bl0100a ds en

High Efficiency
For LED Backlight, 1ch LED Driver IC
BL0100A
General Descriptions
Package
BL0100A is LED driver IC for LED backlight, and it
can do dimming to 0.02 % by external PWM signal.
This IC realizes a high efficiency by the boost
convertor control that absorbs variability on VF.
The product easily achieves high cost-performance
LED drive system with few external components and
enhanced protection functions.
SOIC14
Not to scale
Features and Benefit
Electrical Characteristics
Boost convertor
● Current-Mode type PWM Control
● PWM frequency is 100 kHz to 500kHz
● Maximum On Duty is 90 %
 Absolute maximum voltage of VCC pin is 20 V
 Adjustable PWM frequency, 100 kHz to 500 kHz
Applications
LED current control
● PWM Dimming
● Analog Dimming
● High contrast ratio is 1 / 5000
● Accuracy of Reg output voltage is ± 2 %
 LED backlights
 LED lighting etc.
Protection functions
● Error Signal Output
● Overcurrent Protection for Boost Circuit (OCP)
------------------------------------------------- Pulse-by-pulse
● Overcurrent Protection for LED Output (LED_OCP)
------------------------------------------------- Pulse-by-pulse
● Overvoltage Protection (OVP) -------------- Auto restart
● Output Open/Short Protection --------------- Auto restart
● Thermal Shutdown (TSD)-------------------- Auto restart
Typical Application Circuit
BL0100A
VCC
VREF
DRV
OC
PWM
ER
OVP
FSET
REG
COMP
SW
IFB
GND
TC_BL0100A_1_R1
BL0100A-DS Rev.1.2
Apr. 04, 2014
SANKEN ELECTRIC CO.,LTD.
1
BL0100A
CONTENTS
General Descriptions ----------------------------------------------------------------------- 1
1. Absolute Maximum Ratings --------------------------------------------------------- 3
2. Electrical characteristics ------------------------------------------------------------- 3
3. Functional Block Diagram ----------------------------------------------------------- 5
4. Pin List Table --------------------------------------------------------------------------- 5
5. Typical Application Circuit --------------------------------------------------------- 6
6. Package Diagram ---------------------------------------------------------------------- 7
7. Marking Diagram --------------------------------------------------------------------- 7
8. Functional Description --------------------------------------------------------------- 8
8.1
Startup Operation ------------------------------------------------------------ 8
8.2
Constant Current Control Operation ------------------------------------ 9
8.3
PWM Dimming Function --------------------------------------------------- 9
8.4
Gate Drive ---------------------------------------------------------------------- 9
8.5
Protection Function --------------------------------------------------------- 10
8.6
Error Signal Output Function -------------------------------------------- 13
9. Design Notes --------------------------------------------------------------------------- 14
9.1
Peripheral Components ---------------------------------------------------- 14
9.2
Inductor Design Parameters----------------------------------------------- 14
9.3
PCD Trace Layout and Component Placement ----------------------- 14
10. Reference Design of Power Supply ----------------------------------------------- 16
OPERATING PRECAUTIONS -------------------------------------------------------- 18
IMPORTANT NOTES ------------------------------------------------------------------- 19
BL0100A-DS Rev.1.2
Apr. 04, 2014
SANKEN ELECTRIC CO.,LTD.
2
BL0100A
1. Absolute Maximum Ratings
 The polarity value for current specifies a sink as "+," and a source as "−," referencing the IC.
 Unless otherwise specified, TA is 25 °C
Parameter
Symbol
Test
Conditions
Pins
Rating
Unit
REG Pin Source Current
IREG
2 −7
−1
mA
OVP Pin Voltage
VOVP
3 −7
− 0 .3 ~5
V
PWM Pin Voltage
VPWM
4 −7
− 0 .3 ~5
V
1 2 −7
− 10
mA
IFB Pin Clamp Current
IFB
S i n gl e
p u l s e 5 µs
FSET Pin Source Current
IFSET
6 −7
− 300
µA
VCC Pin Voltage
VCC
8 −7
− 0 .3 ~2 0
V
SW Pin Voltage
VSW
9 −7
− 0 .3 ~ V C C + 0 .3
V
DRV Pin Voltage
VDRV
1 0 −7
− 0 .3 ~ V C C + 0 .3
V
OC Pin Voltage
VOC
1 1 −7
− 0 .3 ~5
V
ER Pin Voltage
VER
1 4 −7
− 0 .3 ~ V R E G
V
VREF Pin Voltage
VREF
1 −7
− 0 .3 ~5
V
Operating Ambient Temperature
Top
−
− 4 0 ~8 5
°C
Storage Temperature
Tstg
−
− 4 0 ~1 2 5
°C
Junction Temperature
Tj
−
150
°C
2. Electrical characteristics
 The polarity value for current specifies a sink as "+," and a source as "−," referencing the IC.
 Unless otherwise specified, TA is 25 °C, VCC = 12 V
Parameter
Start / Stop Operation
Operation Start Voltage1
Operation Stop Voltage
Circuit Current in Operation
Circuit Current in Non-Operation
REG Pin Output Voltage
Symbol
VCC(ON)
VCC(OFF)
ICC(ON)
ICC(OFF)
VREG
Oscillation
PWM Operation Frequency 1
fPWM1
PWM Operation Frequency 2
fPWM2
Maximum ON Duty
DMAX
Minimum ON Time
tMIN
COMP Pin Voltage at Oscillation
VCOMP(ON)
Start
COMP Pin Voltage at Oscillation
VCOMP(OFF)
Stop
VREF / IFB Pin
VREF Pin Minimum Setting Voltage VREF(MIN)
VREF Pin Maximum Setting Voltage VREF(MAX)
1
Test
Conditions
VCC = 8 V
VFSET = 2 V
R22 = 4.7 kΩ
VREF = 0 V
VREF = 5 V
Pins
Min.
Typ.
Max.
Unit
8 −7
8 −7
8 −7
8 −7
2 −7
8.5
8.0
−
−
4.9
9.6
9.1
5.3
70
5.0
10.5
10.0
8.0
200
5.1
V
V
mA
µA
V
1 0 −7
1 0 −7
1 0 −7
1 0 −7
95
440
85
40
100
500
90
140
105
560
95
240
kHz
kHz
%
ns
1 3 −7
0.35
0.50
0.65
V
1 3 −7
0.10
0.25
0.40
V
1 −7
1 −7
0.05
1.75
0.25
2.00
0.45
2.35
V
V
VCC(ON) > VCC(OFF)
BL0100A-DS Rev.1.2
Apr. 04, 2014
SANKEN ELECTRIC CO.,LTD.
3
BL0100A
Parameter
Symbol
IFB Pin Voltage at Auto Restart
VIFB(AR)
Operation
IFB Pin Voltage at COMP Charge
VIFB(COMP)
Switching
IFB Pin Overcurrent Protection Low
VIFB(OCL)
Threshold Voltage
IFB Pin Overcurrent Protection
VIFB(OCL-OFF)
Release Threshold Voltage
IFB Pin Overcurrent Protection High
VIFB(OCH)
Threshold Voltage
IFB Pin Bias Current
IIFB(B)
Current Detection Threshold Voltage
VIFB
COMP Pin
COMP Pin Maximum Output
VCOMP(MAX)
Voltage
COMP Pin Minimum Output Voltage VCOMP(MIN)
Transconductance
gm
COMP Pin Source Current
ICOMP(SRC)
COMP Pin Sink Current
ICOMP(SNK)
COMP Pin Charge Current at Startup
ICOMP(S)
COMP Pin Reset Current
ICOMP(R)
ER Pin
ER Pin Sink Current during
IER
Non-Alarm
Boost Parts Overcurrent Protection (OCP)
OC Pin Overcurrent Protection
VOCP
Threshold Voltage
Overvoltage Protection (OVP)
OVP Pin Overvoltage Protection
VOVP
Threshold Voltage
OVP Pin OVP Release Threshold
VOVP(OFF)
Voltage
PWM Pin
PWM Pin ON Threshold Voltage
VPWM(ON)
PWM Pin OFF Threshold Voltage
VPWM(OFF)
PWM Pin Impedance
RPWM
SW / DRV Pin
SW Pin Source Current
ISW(SRC)
SW Pin Sink Current
ISW(SNK)
DRV Pin Source Current
IDRV(SRC)
DRV Pin Sink Current
IDRV(SNK)
Thermal Shutdown Protection (TSD)
Thermal Shutdown Activating
Tj(TSD)
Temperature
Hysteresis Temperature of TSD
Tj(TSD)HYS
Thermal Resistance
Thermal Resistance from Junction to
θj-A
Ambient
BL0100A-DS Rev.1.2
Apr. 04, 2014
Test
Conditions
Pins
Min.
Typ.
Max.
Unit
VREF = 1 V
1 2 −7
0.45
0.50
0.55
V
VREF = 1 V
1 2 −7
0.55
0.60
0.65
V
VREF = 1 V
1 2 −7
1.9
2.0
2.1
V
VREF = 1 V
1 2 −7
1.5
1.6
1.7
V
1 2 −7
3.8
4.0
4.2
V
VREF = 1 V
1 2 −7
1 2 −7
−
0.98
−
1.00
1
1.02
µA
V
VIFB = 0.7 V
1 3 −7
4.8
5.0
−
V
VIFB = 2.0 V
1 3 −7
−
1 3 −7
1 3 −7
1 3 −7
1 3 −7
−
−
− 77
37
− 19
200
0
640
− 57
57
− 11
360
0.2
−
− 37
77
−3
520
V
µS
µA
µA
µA
µA
VER = 1 V
1 4 −7
2.5
4.4
6.3
mA
VCOMP = 4.5 V
1 1 −7
0.57
0.60
0.63
V
3 −7
2.85
3.00
3.15
V
3 −7
2.60
2.75
2.90
V
4 −7
4 −7
4 −7
1.4
0.9
100
1.5
1.0
200
1.6
1.1
300
V
V
kΩ
9 −7
9 −7
1 0 −7
1 0 −7
−
−
−
−
− 85
220
− 0.36
0.85
−
−
−
−
mA
mA
A
A
−
125
−
−
°C
−
−
65
−
°C
−
−
−
120
°C/W
VIFB = 5 V
VIFB = 0.7 V
VIFB = 1.5 V
VCOMP = 0 V
SANKEN ELECTRIC CO.,LTD.
4
BL0100A
3. Functional Block Diagram
VCC
8
2
REG
9
SW
10
DRV
14
ER
11
OC
7
GND
VCC UVLO
REG ON/OFF
PWM
PWM Pulse
Detector
4
TSD
VCC
Drive
FSET
6
OVP
3
Overvoltage
Detector
VREF
1
Abnormal
Detector
PWM OSC
Main Logic
VCC
Drive
Auto Restart
Protection
OC Control
FB
Feedback
Control
12
Slope
Compensation
13
COMP
BD_BL0100A_R1
4. Pin List Table
Number
Name
Function
1
VREF
Detection voltage setting
2
REG
Internal regulator output
3
OVP
Overvoltage detection signal input
VREF
1
14
ER
REG
2
13
COMP
OVP
3
12
IFB
4
PWM
Dimming MOSFET gate drive output
PWM
4
11
OC
5
(N.C.)
-
(N.C.)
5
10
DRV
6
FSET
Boost MOSFET drive frequency setting
FSET
6
9
SW
7
GND
Ground
GND
7
8
VCC
8
VCC
Power supply voltage input
9
SW
PWM dimming drive output
10
DRV
11
OC
12
IFB
Boost MOSFET gate drive output
Current mode control signal input and
overcurrent protection signal input
Feedback signal input of current detection
13
COMP
Phase compensation and soft-start setting
14
ER
BL0100A-DS Rev.1.2
Apr. 04, 2014
Error signal output
SANKEN ELECTRIC CO.,LTD.
5
BL0100A
5. Typical Application Circuit
L1
F1
D1
LED_OUT(+)
P_IN
LED_OUT(−)
R6
R2
R9
C2
Q1
C1
D2
R1
Q2
D3
R3
R7
R4
R8
R10
R11
P_GND
ER_OUT
R5
R17
C5
U1
VREF
PWM_IN
C6
REG
C7
OVP
PWM
Q3
VCC_IN
C8
R13
(N.C.)
FSET
R14
C3
R16
ON/OFF
Q4
C4
R15
R22
R21
GND
1
14
2
13
3
4
5
BL0100A
R18
R20
R12
12
11
10
6
9
7
8
ER
COMP
IFB
OC
DRV
SW
VCC
R23
R19
C11
C9
C12
C13
C10
S_GND
TC_BL0100A_2_R1
Figure 5-1 Typical Application Circuit
BL0100A-DS Rev.1.2
Apr. 04, 2014
SANKEN ELECTRIC CO.,LTD.
6
BL0100A
6. Package Diagram
6.0
3.9
0.25
 SOIC14
0.6
1.45
8.65
0.15
1.27
NOTES:
1) Dimension is in millimeters
2) Pb-free. Device composition compliant with the RoHS directive
0.43
7. Marking Diagram
14
B L 0 1 0 0 A
Part Number
S K Y M D
1
Lot Number
Y is the last digit of the year (0 to 9)
M is the month (1 to 9, O, N or D)
D is a period of days (1 to 3) :
1 : 1st to 10th
2 : 11th to 20th
3 : 21st to 31st
Sanken Control Number
BL0100A-DS Rev.1.2
Apr. 04, 2014
SANKEN ELECTRIC CO.,LTD.
7
BL0100A
8.
 All
Functional Description
of the parameter values used in these
descriptions are typical values, unless they are
specified as minimum or maximum.
 With regard to current direction, "+" indicates sink
current (toward the IC) and "–" indicates source
current (from the IC).
When the on-duty of the PWM dimming signal is
small, the charge current at the COMP pin is controlled
as follows in order to raise the output current quickly at
startup.
Figure 8-3 shows the operation waveform with the
PWM dimming signal at startup.
VCC pin voltage
8.1 Startup Operation
VCC(ON)
Figure 8-1 shows the VCC pin peripheral circuit. The
VCC pin is the power supply input for control circuit
from the external power supply.
When the VCC pin voltage increases to the Operation
Start Voltage, VCC(ON) = 9.6 V, the control circuit starts
operation. After that, when the PWM pin voltage exceeds
the PWM Pin ON Threshold Voltage, VPWM(ON) of 1.5 V
(less than absolute maximum voltage of 5 V), the COMP
Pin Charge Current at Startup, ICOMP(S) = −11 µA, flows
from the COMP pin. This charge current flows to
capacitors at the COMP pin. When the COMP pin
voltage increases to the COMP Pin Voltage at Oscillation
Start, VCOMP(ON) = 0.50 V or more, the control circuit
starts switching operation.
As shown in Figure 8-2, when the VCC pin voltage
decreases to the Operation Stop Voltage, VCC(OFF) = 9.1 V,
the control circuit stops operation, by the UVLO
(Undervoltage Lockout) circuit, and reverts to the state
before startup.
External power supply
8
PWM
VCC
U1
VREF pin voltage
VIFB(COMP.VR)
0
PWM pin
Dimming signal
0
COMP pin
charge current
0
ICOMP(S)
ICOMP(SRC)
COMP pin
voltage
VCOMP(ON)
0
IC switching
status OFF
ON
GND
13
7
C9
R23
C11
Constant current control
IFB pin voltage
Figure 8-3 Startup operation during PWM dimming
COMP
C3
4
0
C10
Figure 8-1 VCC pin peripheral circuit
ICC
ICC(ON)
While the IFB pin voltage increases to the IFB Pin
Voltage at COMP Charge Switching, VIFB(COMP.VR), a
capacitors at the COMP pin are charged by ICOMP(S) = –11
µA. During this period, they are charged by the COMP
Pin Source Current, ICOMP(SRC) = –57 µA, when the PWM
pin voltage is 1.5 V or more. Thus, the COMP pin
voltage increases immediately. When the IFB pin voltage
increases to VIFB(CMP1.VR) or more, the COMP pin source
current is controlled according to the feedback amount,
and the output current is controlled to be constant. The
VCC(OFF)
Start
Stop
on-duty gradually becomes wide according to the
increase of the COMP pin voltage, and the output
power increases (Soft start operation). Thus, power
stresses on components are reduced.
VCC(ON)
Figure 8-2 VCC versus ICC
BL0100A-DS Rev.1.2
Apr. 04, 2014
VCC
When the VCC pin voltage decreases to the operation
stop voltage or less, or the Auto Restart operation (see
the Section 8.5 Protection Function) after protection is
achieved, then the control circuit stops switching
operation, and capacitors at the COMP pin are
discharged by the COMP Pin Reset Current,
ICOMP(R) = 360 µA, simultaneously. The soft start
operation is achieved at restart.
The IC is operated by Auto Restart 1 at startup
SANKEN ELECTRIC CO.,LTD.
8
BL0100A
operation. See the Section 8.5 Protection Function about
the caution of startup operation.
VIFB(COMP.VR) is determined by the VREF pin voltage,
as shown in Figure 8-4. When VREF pin voltage is 1V,
the value of VIFB(COMP.VR) becomes 0.60 V.
VIFB(COMP.VR)
1.2V
0.6V
0.15V
0.25V
1V
2V
VREF pin voltage
8.3 PWM Dimming Function
Figure 8-6 shows the peripheral circuit of PWM pin
and SW pin. The PWM pin is used for the PWM
dimming signal input. The SW pin drives the gate of
external MOSFET, Q2. The SW pin voltage is turned on
/ off by PWM signal, and thus the dimming of LED is
controlled by PWM signal input.
As shown in Figure 8-7, when the PWM pin voltage
becomes the PWM Pin ON Threshold Voltage,
VPWM(ON) = 1.5 V or more, the SW pin voltage becomes
VCC. When the PWM pin voltage becomes the PWM Pin
OFF Threshold Voltage, VPWM(OFF) = 1.0 V or less, the
SW pin voltage becomes 0.1 V or less. The PWM pin has
the absolute maximum voltage of −0.3 V to 5.0 V, and
the input impedance, RPWM, of 200 kΩ. The PWM
dimming signal should meet these specifications and
threshold voltages of VPWM(ON) and VPWM(OFF).
Figure 8-4 VREF pin voltage versus IFB pin voltage at
COMP charge switching
LED_OUT (+)
4
U1
PWM
8.2 Constant Current Control Operation
Figure 8-5 shows the IFB pin peripheral circuit.
When Q2 turns on, the LED output current, IOUT(CC), is
detected by the current detection resistor, R11. The IC
compares the IFB pin voltage with the VREF pin voltage
by the internal error amplifier, and controls the IFB pin
voltage so that it gets close to the VREF pin voltage.
The reference voltage at the VREF pin is the divided
voltage of the REG pin voltage, VREG = 5 V, by R20 and
R21, and thus this voltage can be externally adjusted.
The setting current, IOUT(CC), of the LED_OUT can be
calculated as follows.
I OUT ( CC) 
VREF
R SEN
(8-1)
U1
VCC
PWM Pulse
Detector
REG
PWM OSC
Main Logic
SW
9
Q2
Figure 8-6 The peripheral circuit of PWM pin
and SW pin.
PWM pin voltage
VPWM(OFF)
0
Time
SW pin voltage
VCC
≤ 0.1V
5V
2
0
R20
IOUT(CC)
Time
Figure 8-7 The waveform of PWM pin and SW pin
VREF 1
LED_OUT(-)
R21
Abnormal
Detector
Drive
R11
LED_OUT(+)
Error Amp.
LED_OUT (−)
VCC
VPWM(ON)
where:
VREF is the VREF pin voltage.
The value is recommended to be 0.5 V to 2.0 V.
RESN is the value of R11
8
LED
PWM_IN
Q2
IFB 12
R11
Output current detection resistor
Figure 8-5 IFB pin peripheral circuit
BL0100A-DS Rev.1.2
Apr. 04, 2014
8.4 Gate Drive
Figure 8-8 shows the peripheral circuit of DRV pin
and SW pin and FSET pin. The DRV pin is for boost
MOSFET, Q1. The SW pin is for dimming MOSFET,
Q2. Table 8-1 shows drive voltages and currents of DRV
pin and SW pin.
● Q1 and Q2 should be selected so that these VGS(th)
threshold voltages are less than VCC enough over entire
operating temperature range.
SANKEN ELECTRIC CO.,LTD.
9
BL0100A
● Peripheral components of Q1 (R1, R2, and D2) and Q2
(R8, R9, and D3) affect losses of power MOSFET,
gate waveform (ringing caused by the printed circuit
board trace layout), EMI noise, and so forth, these
values should be adjusted based on actual operation in
the application.
● R3 for Q1 and R10 for Q2 are used to prevent
malfunctions due to steep dv/dt at turn-off of the
power MOSFET, and these resistors are connected
near each the gate of the power MOSFETs and the
ground line side of the current detection resistance.
The reference value of them is from 10 kΩ to 100 kΩ.
D1
LED_OUT(+)
L1
C1
C2
Q1
R2
R9
D2
R4
R1
FSET
6
R3
VCC
U1
R22
D3
R8
Overcurrent of boost circuit (OCP)
2
Overcurrent of LED output (LED_OCP)
3
Overvoltage of LED_OUT(+) (OVP)
4
Short mode between LED_OUT(−) and GND
Short mode of LED current detection resistor
(RSEN_Short)
Short mode of both ends of LED output
Open mode of LED current detection resistor
(RSEN_Open)
8
Overtemperature of junction of IC (TSD)
VCC
9
GND
7
Drive current, IDRV
Source
Sink
–0.36 A
0.85 A
–85 mA
220 mA
600
500
400
300
200
100
0
1
10
100
1000
RFSET (kΩ)
Figure 8-9 Relation between PWM oscillation frequency
and RFSET
BL0100A-DS Rev.1.2
Apr. 04, 2014
Protection
Operations
Auto
Restart 1
Auto
Restart 2
Auto
Restart 3
SW
As shown in Figure 8-9, the PWM oscillation
frequency of DRV pin can be set between 100 kHz and
500 kHz, depending on the value of R22 connected to
FSET pin, RFSET.
PWM oscillation frequency
of DRV pin (kHz)
1
Drive
PWM OSC
Main Logoc
Drive voltage, VDRV
High
Low
0.1V
VCC
or less
0.1V
VCC
or less
SW
Abnormal States
7
Table 8-1 Drive voltage and current
DRV
Table 8-2 Relationship between a kind of abnormal state
and protection operations
6
Figure 8-8 The peripheral circuit of DRV pin,
SW pin and FSET pin
Pins
As shown in Table 8-2, the IC performs protection
operations according to kind of abnormal state. In all
protection functions, when the fault condition is removed,
the IC returns to normal operation automatically. The
intermitted oscillation operation reduces stress on the
power MOSFET, the secondary rectifier diode, and so
forth.
5
R10 R11
10
DRV
Drive
C8
Q2
8.5 Protection Function
Auto Restart 1:
As shown in Figure 8-10, the IC repeats an intermitted
oscillation operation, after the detection of any one of
abnormal states 1 to 5 in Table 8-2. This intermitted
oscillation is determined by tARS1 or tARS2, and tAROFF1.
The tARS1 is an oscillation time in the first intermitted
oscillation cycle, TAR1. The tARS2 is an oscillation time in
the second and subsequent intermitted oscillation cycle,
TAR2. The tAROFF1 is a non-oscillation time in all
intermitted oscillation cycle.
In case PWM dimming frequency is low and the
on-duty is small, the startup operation, the restart
operation from on-duty = 0 % and the restart operation
from intermitted oscillation operation need a long time.
Thus the value of tARS1 and tARS2 depend on frequency
and on-duty of the PWM dimming signal, as shown in
Figure 8-12 and Figure 8-13.
In case the on-duty is 100 %, the value of t ARS1 is 61.4
ms, and tARS2 is 41.0 ms. The value of tAROFF1 is about
1.3 s.
Auto Restart 2:
As shown in Figure 8-11, the IC stops the switching
operation immediately after the detection of abnormal
states 6 or 7 in Table 8-2, and repeats an intermitted
oscillation operation. In the intermitted oscillation cycle,
the tARSW is an oscillation time, the tAROFF1 is a
non-oscillation time.
The value of tARSW is a few microseconds. The value of
tARS2 is derived from Figure 8-11, and tAROFF2 is
calculated as follows:
t AROFF 2  t ARS 2  t ARSW  t AROFF 1
SANKEN ELECTRIC CO.,LTD.
(8-2)
10
BL0100A
In case the on-duty is 100%, the value of tAROFF2
becomes about 1.341 ms.
The operating condition of Auto Restart 1 and 2 is as
follows:
Auto Restart 3:
The IC stops the switching operation immediately after
the detection of abnormal states 8 in Table 8-2, and
keeps a non-oscillation.
< The operating condition of Auto Restart 1 >
The Auto Restart 1 is operated by the detection signals
of the OC pin or IFB pin.
Release
Abnormal
state
SW pin
voltage
tARS1
tARS2
Return to
normal
operation
tARS2
0
tAROFF1
TAR1
tAROFF1
tAROFF1
TAR2
TAR2
Time
● Operation by the detection signal of OC pin:
When the OC pin voltage increase to the OC Pin
Overcurrent
Protection
Threshold
Voltage,
VOCP = 0.60 V, or more, the operation of the IC
switches to Auto Restart 1. When the fault condition is
removed and the OC pin voltage decreases to under
VOCP, the IC returns to normal operation automatically.
● Operation by the detection signal of IFB pin:
As shown in Figure 8-14, IFB pin has two types of
threshold voltage. These threshold voltages depend on
the VREF pin voltage, as shown in Figure 8-15.
Figure 8-10 Auto Restart 1
IFB pin
voltage
Release
VIFB(OCL.VR)
Abnormal
state
tARSW
SW pin
voltage
tAROFF2
Return to
normal
operation
tARSW
tAROFF2
tAROFF2
tARS2
tARS2
tAROFF1
0
Return to normal operation
SW pin
voltage
Time
Time
Auto Restart 1
fDM : PWM dimming frequency
2500
Figure 8-14 IFB pin threshold voltage
and Auto Restart 1 operation
fDM = 100 Hz
fDM = 300 Hz
2000
1500
VIFB(OCL.VR) : IFB Pin Overcurrent Protection Low Threshold Voltage
VIFB(OCL-OFF.VR) :IFB Pin Overcurrent Protection Release Threshold Voltage
VIFB(AR.VR) :IFB Pin Auto Restart Operation Threshold Voltage
1000
500
10.0
0
0.1
1
Duty (%)
10
Figure 8-12 PWM dimming on-duty versus tARS1
fDM : PWM dimming frequency
1400
1200
fDM = 100 Hz
fDM = 300 Hz
1000
VIFB(OCL.VR)
4.0V
3.2V
VIFB(OCL.VR)
100
800
IFB pin threshold voltages (V)
0.01
tARS2 (ms)
Time
0
tAROFF1
Figure 8-11 Auto Restart 2
tARS1 (ms)
VIFB(COMP)
VIFB(AR.VR)
0
tAROFF1
VIFB(OCL-OFF.VR)
VIFB(AR.VR)
1.0V
1.0
0.5V
0.4V
600
400
0.125V
0.1
0.1
200
0.25V
0
0.01
0.1
1
Duty (%)
10
100
Figure 8-13 PWM dimming on-duty versus tARS2
BL0100A-DS Rev.1.2
Apr. 04, 2014
1.0
VREF pin voltage (V)
Figure 8-15 VREF pin voltage versus
IFB pin threshold voltages
SANKEN ELECTRIC CO.,LTD.
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BL0100A
1) In case IFB pin voltage increased
When the FB pin voltage increase to VIFB(OCL.VR) in
Figure 8-15, or more, the operation of the IC switches
to Auto Restart 1. When the fault condition is
removed and the IFB pin voltage decreases to
VIFB(OCL-OFF.VR) in Figure 8-15, or less, the IC returns
to normal operation automatically.
2) In case IFB pin voltage decreased
When the FB pin voltage decrease to VIFB(AR.VR) in
Figure 8-15, or more, the operation of the IC switches
to Auto Restart 1. When the fault condition is
removed and the IFB pin voltage increases to above
VIFB(COMP), the IC returns to normal operation
automatically.
< The operating condition of Auto Restart 2 >
The Auto Restart 2 is operated by the detection signal
of the IFB pin.
As shown in Figure 8-16, when the FB pin voltage
increase to the IFB Pin Overcurrent Protection High
Threshold Voltage, VIFB(OCH) = 4.0 V, or more, the
operation of the IC switches to Auto Restart 2, and the IC
stops switching operation immediately. When the fault
condition is removed and the IFB pin voltage decreases
to under VIFB(OCH), the operation of the IC switches to
Auto Restart 1.
The protection operation according to the abnormal states
in Table 8-2 is described in detail as follows:
8.5.1 Overcurrent of Boost Converter Part
(OCP)
When the OC pin detects the overcurrent of boost
circuit, the IC switches to Auto Restart 1.
Figure 8-17 shows the peripheral circuit of OC pin.
When Q1 turns on, the current flowing to L1 is detected
by R4, and the voltage on R4 is input to the OC pin.
When the OC pin voltage increases to the OC Pin
Overcurrent Protection Threshold Voltage, VOCP = 0.60
V or more, the on-duty becomes narrow by
pulse-by-pulse basis, and the output power is limited.
L1
LED_OUT(+)
D1
IL(ON)
LED_OUT(-)
Q1
R4
U1
OC
C2
R5
Q2
R11
11
C12
GND 7
IFB pin
voltage
VIFB(OCH)
Figure 8-17 OC pin peripheral circuit
VIFB(OCL-OFF.VR)
0
Return to normal
operation
SW pin
voltage
0
Time
Auto Restart 2
Auto Restart 1
Figure 8-16 IFB pin threshold voltage
and Auto Restart 2 operation
< Caution of startup operation >
When the LED current is low and the IFB pin voltage
is less than VIFB(AR.BR), during startup for example, the IC
is operated by Auto Restart 1. If the startup time is too
long, the IC operation becomes the intermitted oscillation
by the Auto Restart 1. It becomes cause of the fault
startup operation, thus the startup time should be set less
than tARS1 in Figure 8-10.
8.5.2 Overcurrent of LED Output
(LED_OCP)
Figure 8-18 shows the peripheral circuit of IFB pin
and COMP pin.
When Q2 turns on, the output current is detected by
R11. When the boost operation cannot be done by failure
such as short circuits in LED string, the IFB pin voltage
is increased by the increase of LED current. There are
three types of operation modes in LED_OCP state.
(1) When the IFB pin voltage is increased by the increase
of LED current, COMP pin voltage is decreases. In
addition, when the COMP pin voltage decreases to
the COMP Pin Voltage at Oscillation Stop,
VCOMP(OFF) = 0.25 V or less, the IC stops switching
operation, and limits the increase of the output
current.
When IFB pin voltage is decreased by the decrease of
LED current, COMP pin voltage increases. When
COMP pin voltage becomes VCOMP(ON) = 0.50 V or
more, the IC restarts switching operation.
(2) When IFB pin voltage becomes VIFB(OCL.VR) or more
(see Figure 8-15), the IC switches to Auto Restart 1.
(3) The LED current increases further and when the IFB
pin voltage increases to the IFB Pin Overcurrent
Protection High Threshold Voltage, VIFB(OCH) = 4.0 V
or more, the IC switches to Auto Restart 2.
BL0100A-DS Rev.1.2
Apr. 04, 2014
SANKEN ELECTRIC CO.,LTD.
12
BL0100A
LED_OUT(+)
U1
IFB 12
Feedback
control
When the output current detection resistor, R11, is
shorted, the IFB pin voltage decreases. When the IFB pin
voltage decreases to VIFB(AR.VR) in Figure 8-15, then the
IC switches to Auto Restart 1.
LED_OUT(-)
COMP 13
8.5.6 Short Mode of LED Output Both Ends
R23 C11
OC control
C10
Q2
R11
Output current detection resistor
Figure 8-18 The peripheral circuit of IFB pin
and COMP pin
8.5.3 Overvoltage of LED_OUT (+) (OVP)
Figure 8-19 shows OVP pin peripheral circuit.
The OVP pin detects the divided LED output voltage
by R6 and R7. When the LED_OUT (+) or the IFB pin is
open and the OVP pin voltage increases to the OVP Pin
Overvoltage Protection Threshold Voltage, VOVP = 3.00
V, the IC immediately stops switching operation. When
the OVP pin voltage decreases to the OVP Pin
Overvoltage Protection Release Threshold Voltage,
VOVP(OFF) = 2.75 V or the IFB pin voltage decreases to
VIFB(AR.VR) in Figure 8-15, then the IC switches to Auto
Restart 1.
L1
8.5.5 Short Mode of LED Current Detection
Resistor (RSEN_Short)
When the LED_OUT (+) and LED_OUT (–) are
shorted, the short current flows through the detection
resistor (R11) while Q2 turns on. The IFB pin detects the
voltage rise of the detection resistor. When the IFB pin
voltage increases to the IFB Pin Overcurrent Protection
High Threshold Voltage, VIFB(OCH) = 4.0 V or more, the
IC switches to Auto Restart 2.
8.5.7 Open Mode of LED Current Detection
Resistor (RSEN_Open)
When the output current detection resistor, R11, is
open, the IFB pin voltage increases. When the IFB pin
voltage increases to the IFB Pin Overcurrent Protection
High Threshold Voltage, VIFB(OCH) = 4.0 V or more, the
IC switches to Auto Restart 2.
8.5.8 Overtemperature of junction of IC
(TSD)
LED_OUT(+)
When the temperature of the IC increases to
Tj(TSD) = 125 °C (min) or more, the TSD is activated, and
the IC stops switching operation. When the junction
temperature decreases by Tj(TSD) − Tj(TSD)HYS after the fault
condition is removed, the IC returns to normal operation
automatically.
LED_OUT(-)
8.6 Error Signal Output Function
D1
R6
Q1
Q2
C2
R4
R7
R11
OVP 3
U1
When an external circuit such as microcomputer uses
the error signal output, configure the peripheral circuit of
ER pin using the pull-up resistor, R8, and the protection
resistor of ER pin, RER, as shown in Figure 8-20.
The ER pin is connected to internal switch. When the
protection function is active, the internal switch becomes
OFF and ER_OUT becomes REG pin voltage from 0 V.
The resistances of R17 and RER are about 10 kΩ.
C7
GND 7
REG
2
R17
ER
Figure 8-19 OVP pin peripheral circuit
8.5.4 Short Mode between LED_OUT(−)
and GND
When the LED_OUT (–) and the GND are shorted,
and the IFB pin voltage decreases to VIFB(AR.VR) in Figure
8-15, then the IC switches to Auto Restart 1.
BL0100A-DS Rev.1.2
Apr. 04, 2014
Auto restart
protection
GND
7
ER_OUT
14
RER
C6
Figure 8-20 ER pin peripheral circuit
SANKEN ELECTRIC CO.,LTD.
13
BL0100A
9.
depends on the value of R22 connected to FSET pin.
The value of fPWM is set by Figure 8-9.
Design Notes
9.1 Peripheral Components
Take care to use the proper rating and proper type of
components.
 Input and output electrolytic capacitors, C1 and C2
▫ Apply proper design margin to accommodate ripple
current, voltage, and temperature rise.
▫ Use of high ripple current and low impedance types,
designed for switch-mode power supplies, is
recommended, depending on their purposes.
 Inductor,L1
▫ Apply proper design margin to temperature rise by
core loss and copper loss.
▫ Apply proper design margin to core saturation
 Current detection resistors, R4 and R11
Choose a type of low internal inductance because a
high frequency switching current flows to the current
detection resistor, and of properly allowable
dissipation.
(3) Inductance value, L
The inductance value, L, for DCM or CRM mode can
be calculated as follow:
L
VIN  DON 2
2  I OUT  f PWM  VO UT  VIN 
(9-2)
where:
IOUT is the maximum output current,
fPWM is the maximum operation frequency of PWM
(4) Peak inductor current, ILP
I LP 
VIN  D ON
L  f PWM
(9-3)
(5) Inductor selection
The inductor should be applied the value of
inductance, L, from equation (9-2) and the DC
superimposition characteristics being higher than the
peak inductor current, ILP, from equation (9-3).
9.2 Inductor Design Parameters
The CRM* or DCM* mode of boost converter with
PWM dimming can improve the output current rise
during PWM dimming.
* CRM is the critical conduction mode,
DCM is the discontinuous conduction mode.
The CRM or DCM inductor design procedure is
described as follow:
(1) On-duty Setting
The output voltage of boost converter is more than
the input voltage. The on-duty, DON can be calculated
using following equation. The equality of the
equation means the condition of CRM mode
operation and the inequality means that of DCM
mode operation.
D ON 
VOUT  VIN
VOUT
Since the PCB circuit trace design and the component
layout significantly affects operation, EMI noise, and
power dissipation, the high frequency PCB trace as shown
in Figure 9-1 should be low impedance with small loop
and wide trace.
L1
C1
Figure 9-1
DON is selected by the above equation applied to
CRM or DCM mode. In case fPWM = 100 kHz, the
range of DON should be 1.4 % to 90 %. In case
fPWM = 500 kHz, the range of DON should be 7 % to
90 %. (The minimum value results from the condition
of tMIN = 140 ns, and fPWM. The maximum value is
DMAX).
(2) PWM oscillation frequency selection
The PWM oscillation frequency of DRV pin, fPWM,
D1
Q1
(9-1)
where:
VIN is the minimum input voltage,
VOUT is the maximum forward voltage drop of LED
string.
BL0100A-DS Rev.1.2
Apr. 04, 2014
9.3 PCD Trace Layout and Component
Placement
C2
High-frequency current loops
(hatched areas)
In addition, the ground traces affect radiated EMI noise,
and wide, short traces should be taken into account.
Figure 9-2 shows the circuit design example.
(1) Main Circuit Trace Layout
This is the main trace containing switching currents,
and thus it should be as wide trace and small loop as
possible.
C1 should be connected near the inductors, L1, in
order to reduce impedance of the high frequency
current loop.
(2) Control Ground Trace Layout
Since the operation of IC may be affected from the
large current of the main trace that flows in control
ground trace, the control ground trace should be
SANKEN ELECTRIC CO.,LTD.
14
BL0100A
connected at a single point grounding of point A with
a dedicated trace.
(5) Bypass Capacitor Trace Layout on VCC , REG, and
VREF pins
C9, C6 and C5 of bypass capacitors, connected to
VCC, REG, and VREF pins respectively, should be
connected as close as possible to the pin of IC
(3) Current Detection Resistor Trace Layout
R4 and R11 are current detection resistors.
The trace from the base of current detection resistor
should be connected to the pin of IC with a dedicated
trace.
(6) Power MOSFET Gate Trace Layout
R3 for Q1 and R10 for Q2 should be connected near
each the gate of the power MOSFETs and the ground
line side of the current detection resistance.
Peripheral components of Q1 (R1, R2, and D2) and
Q2 (R8, R9, and D3) should be connected as close as
possible between each the gate of the power
MOSFETs and the pin of IC.
(4) COMP pin Trace Layout for Compensation
Component
R23, C10 and C11 are compensation components.
The trace of the compensation component should be
connected as close as possible to the pin of IC, to
reduce the influence of noise.
(6) Power MOSFET Gate Trace Layout
R3(R10) should be connected near gate of Q1(Q2) and ground line side of R4(R11).
R1,R2 and D2 (R8, R9 and D3) should be connected as close as possible between gate of
Q1(Q2) and DRV(SW) pin.
(1) Main circuit trace Should be
as wide trace and small loop.
F1
LED_OUT(+)
P_IN
L1
D1
LED_OUT(−)
R6
R2
R9
C2
Q1
C1
D2 R3
D3
R1
A
(2) Control ground trace layout should be
connected at a single point grounding of
point A with a dedicated trace
R7
R4
R8
Q2
R10
R11
P_GND
ER_OUT
R5
R17
C5
U1
VREF
PWM_IN
C6
REG
OVP
C7
Q3
VCC_IN
PWM
C8
R13
(N.C.)
FSET
R14
ON/OFF
R22
C3
R16
GND
1
14
2
13
3
4
5
BL0100A
R18
R20
12
11
10
6
9
7
8
Q4
C4
R15
R21
R19
R12
C9
ER
COMP
IFB
OC
(3) Current detection trace should
be connected to the pin of IC
with a dedicated trace.
DRV
SW
VCC
R23
C10
C11
C12
C13
S_GND
(5)Bypass capacitor(C5,C6,C8)should be Connected as
close as possible to the pin of IC.
(4) COMP pin peripheral components should be
connected as close as possible to the pin of IC.
Figure 9-2 Peripheral circuit example around the IC
BL0100A-DS Rev.1.2
Apr. 04, 2014
SANKEN ELECTRIC CO.,LTD.
15
BL0100A
10. Reference Design of Power Supply
As an example, the following show a power supply specification, circuit schematic, bill of materials, and
transformer specification.
This reference design is the example of the value of parts, and should be adjusted based on actual operation in the
application.
 Power Supply Specification
IC
Input voltage
Maximum output power
DRV pin oscillation frequency
Output voltage
Output current
BL0100A
DC 24 V
20 W (max.)
100 kHz
50 V
400 mA
 Circuit Schematic
L1
F1
D1
LED_OUT(+)
P_IN
LED_OUT(−)
R6
R2
C2
Q1
C1
R9
D2
R1
Q2
D3
R3
R7
R4
R8
R10
R11
P_GND
ER_OUT
R5
R17
R12
R18
R23
C5
R19
U1
VREF
PWM_IN
C6
REG
C7
OVP
PWM
Q3
VCC_IN
C8
R13
(N.C.)
FSET
R14
C3
R16
ON/OFF
Q4
C4
R15
R24
R22
R20
GND
1
14
2
13
3
4
5
BL0100A
R21
12
11
10
6
9
7
8
ER
COMP
IFB
OC
DRV
SW
VCC
R25
C11
C9
C12
C13
C10
S_GND
TC_BL0100A_3_R1
BL0100A-DS Rev.1.2
Apr. 04, 2014
SANKEN ELECTRIC CO.,LTD.
16
BL0100A
 Bill of Materials
Symbol
Part type
F1
L1
D1
D2
D3
Fuse
Inductor
Fast recovery
Schottky
Schottky
Q1
Power MOSFET
Q2
Power MOSFET
Q3
Q4
C1
C2
C3
C4
C5
C6
C7
C8
C9
C10
C11
C12
C13
R1
R2
PNP Transistor
NPN Transistor
Electrolytic
Electrolytic
Electrolytic
Ceramic, chip, 2012
Ceramic, chip, 2012
Ceramic, chip, 2012
Ceramic, chip, 2012
Ceramic, chip, 2012
Ceramic, chip, 2012
Ceramic, chip, 2012
Ceramic, chip, 2012
Ceramic, chip, 2012
Ceramic, chip, 2012
General, chip, 2012
General, chip, 2012
(2)
(2)
(2)
Ratings(1)
3A
50 μH, 3 A
200 V, 1.5 A
30 V, 1 A
30 V, 1 A
200 V,
45 mΩ (typ.)
100 V,
1 Ω (typ.)
−50 V, 0.1 A
50 V, 0.1 A
50 V, 22 μF
100 V, 100 μF
50 V, 47 μF
50 V, 0.1 μF
0.1 μF
10 nF
0.1 μF
0.1 μF
50 V, 0.1 μF
0.047 μF
2200 pF
100 pF
100 pF
10 Ω
100 Ω
Recommended
Sanken Parts
Symbol
Part type
Ratings(1)
EL 1Z
SJPA-D3
SJPA-D3
R3
R4
R5
R6
R7
SKP202
R8
General, chip, 2012
470 Ω
R9
General, chip, 2012
1.5 kΩ
R10
R11
R12
R13
R14
R15
R16
R17
R18
R19
R20
R21
R22
R23
R24
R25
U1
General, chip, 2012
General
General, chip, 2012
General, chip, 2012
General, chip, 2012
General, chip, 2012
General, chip, 2012
General, chip, 2012
General, chip, 2012
General, chip, 2012
General, chip, 2012
General, chip, 2012
General, chip, 2012
General, chip, 2012
General, chip, 2012
General, chip, 2012
IC
10 kΩ
1.35 Ω, 1 W
1.5 kΩ
10 kΩ
12 kΩ
10 kΩ
15 kΩ
10 kΩ
82 kΩ
560 Ω
10 kΩ
10 kΩ
33 kΩ
1 kΩ
Open
22 kΩ
(3)
(2)
(2)
General, chip, 2012
General
General, chip, 2012
General, chip, 2012
General, chip, 2012
10 kΩ
0.22 Ω, 2 W
100 Ω
220 kΩ
11 kΩ
Recommended
Sanken Parts
BL0100A
(1)
Unless otherwise specified, the voltage rating of capacitor is 50V or less, and the power rating of resistor is 1/8W or less.
It is necessary to be adjusted based on actual operation in the application.
(3)
Resistors applied high DC voltage and of high resistance are recommended to select resistors designed against
electromigration or use combinations of resistors in series for that to reduce each applied voltage, according to the
requirement of the application.
(2)
BL0100A-DS Rev.1.2
Apr. 04, 2014
SANKEN ELECTRIC CO.,LTD.
17
BL0100A
OPERATING PRECAUTIONS
In the case that you use Sanken products or design your products by using Sanken products, the reliability largely
depends on the degree of derating to be made to the rated values. Derating may be interpreted as a case that an operation
range is set by derating the load from each rated value or surge voltage or noise is considered for derating in order to
assure or improve the reliability. In general, derating factors include electric stresses such as electric voltage, electric
current, electric power etc., environmental stresses such as ambient temperature, humidity etc. and thermal stress caused
due to self-heating of semiconductor products. For these stresses, instantaneous values, maximum values and minimum
values must be taken into consideration. In addition, it should be noted that since power devices or IC’s including power
devices have large self-heating value, the degree of derating of junction temperature affects the reliability significantly.
Because reliability can be affected adversely by improper storage environments and handling methods, please observe
the following cautions.
Cautions for Storage
 Ensure that storage conditions comply with the standard temperature (5 to 35°C) and the standard relative humidity
(around 40 to 75%); avoid storage locations that experience extreme changes in temperature or humidity.
 Avoid locations where dust or harmful gases are present and avoid direct sunlight.
 Reinspect for rust on leads and solderability of the products that have been stored for a long time.
Cautions for Testing and Handling
When tests are carried out during inspection testing and other standard test periods, protect the products from power
surges from the testing device, shorts between the product pins, and wrong connections. Ensure all test parameters are
within the ratings specified by Sanken for the products.
Soldering
 When soldering the products, please be sure to minimize the working time, within the following limits:
• 260 ± 5 °C
10 ± 1 s (Flow, 2 times)
• 380 ± 10 °C 3.5 ± 0.5 s (Soldering iron, 1 time)
Electrostatic Discharge
 When handling the products, the operator must be grounded. Grounded wrist straps worn should have at least 1MΩ
of resistance from the operator to ground to prevent shock hazard, and it should be placed near the operator.
 Workbenches where the products are handled should be grounded and be provided with conductive table and floor
mats.
 When using measuring equipment such as a curve tracer, the equipment should be grounded.
 When soldering the products, the head of soldering irons or the solder bath must be grounded in order to prevent
leak voltages generated by them from being applied to the products.
 The products should always be stored and transported in Sanken shipping containers or conductive containers, or
be wrapped in aluminum foil.
BL0100A-DS Rev.1.2
Apr. 04, 2014
SANKEN ELECTRIC CO.,LTD.
18
BL0100A
IMPORTANT NOTES
 The contents in this document are subject to changes, for improvement and other purposes, without notice.
Make sure that this is the latest revision of the document before use.
 Application and operation examples described in this document are quoted for the sole purpose of reference
for the use of the products herein and Sanken can assume no responsibility for any infringement of
industrial property rights, intellectual property rights or any other rights of Sanken or any third party which
may result from its use.
 Unless otherwise agreed in writing by Sanken, Sanken makes no warranties of any kind, whether express or
implied, as to the products, including product merchantability, and fitness for a particular purpose and
special environment, and the information, including its accuracy, usefulness, and reliability, included in this
document.
 Although Sanken undertakes to enhance the quality and reliability of its products, the occurrence of failure
and defect of semiconductor products at a certain rate is inevitable. Users of Sanken products are requested
to take, at their own risk, preventative measures including safety design of the equipment or systems
against any possible injury, death, fires or damages to the society due to device failure or malfunction.
 Sanken products listed in this document are designed and intended for the use as components in general
purpose electronic equipment or apparatus (home appliances, office equipment, telecommunication
equipment, measuring equipment, etc.).
When considering the use of Sanken products in the applications where higher reliability is required
(transportation equipment and its control systems, traffic signal control systems or equipment, fire/crime
alarm systems, various safety devices, etc.), and whenever long life expectancy is required even in general
purpose electronic equipment or apparatus, please contact your nearest Sanken sales representative to
discuss, prior to the use of the products herein.
The use of Sanken products without the written consent of Sanken in the applications where extremely high
reliability is required (aerospace equipment, nuclear power control systems, life support systems, etc.) is
strictly prohibited.
 When using the products specified herein by either (i) combining other products or materials therewith or
(ii) physically, chemically or otherwise processing or treating the products, please duly consider all
possible risks that may result from all such uses in advance and proceed therewith at your own
responsibility.
 Anti radioactive ray design is not considered for the products listed herein.
 Sanken assumes no responsibility for any troubles, such as dropping products caused during transportation
out of Sanken’s distribution network.
 The contents in this document must not be transcribed or copied without Sanken’s written consent.
BL0100A-DS Rev.1.2
Apr. 04, 2014
SANKEN ELECTRIC CO.,LTD.
19
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