DC Brushless Fan Motor Driver
5V Single-phase Full-wave
Fan Motor Driver
BU6909AGFT
Description
The BU6909AGFT is a 5V single-phase full-wave FAN motor driver with built in HALL element. It is part of the DC brushless
FAN motor driver series. BU6909AGFT is built in a compact package and provides Auto Gain Control function (AGC), silent
drive by soft switching, and low battery consumption via its standby function. BU6909AGFT is best used for notebook PC
cooling FANs.
Features
Built in HALL element
Auto Gain Control function (AGC)
Soft switching drive (PWM type)
Low PWM duty start up
Quick start function
Stand-by mode
Incorporates lock protection and automatic restart
circuit
Compact package (GFT:TSSOF6 flat lead package)
When TSSOF6 is mounted, package thickness is
0.3mm
Rotating speed pulse signal (FG) output
PWM speed control
Package
TSSOF6
W(Typ) x D(Typ) x H(Max)
2.90mm x 3.80mm x 0.8mm
TSSOF6
Applications
For compact 5V FAN such as notebook PC cooling FAN
Absolute Maximum Ratings
Parameter
Supply Voltage
Power Dissipation
Operating Temperature
Storage Temperature
Output Voltage
Output Current
FG Signal Output Voltage
FG Signal Output Current
Junction Temperature
Symbol
V
CC
Pd
Topr
Tstg
V
OMAX
I
OMAX
V
FG
I
FG
Tjmax
Limit
7
0.54
(Note 1)
-40 to +85
-55 to +125
7
800
(Note 2)
Unit
V
W
°C
°C
V
mA
V
mA
°C
7
10
125
(Note 1) Reduce by 5.4mW/℃ over 25℃. (On 70.0mm×70.0mm×1.6mm glass epoxy board)
(Note 2) This value is not to exceed Pd.
Caution:
Operating the IC over the absolute maximum ratings may damage the IC. The damage can either be a short circuit between pins or an open circuit
between pins and the internal circuitry. Therefore, it is important to consider circuit protection measures, such as adding a fuse, in case the IC is operated
over the absolute maximum ratings.
Recommended Operating Condition
Parameter
Operating Supply Voltage Range
Symbol
V
CC
Limit
1.8 to 5.5
Unit
V
○Product
structure：Silicon monolithic integrated circuit
.
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© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・14・001
○This
product has no protection against radioactive rays
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TSZ02201-0H1H0B101190-1-2
28.Oct.2014 Rev.002
BU6909AGFT
Block Diagram
Datasheet
This is an open drain output.
Connect a pull-up resistor.
Page 15.
HALL ELEMENT
FG
1
OFFSET
CANCEL
OSCILLATOR
CIRCUIT
VCC
A/D
CONVERSION
6
Consider protection against
voltage rise due to reverse
connection of power supply and
back electromotive force.
Page 14.
GND
2
UVLO
TSD
CONTROL
LOGIC
PRE
DRIVER
H-BRIDGE
PWM
Enables speed control by
applying external PWM signal.
Maximum input frequency is
50KHz.
Page 10.
OUT2
4
SIGNAL OUT
5
OUT1
3
LOCK
PROTECTION
PWM DUTY
Conventional FAN motor driver IC with HALL element requires
adjustment of HALL bias resistor due to several factors that
affect the HALL Amplitude. This IC automatically adjusts HALL
amplitude through the use of a built in HALL element and unique
AGC function.
Page 8.
M
(Heat protection circuit)
TSD : Thermal shut down(heat rejection circuit)
UVLO :Under voltage lock outputs (low voltage protection circuit)
Figure 1. Block diagram and Application circuit
Pin Description
Pin No.
1
2
3
4
5
6
Pin Name
FG
GND
OUT1
OUT2
PWM
VCC
GND
Motor output 1
Motor output 2
PWM signal input
Power supply
Function
FG signal output
I/O truth table
・Supply
magnetic direction (positive)
S
Marking
・Output
operation
V
OUT1
B
HYS
B
HYS
B
REV
V
OUT2
N
Magnetic flux density:B
Figure 2. Output operation
B
REV
B
FWD
Magnetic flux density:B
B
FWD
Supply magnetic
direction
S
N
S
N
PWM*
H(OPEN)
H(OPEN)
L
L
OUT1
H
L
L
L
OUT2
L
H
L
L
FG
L (Output Tr：ON)
H (Output Tr：OFF)
H (Output Tr：OFF)
H (Output Tr：OFF)
*When PWM terminal is L, IC state changes to stand-by mode. FG terminal is always H in stand-by mode
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TSZ02201-0H1H0B101190-1-2
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BU6909AGFT
Electrical Characteristics
(Unless otherwise specified Ta=25°C, V
CC
=5V)
Parameter
Circuit Current 1
Circuit Current 2
(stand-by mode)
Magnetic Switch-point for
Forward Rotation
Magnetic Switch-point for
Reverse Rotation
Magnetic hysteresis
PWM Input H Level
PWM Input L Level
PWM Input Frequency
Output Voltage
FG Low Voltage
FG Leak Current
Lock Detection ON Time
Lock Detection OFF Time
Symbol
I
CC
1
I
CC
2
B
FWD
B
REV
B
HYS
V
PWMH
V
PWML
f
PWM
V
O
V
FGL
I
FGL
t
ON
t
OFF
-
2.5
0
5
-
-
-
0.35
3.5
MIN
-
-
-
TYP
2
25
1.5
-1.5
3.0
-
-
-
0.16
-
-
0.50
5.0
-
5.0
V
CC
0.8
50
0.24
0.4
5
0.65
6.5
MAX
4
50
Unit
mA
µA
mT
mT
mT
V
V
kHz
V
V
µA
s
s
Io=200mA
Upper and Lower total
I
FG
=5mA
V
FG
=7V
Conditions
PWM=OPEN
PWM=GND
Datasheet
Characteristics
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
-
-
-
Figure 8 to 13
Figure 14,15
Figure 16
Figure 17
Figure 18
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© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
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TSZ02201-0H1H0B101190-1-2
28.Oct.2014 Rev.002
BU6909AGFT
Typical Performance Curves
4.0
100
Datasheet
Circuit current : I
CC
1 [mA]
Circuit current : I
C C
2 [µA]
3.0
80
2.0
85°C
25°C
-40°C
60
40
85°C
25°C
-40°C
Operating Voltage Range
1.0
20
Operating voltage range
0.0
1
2
3
4
5
Supply voltage : V
CC
[V]
Figure 3. Circuit Current 1
0
6
1
2
3
4
5
Supply Voltage : V
CC
[V]
6
Figure 4. Circuit Current 2 (Stand-by mode)
Magnetic switch-point for forward rotation : B
FWD
[mT]
2.5
2.0
1.5
1.0
0.5
0.0
-0.5
-1.0
-1.5
-2.0
-2.5
1
2
3
4
5
Supply voltage : V
CC
[V]
6
Operating voltage range
Operating Voltage Range
85°C
25°C
-40°C
Magnetic switch-point for reverse rotation : B
REV
[mT]
2.5
2.0
1.5
1.0
0.5
0.0
-0.5
-1.0
-1.5
-2.0
-2.5
1
2
3
4
5
Supply voltage : V
CC
[V]
6
-40°C
25°C
85°C
Operating voltage range
動½電圧範囲
Figure 5. Magnetic Switch-point for Forward Rotation
Figure 6. Magnetic Switch-point for Reverse Rotation
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TSZ02201-0H1H0B101190-1-2
28.Oct.2014 Rev.002
BU6909AGFT
Typical Performance Curves
3.0
Datasheet
- continued
1.0
Magnetic hysteresis : Bhys [mT]
2.5
85℃
25℃
-40℃
0.8
Output H voltage : V
OH
[V]
2.0
0.6
1.5
0.4
1.0
85°C
25°C
-40°C
0.5
0.2
Operating voltage range
0.0
1
2
3
4
5
Supply voltage : Vcc [V]
6
0.0
0.0
0.2
0.4
0.6
Output current : I
O
[A]
0.8
Figure 7. Magnetic hysteresis
Figure 8. Output H Voltage
(Temperature Characteristics)
1.0
1.0
0.8
Output H voltage : V
OH
[V]
Output L voltage : V
OL
[V]
0.8
0.6
1.8V
0.6
85°C
25°C
-40°C
0.4
5.0V
0.4
0.2
5.5V
0.2
0.0
0.0
0.2
0.4
0.6
Output current : I
O
[A]
0.8
0.0
0.0
0.2
0.4
0.6
Output current : I
O
[A]
0.8
Figure 9. Output H Voltage
(Voltage Characteristics)
Figure 10. Output L Voltage
(Temperature Characteristics)
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© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
5/18
TSZ02201-0H1H0B101190-1-2
28.Oct.2014 Rev.002
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