locked, the output repeats switching ON / OFF, but the other output is always OFF. The switching time can
be determined by an external capacitor on charging / discharging time of the capacitor, switching ON / OFF time can be
calculated as follows.
× (V
– VLDCP )
C
LD
LDCL
T ON = ------------------------------------------------------------------------I
LDC
T
OFF
C
× (V
– VLDCP )
LD
LDCL
= ------------------------------------------------------------------------I
LDD
Where, The CLD is an external capacitor connected to pin 3, LD.
The VLDCL is the clamp voltage on pin 3, LD.
The VLDCP is the comparator voltage on pin 3, LD.
The ILDC is the charging current on pin 3, LD.
The ILDD is the dischaging current on pin 3, LD.
2. Thermal Shut Down
TSD On: All the outputs are off.(Typ. 175°C)
TSD Off: The circuit can be reactivated and begin to operate in a normal condition. (Typ. 150°C)
6
FAN8408D
3. Hall Amplifier Input Block
VCC
R1
C1
IN+
5
FAN8408D
C2
R2
Hall
Sensor
6
IN-
R3
The hall current (IH) is determined by R1, R2 and R3.
V
CC
I H = -----------------------------------R1 + R2 + R3
Where, the R2 is the impedance of hall sensor.
An external capacitor, C1, can be used to reduce a power supply noise. In addition, C2 is to remove a noise which is caused in
case the line is long from the hall sensor output to the hall input (pin 5 / 6) of the device.
The input bias voltage of hall amplifier is between 1V and VCC-2V as following figure.
VCC
VCC-2V
VCC / 2
1V
GND
It is recommended that R1 and R3 should have the same value to make the output signal of hall sensor centered as VCC/2.
7
FAN8408D
Operation Truth Table
IN+
IN-
OUTA
OUTB
HO
High
Low
High
Low
Low
Low
High
Low
High
High
Test Circuits
VCC
1K
50
50
1
OUTB
GND
8
2
HO
OUTA
7
3
LD
IN-
6
4
VCC
IN+
5
ILDC / ILDD
A
VLD
A
ICC
VCC
8
FAN8408D
Typical Application Circuits
LD
3
1
OUTB
2
7
HO
Commutation &
Control
& TSD
OUTA
VCC
VCC
4
IN+
8
GND
5
Hall
6
IN-
Precaution
In case of improper connection (change between power and ground), diode is required to protect motor.
9
FAN8408D
Package Dimensions (Unit: mm)
8-SOP-225
10
FAN8408D
11
FAN8408D
DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY
PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY
LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER
DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES
OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR
CORPORATION. As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body,
or (b) support or sustain life, and (c) whose failure to
perform when properly used in accordance with
instructions for use provided in the labeling, can be
reasonably expected to result in a significant injury of the
user.
2. A critical component in any component of a life support
device or system whose failure to perform can be
reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
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 2002 Fairchild Semiconductor Corporation
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