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http://rohmfs.rohm.com/en/products/databook/datasheet/ic/power/led_driver/bd9483xx-e.pdf
Datasheet
LED Drivers for LCD Backlights
White LED Driver for large LCD
Panels (DCDC Converter type)
BD9483F,FV
●Features
■ 2ch boost DCDC converter with current mode
■ LED protection circuit (Max duty protection, LED
●General Description
BD9483F,FV is a high efficiency driver for white LEDs
and designed for large LCDs. This IC is built-in 2ch
boost DCDC converters that employ an array of LEDs
as the light source. BD9483F,FV has some protect
function against fault conditions, such as the
over-voltage protection (OVP), the over current limit
protection of DCDC (OCP), Max duty protection, LED
OCP protection. Therefore BD9483F,FV is available for
the fail-safe design over a wide range output voltage.
OCP protection)
■ Over-voltage protection (OVP) for the output
voltage Vout
Adjustable soft start
The wide range of analog dimming 0.2V-3.0V
2ch independent PWM dimming input
The UVLO detection for the input voltage of the
power stage
■ FAIL logic output
■
■
■
■
●Key Specification
 Operating power supply voltage range:11.0V to 35.0V
 Oscillator frequency:
150kHz (RT=100kΩ)
 Operating Current:
3mA (typ.)
 Operating temperature range:
-40°C to +85°C
●Package
SOP-24:
Pin Pitch:
●Applications
TV, Computer Display, Notebook, LCD Backlighting
W(Typ.) D(Typ.) H(Max.)
15.00mm x 7.80mm x 2.01mm
1.27mm
●Typical Application Circuit
VOUT2
VOUT1
VCC
VIN
UVLO
VCC
OVP
REG90
VCC
UVLO
VREG
STB
UVLO
TSD
Figure 2-1. SOP-24
OVP
REG90
UVLO
REG90
OSC
+
RT
PWM
COMP
GATE1
CONTROL
LOGIC
CS1
LEB
Current
compensation
Css
SS
SSOP-B24:
Pin Pitch:
PGND1
SS
REG90
DIMOUT1
W(Typ.) D(Typ.) H(Max.)
7.80mm x 7.60mm x 1.35mm
0.65mm
SS-FB
clamper
LEDOCP
CP
Fail
detect
ERROR
amp
FAILB
+
+
-
Ccp
ISENSE1
1.0V
FB1
MAXFB
PWM1
Each channel
PWM2
GATE2
CS2
ADIM
1/3
PGND2
DIMOUT2
ISENSE2
FB2
Figure 2-2. SSOP-B24
Figure 1. Typical Application Circuit
○Product structure:Silicon monolithic integrated circuit
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Datasheet
BD9483F,FV
●Absolute maximum ratings (Ta=25°C)
Parameter
Operating Temperature Range
Storage Temperature Range
Maximum Junction Temperature
Symbol
Ratings
Ta(opr)
-40 to +85
Tstg
-55 to +150
Unit
°C
°C
Tjmax
150
°C
Power Dissipation *1 (SOP24)
Pd1
687
mW
Power Dissipation *2 (SSOP-B24)
Pd2
1024
mW
*1 In the case of mounting 1 layer glass epoxy base-plate of 70mm×70mm×1.6mm, 5.5mW is reduced at 1°C above Ta=25℃.
*2 In the case of mounting 1 layer glass epoxy base-plate of 70mm×70mm×1.6mm, 8.2mW is reduced at 1°C above Ta=25℃
●Operating Ratings (Ta = 25°C)
Parameter
Symbol
Range
Unit
VCC
11.0 to 35.0
V
fsw
50 to 800
kHz
The effective range of ADIM signal
VADIM
0.2 to 3.0
V
PWM input frequency
FPWM
40 to 50k
Hz
Power supply voltage
DC/DC oscillation frequency
The operating conditions written above are constants of the IC unit. Be careful enough when setting the constant in the actual set.
●External Components Recommended Range
Item
REG90 pin connection capacitance
Soft start connection capacitance
RT pin connection resistance
The assumed capacitance of GATE pin
The values described above are constants for a single IC.
Symbol
Setting Range
Unit
CREG90
1.0 to10
μF
CSS
RRT
0.001 to 4.7
15 to 300
μF
kΩ
CGATE
to 1000
pF
Adequate attention must be paid to setting of a constant for an actual set of parts
●Pin Configuration
●Physical Dimension Tape and Marking Diagram
BD9483F
Lot No.
Figure 4-1.
SOP-24
D9483FV
Figure 3.
Lot No.
Figure 4-2.
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BD9483F,FV
●1.1 Electrical Characteristics 1(Unless otherwise specified, Ta=25°C,VCC=24V)
Limit
Parameter
Symbol
Unit
Min.
Typ.
Max.
Condition
【Total current consumption】
Circuit current
Icc
-
3
6
mA
VSTB=3V
Circuit current (stand-by)
Ist
-
25
50
μA
VSTB=0V
Operation voltage(VCC)
VUVLO_VCC
6.0
7.0
8.0
V
VCC=SWEEP UP
Hysteresis Voltage(VCC)
VUHYS_VCC
150
300
600
mV
VCC=SWEEP DOWN
UVLO release voltage
VUVLO
2.91
3.00
3.09
V
VUVLO=SWEEP UP
UVLO hysteresis voltage
VUHYS
150
200
250
mV
VUVLO=SWEEP DOWN
UVLO_LK
-2
0
2
μA
VUVLO=4V
ISENSE threshold voltage 1
VLED1
0.225
0.233
0.242
V
VADIM=0.7V
ISENSE threshold voltage 2
VLED2
0.988
1.000
1.012
V
VADIM=3.0V
ISENSE threshold voltage 3
VLED3
0.989
1.015
1.040
V
VADIM=3.3V
FCT
142.5
150
157. 5
KHz
RT=100kohm
NMAX_DUTY
90
95
99
%
RT=100kohm
RONSO
2.0
4.0
8.0
Ω
ION=-10mA
RONSI
1.2
2.5
5.0
Ω
ION=10mA
SS pin source current
ISSSO
-3.75
-3.0
-2.25
μA
VSS=2V
SS pin ON resistance
RSS_L
-
3.0
5.0
kΩ
VSTB=0V, Ioss=50uA
VSS_END
3.6
4.0
4.4
V
FB source current
IFBSO
-115
-100
-85
μA
FB sink current
IFBSI
85
100
115
μA
SS=SWEEP UP
VISENSE=0.2V, VADIM=3.0V,
VFB=1.0V
VISENSE=2.0V, VADIM=3.0V,
VFB=1.0V
OCP detect voltage
VCS
360
400
440
mV
CS=SWEEP UP
VOVP
2.88
3.00
3.12
V
VOVP_HYS
50
100
150
mV
VOVP SWEEP DOWN
OVP_LK
-2
0
2
μA
VOVP=4V
【UVLO block】
UVLO pin leak current
【DC/DC block】
Oscillation frequency
GATE pin MAX DUTY output
GATE pin ON resistance
(as source)
GATE pin ON resistance
(as sink)
Soft start ended voltage
【DC/DC protection block】
OVP detect voltage
OVP detect hysteresis
OVP pin leak current
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Datasheet
BD9483F,FV
●1.2 Electrical Characteristics 2(Unless otherwise specified, Ta=25°C,VCC=24V)
Limit
Parameter
Symbol
Unit
Min.
Typ.
Max.
Condition
【LED protection block】
LED OCP detect voltage
VLEDOCP
2.88
3.0
3.12
V
VISENSE=SWEEP UP
MAX duty detect voltage
VFBMAX
3.84
4.0
4.16
V
VFB=SWEEP UP
ILADIM
-2
0
2
μA
VADIM=2.0V
IL_ISENSE
-2
0
2
μA
VISENSE=4V
DIMOUT source on-resistance
RONSO
4.0
8.0
16.0
Ω
ION=-10mA
DIMOUT sink on-resistance
RONSI
2.5
5.0
10.0
Ω
ION=10mA
REG90 output voltage
VREG90
8.91
9.00
9.09
V
IO=0mA,VCC>11V
REG90 available current
|IREG90|
15
-
-
mA
REG90_TH
5.4
6.0
6.6
V
REG90_UVLO hysteresis
REG90_HYS
250
500
750
mV
REG90 discharge resistance
REG90_DIS
325
500
675
kΩ
STB pin HIGH voltage
STBH
2.0
-
35
V
VSTB=SWEEP UP
STB pin LOW voltage
STBL
-0.3
-
0.8
V
VSTB=SWEEP DOWN
STB pull down resistor
ISTB
600
1000
1400
kΩ
VSTB=3.0V
PWMx pin HIGH Voltage
PWM_H
2.0
-
5.5
V
VPWMx=SWEEP UP
PWMx pin LOW Voltage
PWM_L
-0.3
-
0.8
V
VPWMx=SWEEP DOWN
PWMx pin Pull Down resistance
RPWM
600
1000
1400
kΩ
VPWMx=3.0V
FAILB pin on-resistance
RFAIL
250
500
1000
Ω
VFAIL=1.0V
FAILB pin leak current
ILFAIL
-2
0
2
μA
VFAIL=15V
CP detect voltage
VCP
2.85
3.0
3.15
V
VCP=SWEEP UP
CP charge current
ICP
2.7
3.0
3.3
μA
【Dimming block】
ADIM pin leak current
ISENSE pin leak current
【REG90 block】
REG90_UVLO detect voltage
REG90=SWEEP DOWN
VSTB=H->L,
REG90=SWEEP UP
VSTB=H->L,
REG90=9.0V
【STB block】
【PWM block】
【FAIL block (OPEN DRAIN)】
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BD9483F,FV
●1.3 Pin Descriptions
In/Out
Rating
[V]
Pin No
Pin Name
Function
1
VCC
-
Power supply pin
-0.3 to 36
2
STB
In
IC ON/OFF pin
-0.3 to 36
3
CS1
In
DC/DC output current detect pin for ch1,OCP input pin for ch1
-0.3 to 7
4
GATE1
Out
DC/DC switching output pin for ch1
-0.3 to 14
5
GND1
-
6
DIMOUT1
Out
7
ISENSE1
In
8
FB1
Out
9
ADIM
10
11
12
Ground for ch1
-
Dimming signal output for NMOS for ch1
-0.3 to 14
Current detection input pin for ch1
-0.3 to 7
Error amplifier output pin for ch1
-0.3 to 7
In
ADIM signal input-output pin
-0.3 to 20
PWM1
In
External PWM dimming signal input pin ch1
-0.3 to 20
PWM2
In
External PWM dimming signal input pin ch2
-0.3 to 20
FAILB
Out
Abnormality detection output pin
13
RT
Out
For DC/DC switching frequency setting pin
-0.3 to 36
-0.3 to 7
14
OVP
In
Over voltage protection detection pin
-0.3 to 20
15
SS
Out
Slow start setting pin
-0.3 to 7
16
CP
Out
Charge timer for abnormal state.
-0.3 to 7
17
UVLO
In
Under voltage lock out detection pin
-0.3 to 20
18
FB2
Out
Error amplifier output pin for ch2
-0.3 to 7
19
ISENSE2
In
Current detection input pin for ch2
-0.3 to 7
20
DIMOUT2
Out
Dimming signal output for NMOS for ch2
-0.3 to 14
21
GND2
-
22
GATE2
Out
23
CS2
In
24
REG90
●1.4.1 Pin ESD Type1
OVP
100k
Out
-
Ground for ch2
DC/DC switching output pin for ch2
-0.3 to 14
DC/DC output current detect pin for ch2,OCP input pin for ch2
-0.3 to 7
9.0V output voltage
-0.3 to 14
UVLO
OVP
50k
5V
SS
UVLO
5V
RT
PWM1 / PWM2
PWMx
100k
5V
ADIM
1M
Figure 5. Pin ESD Type
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BD9483F,FV
●1.4.2 Pin ESD Type2
DIMOUT1 / DIMOUT2 / REG90
GATE1 / GATE2 / REG90 / CS1 / CS2
STB
REG90
REG90
GATEx
DIMOUTx
100k
100k
VCC
VCC
GNDx
GNDx
CSx
ISENSE1 / ISENSE2
FB1 / FB2
CP
ISENSEx
20k
CP
3k
FBx
5V
FAILB
Figure 6. Pin ESD Type
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BD9483F,FV
5
100
4
10
fCT [MHz]
Icc [mA]
●1.5 Typical Performance Curves (Reference data)
3
2
STB=5V
PWM1=PWM2=0V
Ta=25°C
1
14
18
22
26
VCC [V]
30
1
0.1
0.01
0
10
VCC=24V
Ta=25°C
0.001
34
10
100
RT [kohm]
Figure 8. fCT v.s. RT
160
0
140
-20
FB source current [ uA]
FB sink current [uA]
Figure 7. Circuit current
(operating mode)
120
100
80
60
VCC=24V
Ta=25°C
40
20
1000
0
VCC=24V
Ta=25°C
-40
-60
-80
-100
-120
-140
-160
0.5
1.5
2.5
FB [V]
3.5
0.5
Figure 9. FB sink current v.s. FB voltage
1.5
2.5
FB [V]
3.5
Figure 10. FB source current v.s. FB voltage
1.4
1.2
ISE NSE [V]
1.0
0.8
0.6
0.4
VCC=24V
Ta=25°C
0.2
0.0
0
1
2
ADIM [V]
3
Figure 11. ISENSE feedback voltage v.s. ADIM
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BD9483F,FV
●2 Block Diagram
VOUT2
VOUT1
VCC
VIN
UVLO
VCC
OVP
REG90
VCC
UVLO
VREG
STB
UVLO
OVP
TSD
REG90
UVLO
REG90
OSC
+
RT
PWM
COMP
GATE1
CONTROL
LOGIC
CS1
LEB
Current
compensation
Css
SS
PGND1
SS
REG90
DIMOUT1
SS-FB
clamper
LEDOCP
CP
Fail
detect
ERROR
amp
FAILB
+
+
-
Ccp
ISENSE1
1.0V
FB1
MAXFB
PWM1
Each channel
PWM2
GATE2
CS2
ADIM
PGND2
1/3
DIMOUT2
ISENSE2
FB2
Figure 12. Block Diagram
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BD9483F,FV
●3.1 Pin Function
VCC (1 PIN)
Power supply pin of IC. Input range is from 11V to 35.0V.
The operation starts more than 7.0V(typ.) and shuts down less than 6.7V(typ.) by VCCUVLO.
In the lower VCC than 7.6V(typ.), IC stops switching by REG90UVLO, which detect the lower voltage of VCC earlier than
VCCUVLO.
STB (2 PIN)
STB can be used to perform the reset of latch off or soft start. The power control of REG90 is depend on STB pin and the
VCCUVLO.
Regarding of the sequence of turning on, after the positive edge of PWM is input, BD9483F,FV starts the boost operation
and the soft start.
The input voltage of STB pin toggles the IC state(IC ON/OFF). Please avoid the use of the intermediate level (from 0.8V
to 2.0V).
CS1 (3 PIN), CS2 (23 PIN)
The CS pin has two functions.
1. DC / DC current mode Feedback terminal
The inductor current is converted to the CS pin voltage by the sense resistor RCS
and this CS pin voltage controls the gate duty.
VIN
2. Inductor current limit (OCP) terminal
The CS terminal also has an over current protection (OCP), if it voltage is more
than 0.4V, the switching operation will be stopped compulsorily. And the next
GATE
boost pulse will be restart in normal frequency.
If the capacitance Cs in the right Figure is increased to a micro orders, please be
CS
careful that the limited value of NMOS drain current Id is much than the simple
Cs
Rcs
calculation. Because the current Id flow not only Rcs but also Cs, as the CS pin
Figure 13.
voltage move according to Id.
GND
Both of above functions are enable after 300ns (typ.) when GATE pin asserts
high, because the leading Edge Blanking function is included into this IC to prevent the noise affection. Please refer to
the section “●3.5.1 how to set OCP / the calculation method for the current rating of DCDC parts”, for detail explanation.
GATE1 (4 PIN), GATE2 (22 PIN)
This is the output terminal for driving the gate of the boost MOSFET. The high level is REG90 of IC. Frequency can be
set by the resistor connected to RT. Please refer to the <RT> pin description for the frequency setting.
In the condition of approximately VCC<9.8V, the high level of the GATE pin is about VCC-0.8V, which lower than 9.0V.
The phase lag of GATE1 and GATE2 is shown in Figure below. This Figure illustrates the waveform as both GATE pin
output the maximum duty. The inrush current of the VIN terminal can be suppressed because each channel turns on
alternately.
Figure 14.
GND1 (5 PIN), GND2 (21 PIN)
GND pin of IC. GND1 is the ground pin of channel 1.
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BD9483F,FV
DIMOUT1 (6 PIN), DIMOUT2 (20 PIN)
This is the output pin for external NMOS of dimming. The below table shows the rough
output logic of each operation state, and the output H level is REG90. DIMOUT1 and
DIMOUT2 are the output corresponding to PWM1 and PWM2. Please refer to the time
chart in the section 3.7 for detail explanations, because The DIMOUT logic has the
exceptional behavior. Please insert the resistance between the dimming MOS gate to
improve the over shoot of LED current, as PWM turns from low to high.
Status
DIMOUT1 output
DIMOUT2 output
Normal
PWM1
PWM2
Abnormal
Low Level
Low Level
Vout
REG90
DIMOUT
RDIM
ISENSE
BD9483
Figure 15.
FB1 (8 PIN), FB2 (18 PIN)
This is the output terminal of error amplifier. The input pin of error amplifier is ISENSE
and ADIM.
After the completion of the soft start, this pin outputs high impedance as the
corresponding PWM pin asserts low. FB voltage is hold to the external capacitance.
○FBMAX Protection Function
More than FB = 4.0V (typ.), the error state for the GATE pin duty will be detected,
and the CP charge is started. If the CP charge continues to 3.0V, IC will be latched off.
Please refer to the time chart 3.7.5
(The loop compensation setting is described in the section " ●3.6 loop compensation".)
Vout
DIMOUT
Error AMP
+
+
-
ISENSE1 (7 PIN), ISENSE2 (19 PIN)
This is the input terminal for the current detection. The error amplifier compares the
ISENSE and the 1/3 of ADIM pin voltage. And the clamped level of ISENSE feedback
is 1.0V.
○LED OCP Protection Function
More than ISENSE = 3.0V (typ.), the over current of LED (LEDOCP) will be detected.
The GATE pulse will be stopped, the DIMOUT is forced to output high level to monitor
the error state. If the detection continues to 4 count of GATE frequency, IC will be
latched off. (Please refer to the time chart 3.7.6)
ISENSE
1.00V
FB
Figure 16.
ADIM (9 PIN)
The input pin for analog dimming signal. The ISENSE feedback point is set as 1/3 of this pin bias. If more than 3.0V is
input, ISENSE threshold is clamped as the below diagram.
Figure 17.
PWM1 (10 PIN), PWM2 (11 PIN)
The ON / OFF input of the LED light. PWM1 and PWM2 controls each LED strings individually. The Duty signal of this pin
can control the PWM dimming.
The high / low level of PWM pins are following.
State
PWM input voltage
PWMx=H
PWMx=2.0V to 5.5V
PWMx=L
PWMx=-0.3V to 0.8V
FAILB (12 PIN)
FAIL signal output pin (open drain). As abnormal, the internal NMOS turn on.
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BD9483F,FV
Status
FAILB output
Normal
OPEN
Abnormal
GND Level
RT (13 PIN)
DC/DC switching frequency setting pin. RT set the oscillation frequency inside IC.
○The relationship between the frequency and RT resistance value (ideal)
R RT 
15000
f SW [kHz]
[kΩ ]
The oscillation setting range from 50kHz to 800kHz.
The setting examples is separately described in the section ” ●3.4.4 how to set DCDC oscillation frequency”
OVP (14 PIN)
The OVP terminal is the input for over-voltage protection. As OVP is more than 3.0V, the over-voltage protection (OVP)
will work. At the moment of these detections, the BD9483F,FV stops the switching of the output GATE and starts to count
up the abnormal interval, but IC doesn't reach latch off state instantaneously until the detection continues up to 4 counts
of GATE terminals. (Please refer to the time chart 3.7.4)
As the latch off by OVP, both channels stop. (GATE1=GATE2=L, DIMOUT1=DIMOUT2=L)
The OVP pin is high impedance, because the internal resistance to a certain bias is not connected.
So, the bias by the external components is required, even if OVP function is not used, because the open connection of
this pin is not fixed the potential.
The setting examples is separately described in the section ”●3.4.6 how to set OVP”
SS (15 PIN)
The pin which sets soft start interval of DC/DC converter. It performs the constant current charge of 3.0 μA to external
capacitance Css(0.001μF to 4.7μF). The switching duty of GATE output will be limited during 0V to 4.0V of the SS
voltage.
So the equality of the soft start interval can be expressed as following
6
Tss = 1.33*10 *Css
Css: the external capacitance of the SS pin.
Regarding of the logic of SS=L
(SS=L) = (PWM1orPWM2 have not asserted H since ResetB=L->H) or (latch off state)
where ResetB = (STB=H) and (VCCUVLO=H) and (REG90UVLO=H)
Please refer to the time chart 3.7.3 on soft start behavior
CP (16 PIN)
Timer pin for counting the abnormal state of the FBMAX protection. If the abnormal state is detected, The CP pin start
charging by 3μA to the external capacitance. As the CP voltage reaches to 3.0V, IC will be latched off. In latch off both
channels will be stopped (GATE1=GATE2=L, DIMOUT1=DIMOUT2=L).
Please refer to the section “●3.4.7 how to set the interval until latch off (CP pin)” for more detail.
UVLO (17 PIN)
Under voltage lock out pin for the input voltage of the power stage. More than 3.0V(typ.), IC starts the boost operation
and stops lower than 2.8V(typ.).
The UVLO pin is high impedance, because the internal resistance to a certain bias is not connected.
So, the bias by the external components is required, even if UVLO function is not used, because the open connection of
this pin is not fixed the potential.
As the latch off by UVLO, both channels stop. (GATE1=GATE2=L, DIMOUT1=DIMOUT2=L)
The setting examples is separately described in the section ”●3.4.5 how to set UVLO”
REG90 (24 PIN)
This is the 9.0V (typ.) output pin that is used for the power supply of DIMOUT, GATE. Available current is 15mA (min.).
When VCC<11V , REG90 output voltage decreases because of the saturation.
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●3.2 The detection condition list of the protection (TYP. Condition)
Detect condition
Detection
pin
pin condition
Release
condition
Timer
operation
Protection type
PWM
SS
FBMAX
FB
FB > 4.0V
H(8clk)
SS>4.0V
FB < 4.0V
CP charge
Latch off
LED OCP
ISENSE
ISENSE > 3.0V
-
-
ISENSE < 3.0V
4clk
Latch off
UVLO
UVLO
UVLO<2.8V
-
-
UVLO>3.0V
NO
Auto recovery
REG90UVLO
REG90
REG90<6.0V
-
-
REG90>6.5V
NO
Auto recovery
VCC UVLO
VCC
VCC<6.7V
-
-
VCC>7.0V
NO
Auto recovery
OVP
OVP
OVP>3.0V
-
-
OVP<2.9V
4clk
Latch off
OCP
CS
CS>0.4V
-
-
-
NO
Pulse by Pulse
Protection
To reset the latch type protection, please input of STB logic to ‘L’ once. Otherwise the detection of VCCUVLO, REG90UVLO is
required.
In the latch off mode, both channels will be stopped. (GATE1=GATE2=L, DIMOUT1=DIMOUT2=L)
The clock number of timer operation is the correspond to the boost pulse clock.
●3.3 The behavior list of the protection
The operation of the protection
Protect Function
DC/DC Gate
output
Dimming transistor
(DIMOUT) logic
SS pin
FAILB pin
(NORMAL=open)
FBMAX
Stops after latch
L after latch
discharge after latch
L after latch
LED OCP
Stops immediately
H immediately, L after latch
discharge after latch
L after latch
STB
Stops immediately
L after REG90UVLO detects
discharge immediately
OPEN
UVLO
Stops immediately
immediately L
discharge immediately
Low
REG90UVLO
Stops immediately
immediately L
discharge immediately
OPEN
VCC UVLO
Stops immediately
immediately L
discharge immediately
Low
OVP
Stops immediately
immediately L
discharge after latch
L after latch
OCP
Stops immediately
Normal operation
Not discharge
OPEN
Please refer to the timing chart for the detail.
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●3.4 External components selection
●3.4.1 The start up operation and the setting of Soft Start external capacitance
The below explanations are the start up sequency of BD9483F,FV.
①
OSC
SS
SLOPE
SS
N
DRIVER
SS-FB
Circuit
PWM
GATE ②
OSC
0.7V
DIMOUT
LED_OK
VOUT
LED_OK
COMP
Css
SS=0.4V
FB
③
PWM=L:STOP
ILED
VOUT
5V
ILED
SS
FB
3uA
STB
④
ISENSE
PWM
⑤
⑥
Figure 19.
○The explanation of start up sequency
①The internal bias voltage of REG90 turns on by VCCUVLO. And as STB is H, the reset signal is released.
②With the first PWM=H, BD9483F,FV enables to output the boost pulse, and the SS start to charge to the external
capacitance. At this moment, the voltage of FB will be clamped to SS+0.7V voltage regardless of the PWM logic.
③The boost of VOUT (GATE pulse) is started as SS=0.4V(typ), because the internal ramp reaches the bottom voltage of
saw-toothed wave and the DC/DC start to output the pulse signal.
④VOUT is boosted to a certain level, and the LED current is rising.
⑤When the LED current reached to a certain level, FB is removed from SS+0.7V internally. And the start up operation
completed. By this SS-FB clamped circuit, turning on can be completed quickly in spite of small PWM duty.
⑥IC start the normal operation by sensing the voltage of ISENSE pin. FBMAX detection starts monitoring.
○The setting method of SS external capacitance
As above described, SS continues to be charged in spite of PWM logic or VOUT level, and FB level is clamped by
SS+0.7V.
TFB is defined as the time for the SS voltage to reach to the FB feedback voltage.
When the FB voltage during LED turns on is expressed VFB, the equality on TFB is the following.
TFB 
Css [F] VFB[V]
[Sec]
3[A]
●3.4.2 Shutdown method and the setting of REG90 capacitance
When this IC shuts down, VOUT discharge function works. Indicate the sequence.
Figure 21.
Figure 20.
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○Sequence explanation of shut down
1. When ENA=L, DCDC and REG90 is stopped.
2. While ENA=L and REG90UVLO=H, DIMOUT asserts the same logic of PWM. And VOUT is discharged until
REG90=9.0V is reached to 6.0V by 500kΩ.
3. VOUT is enough discharged by ILED, ILED don’t get to flow.
4. REG90 voltage is reached under 6.0V(typ.), whole system is shutdown.
○Setting method of REG90 capacitance
Shutdown time TOFF is decided by the following equation.
TOFF [sec]  C REG [F]  R REG []  In
REG90 t 0 [V]
9.0[V]
 C REG [F]  500[k]  in
 20.2  10 5  C REG [sec]
REG90 UVLO [V]
6.0[ V ]
When discharge function is used, PWM signal must be continued to input after ENA=L.
VOUT discharge time is longest when PWM is set on mininum DUTY.
Please set CREG capacitance value with margin so that the system is shutdown after VOUT is enough
discharged.
●3.4.3 The LED current setting
LED current can be adjusted by setting the resistance RISENSE which connects to ISENSE
pin.
○the relationship between RISENSE and ILED current
R ISENSE 
Without DC dimming (ADIM>3.0V)
R ISENSE
ADIM[V]/3
[ ]
I LED [A]
DIMOUT
1.0[V]

[ ]
I LED [A]
Error AMP
+
+
-
With DC dimming (ADIM<3.0V)
Vout
[setting example]
If ILED current is 400mA as ADIM is 3.0V, we can calculate RISENSE as below.
R ISENSE 
1.0V
RISENSE
FB
ISENSE[V] ADIM / 3[V] 3.0 / 3[V]


 2.5[ ] I LED [A]
I LED [A]
0.4[A]
●3.4.4 how to set DCDC oscillation frequency
RRT which connects to RT pin set the oscillation frequency of DCDC.
ISENSE
Figure 22.
○ the relationship between OSC and RRT (ideal)
R RT 
15000
f SW [kHz]
[k  ]
where fsw is the oscillation frequency of DCDC [kHz]
Frequency (fsw)
Ideal
GATE
CS
RT
Rcs
RRT
GND
Figure 23.
Figure 24.
This equation is an ideal equation in which correction factors are not applied.
The adequate verification with an actual set needs to be performed to set frequency precisely.
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[setting example]
If DCDC oscillation frequency is 200kHz, we can calculate the RRT as below.
R RT 
15000
15000

 75 [k]
f sw [kHz] 200[kHz]
●3.4.5 how to set UVLO
Under voltage lock out pin for the input voltage of the power stage. More than 3.0V(typ.), IC starts boost operation and
stops lower than 2.8V(typ.).
The UVLO pin is high impedance, because the internal resistance to a certain bias is not connected.
So, the bias by the external components is required, even if UVLO function is not used, because the open connection of
this pin is not fixed the potential.
The resistor value can be calculated by the below formula.
○UVLO detection equality
As VIN is decreases, R1, R2 value is expressed the following formula by
the VINdet, the detect voltage of UVLO.
R1  R2[k] 
VIN
(VINDET [V]  2.8[V])
[k]
2.8[V]
○UVLO release equality
By using the R1, R2 in the above equality, the release voltage of UVLO can
be expressed as following.
VINCAN  3.0V 
(R1[k]  R2[k])
R2[k]
ON/ OFF
UVLO
+
-
2.8V/3.0V
R1
R2
CUVLO
[V]
Figure 25.
[setting example]
If the normal input voltage, VIN is 24V, the detect voltage of UVLO is 18V, R2 is 30k ohm, R1 is calculated as following.
R1  R2[k]
(VINDET[V]  2.8[V])
(18[V]  2.8[V])
 30[k] 
 162.9[k]
2.8[V]
2.8[V]
By using these R1, R2, the release voltage of UVLO, VINcan can be calculated too as following.
VINCAN  3.0[V]
R1[k]  R2[k]
162.9[k]  30[k]
 3.0[V]
[V]  19.29[V]
R2[k]
30[k]
●3.4.6 how to set OVP
The OVP terminal is the input for over-voltage protection of output voltage.
The OVP pin is high impedance, because the internal resistance to
a certain bias is not connected.
So, the bias by the external components is required, even if OVP
function is not used, because the open connection of this pin is not
fixed the potential.
The resistor value can be calculated by the below formula.
VOUT
OVP
R1
-
○OVP detection equality
If the VOUT is boosted abnormally, VOVPdet is the detect voltage of
OVP, R1, R2 can be expressed by the following formula.
R1  R2[k] 
(VOVPDET [V]  3.0[V])
[k]
3.0[V]
OVP
+
2.9V/3.0V
R2
COVP
Figure 26.
○OVP release equality
By using the R1, R2 in the above equality, the release voltage of OVP, VOVPcan can be expressed as following.
VOVPCAN  2.9V 
(R1[k]  R2[k])
R2[k]
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[setting example]
If the normal output voltage, VOUT is 40V, the detect voltage of OVP is 48V, R2 is 10k ohm, R1 is calculated as
following.
R1  R2[k] 
(VOVPDET [V]  3.0[V])
(48[V] 3[V])
 10[k] 
 150 [k]
3.0[V]
3[V]
By using these R1, R2, the release voltage of OVP, VOVPcan can be calculated as following.
VOVPCAN  2.9[V]
(R1[k]  R2[k])
10[k]  150[k]
 2.9[V]
[V]  46.4 [V]
R2[k]
10[k]
●3.4.7 how to set the interval until latch off (CP pin)
BD9483F,FV starts the counting up (charging CP pin) by the detection of FBMAX abnormal state, and BD9483F,FV falls
to the latch off state when the following interval has passed.
Only PWM=L input does not reset the timer counter, as the abnormal state continues.
LATCHTIME = 1.0 * 106 * Ccp [sec]
Where LATCHTIME is the interval until latch off state
CCP is the external capacitor of CP pin.
[setting example]
If the capacitor of CP pin is 0.47uF, the timer latch interval is as following.
LATCHTIME = 1.0 * 106 * Ccp [sec] = 1.0 * 106 * 0.47 * 10-6 [sec] = 470 [msec]
(the calculation method of the coil peak current, Ipeak)
At first, since the ripple voltage at CS pin depend on the application condition of
DCDC, those put onto the equality to calculate as following.
The output voltage = VOUT [V]
LED total current = IOUT [A]
The DCDC input voltage of the power stage = VIN [V]
The efficiency of DCDC =η[%]
And then, the averaged input current IIN is calculated by the following
equality
VOUT [V]  I OUT [A]
[A]
VIN [V]  η[%]
And the ripple current of the inductor L (ΔIL[A]) can be calculated by using
DCDC the switching frequency, fsw, as following.
ΔIL 
(VOUT [V]  VIN [V])  VIN [V]
L[H]  VOUT [V]  f SW [Hz]
IL
fsw
GATE
CS
Rcs
GND
Figure 27.
(V)
(A)
(t)
[A ]
Ipeak
ΔIL
IIN
ΔIL[A]
2
[A]
… (1)
(t)
(V)
0.4V
VCS[V]
Therefore, the bottom of the ripple current Imin is
Imin  I IN [A] 
Imin
IL[A]
On the other hand, the peak current of the inductor Ipeak can be expressed
as the following equality.
Ipeak  I IN [A] 
ΔIL[A]
or 0
2
VCSpeak
As Imin>0, that operation mode is CCM (Continuous Current Mode),
otherwise another mode is DCM (Discontinuous Current Mode).
Figure 28.
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VOUT
N[V]
I IN 
L
IOUT
●3.5 DCDC parts selection
●3.5.1 how to set OCP / the calculation method for the current rating of DCDC parts
BD9483F,FV stops the switching by the OCP detect, when the CS pin voltage is
more than 0.4V. The resistor value of CS pin, RCS need to be considered by the
coil L current. And the current rating of DCDC external parts is required more
VIN
than the peak current of the coil.
It is shown below that the calculation method of the coil peak current, the
selection method of Rcs (the resistor value of CS pin) and the current rating of
the external DCDC parts.
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(the selection method of Rcs)
Ipeak flows into Rcs and that cause the voltage signal to CS pin. (Please refer the right timing chart)
That peak voltage VCSpeak is as following.
VCS peak  Rcs  Ipeak
[V]
As this VCSpeak reaches to 0.4V, the DCDC output stops the switching.
Therefore, Rcs value is necessary to meet the under condition.
Rcs  Ipeak[V]  0.4[V]
(the current rating of the external DCDC parts)
The peak current as the CS voltage reaches to OCP level (0.4V) is defined as Ipeak_det.
I peak_det 
0.4[V]
Rcs[  ]
[A]
… (2)
The relation among Ipeak (equality (1)), Ipeak_det (equality (2)) and the current rating of parts is required to meet the
following
I peak  I peak _ det 
The current rating of parts
Please make the selection of the external parts to meet the above condition such as FET, Inductor, diode.
[setting example]
The output voltage = VOUT [V] = 40V
LED total current = IOUT [A] = 0.48V
The DCDC input voltage of the power stage = VIN [V] = 24V
The efficiency of DCDC =η[%] = 90%
The averaged input current IIN is calculated as the following.
I IN [A] 
VOUT [V] I OUT [A] 40[V] 0.48[A]

 0.89 [A]
VIN [V] η[%]
24[V] 90[%]
And the ripple current of the inductor L (ΔIL[A]) can be calculated if the switching frequency, fsw = 200kHz, the inductor,
L=100μH.
ΔIL 
(VOUT [V]  VIN [V])  VIN [V]
(40[V]  24[V])  24[V]

 0.48
L[H]  VOUT [V]  f SW [Hz]
100  10  6 [H]  40[V]  200  10 3 [Hz]
[A]
Therefore the inductor peak current, Ipeak is
Ipeak  I IN [A] 
ΔIL[A]
0.48[A]
 0.89[A] 
 1.13[A]
2
2
…The calculation result of the peak current
If Rcs is assume to be 0.3 ohm
VCS peak  Rcs  Ipeak  0.3[  ]  1.13[A]  0.339[V]  0.4V
…The Rcs value confirmation
The above condition is met.
And Ipeak_det, the current OCP works is
I peak_det 
0.4[V]
 1.33[A]
0.3[  ]
If the current rating of the used parts is 2A,
I peak  I peak _ det 
The current rating
 1.13[ A]  1.33[ A]  2.0[ A]
…
The current rating confirmation of DCDC parts
This inequality meets the above relationship. The parts selection is proper.
And Imin, the bottom of the IL ripple current can be calculated as following.
I MIN  I IN [A] 
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This inequality implies the operation is the continuous current mode.
●3.5.2 Inductor selection
The inductor value affects the input ripple current.
ΔIL 
ΔIL
I IN 
VIN
(VOUT [V]  VIN [V])  VIN [V]
L[H]  VOUT [V]  f SW [Hz]
VOUT [V]  I OUT [A]
[A]
VIN [V]  η[%]
Ipeak  I IN [A] 
IL
L
VOUT
RCS
[A]
ΔIL[A]
2
[A]
Where
L: the coil inductance [H]
Vout: the DCDC output voltage [V]
Vin: the input voltage [V]
Iout: the output load current (the summation of LED current) [A]
Iin: the input current [A]
Fsw: the oscillation frequency [Hz]
COUT
Figure 29.
* The current exceeding the rated current value of inductor flown through the coil causes magnetic saturation, results
in decreasing in efficiency. Inductor needs to be selected to have such adequate margin that peak current does not
exceed the rated current value of the inductor.
* To reduce inductor loss and improve efficiency, inductor with low resistance components (DCR, ACR) needs to be
selected
●3.5.3 Output capacitance Cout selection
Output capacitor needs to be selected in consideration of equivalent series
VIN
resistance required to even the stable area of output voltage or ripple voltage.
Be aware that set LED current may not be flown due to decrease in LED
IL
terminal voltage if output ripple component is high.
Output ripple voltage VOUT is determined by Equation (4):
L
VOUT
RESR
RCS
ΔVOUT  ILMAX  R ESR 
1
C OUT

I OUT
1

[V] ・・・・・
η
f SW
(4)
where, RESR is the equivalent series resistance of Cout.
COUT
Figure 30.
* Rating of capacitor needs to be selected to have adequate margin against output voltage.
* To use an electrolytic capacitor, adequate margin against allowable current is also necessary. Be aware that the
LED current is larger than the set value transitionally in case that LED is provided with PWM dimming especially.
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●3.5.4 MOSFET selection
Though there is no problem if the absolute maximum rating is larger than the rated current of the inductor L, or is
larger than the sum of the tolerance voltage of COUT and the rectifying diode VF. The product with small gate
capacitance (injected charge) needs to be selected to achieve high-speed switching.
* One with over current protection setting or higher is recommended.
* The selection of one with small on resistance results in high efficiency.
●3.5.5 Rectifying diode selection
A schottky barrier diode which has current ability higher than the rated current of L, the reverse voltage larger than the
tolerance voltage of COUT, and the low forward voltage VF especially needs to be selected.
●3.6
Loop compensation
A current mode DCDC converter has each one pole (phase lag) fp due to CR filter composed of the output capacitor
and the output resistance (= LED current) and zero (phase lead) fZ by the output capacitor and the ESR of the
capacitor.
Moreover, a step-up DCDC converter has RHP zero (right-half plane zero point) fZRHP which is unique with the boost
converter. This zero may cause the unstable feedback. To avoid this by RHP zero, the loop compensation that the
cross-over frequency fc set as following, is suggested.
fc = fZRHP /5 (fZRHP: RHP zero frequency)
Considering the response speed, the below calculated constant is not always optimized completely. It needs to be
adequately verified with an actual device.
VIN
VOUT
ILED
L
VOUT
-
FB
gm
RESR
RCS
+
Figure 32.
The output voltage block
The error amp block
Calculate the pole frequency fp and the RHP zero frequency fZRHP of DC/DC converter
fp 
I LED
[Hz] 2π  VOUT  COUT
Calculate the phase compensation of the error amp output (fc = fZRHP/5)
R FB1 
Where
iii.
VOUT  (1  D) 2
[Hz] 2π  L  I LED
 VIN
V
(Continuous Current Mode)
D  OUT
VOUT
f ZRHP 
Where ILED = the summation of LED current,
ii.
CFB2
CFB1
Figure 31.
i.
RFB1
COUT
f RHZP  R CS  I LED
[Ω] 5  f p  gm  VOUT  (1  D)
C FB1 
1
[F] 2π  R FB1  f p
gm  4.0  10 4 [ S ]
Calculate zero to compensate ESR (RESR) of COUT (electrolytic capacitor)
C FB2 
R ESR  C OUT
[F] R FB1
*When a ceramic capacitor (with RESR of the order of milliohm) is used to COUT, the operation is stabilized by
insertion of CFB2.
To improve the transient response, RFB1 need to be increase, CFB1 need to be decrease. It needs to be adequately verified
with an actual device in consideration of vary from parts to parts since phase margin is decreased.
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●3.7 Timing chart
●3.7.1 starting up 1 (STB inputs and PWM signal succeeds)
Figure 33.
(*1)…REG90 starts up when VCC is more than 7.0V and STB=H.
(*2)…When REG90 is more than 6.5V, the reset signal is released. The pin SS is not charged in the state that the PWM signal is
not input, the boost is not started.
(*3)…The charge of the pin SS starts by the positive edge of PWM1orPWM2=L to H, and the soft start starts. The GATEx pulse
outputs only during the corresponding PWMx=H. And as the SS is less than 0.4V(typ), the pulse does not output. The pin
SS continues charging in spite of the assertion of PWM or OVP level.
Please refer to the section “●3.1 Pin Function/SS”.
(*4)…The soft start interval will end if the voltage of the pin SS, Vss reaches to 4.0V. By this time, BD9483F,FV boost Vout to the
voltage where the set LED current flows. It is started to monitor the abnormal detection of FBMAX.
(*5)…As STB=L, instantaneously the boost operation is stopped. (GATEx=L, SS=L)
(*6)…As STB=H again, the boost operation restarts by the next PWM=H. It is the same operation as the timing of (*2).
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●3.7.2 starting up 2 (PWM signal inputs and STB succeeds)
7.0V
VCC
STB
PWM1
orPWM2
6.5V
REG90
4.0V
0.4V
SS
0.4V
GATEx
FAILB
H
OFF
SS
(*1) (*2)
NORMAL
(*3)
STANDBY
(*4)
SS
(*5)
Figure 34.
(*1)…REG90 starts up when STB=H.
(*2)…When REG90 is more than 6.5V, the reset signal is released. In the first PWM=H the soft-start begins the changing
immediately. The GATEx pulse outputs only during the corresponding PWMx=H. And as the SS is less than 0.4V(typ), the
pulse does not output. The pin SS continues charging in spite of the assertion of PWM or OVP level.
(*3)…The soft start interval will end if the voltage of the pin SS, Vss reaches to 4.0V. By this time, BD9483F,FV boost Vout to the
point where the set LED current flows. It is started to monitor the abnormal detection of FBMAX.
(*4)…As STB=L, instantaneously the boost operation is stopped. (GATE=L, SS=L)
(*5)…As STB=H again, it is the same operation as the timing of (*1).
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●3.7.3 the soft start function
Figure 35.
(*1)…The SS pin charge does not start by just STB=H. “PWM1=H or PWM2=H” is required to start the soft start. In the low SS
voltage, the GATE pin duty is depend on the SS voltage. And as the SS is less than 0.1V, the pulse does not output.
(*2)…By the low STB=L, the SS pin is discharged immediately.
(*3)…As the STB recovered to STB=H, The SS charge starts immediately by the logic “PWM1 or PWM2=H” in this chart.
(*4)…The SS pin is discharged immediately by the UVLO=L and FAILB is changed OPEN to Low.
(*5)…The SS pin is discharged immediately by the VCCUVLO=L and FAILB is changed OPEN to Low.
(*6)…The SS pin is discharged immediately by the REG90UVLO=L and FAILB keeps OPEN.
(*7)…The SS pin is not discharged by the abnormal detection of the latch off type such as OVP until the latch off.
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RESET
START
END
START
RESET
START
●3.7.4 the OVP detection
Figure 36.
(*1)…As OVP is detected, the output GATE=L, DIMOUT=L, and the abnormal counter starts
(*2)…If OVP is released within 4 clock of abnormal counter of the GATE pin frequency, the boost operation restarts.
(*3)…As the OVP is detected again, the boost operation is stopped.
(*4)…As the OVP detection continues up to 4 count by the abnormal counter, IC will be latched off. Both channels will be
stopped. (GATE1=GATE2=L, DIMOUT1=DIMOUT2=L)
(*5)…As the latched off, the boost operation doesn't restart even if OVP is released.
(*6)…The STB=L input can make IC reset.
(*7)…It normally starts as STB turns L to H.
(*8)…The operation of the OVP detection is not related to the logic of PWM.
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●3.7.5 FBMAX detection
Figure 37.
(*2)…During the soft start, it is not judged to the abnormal state even if the FB=H(FB>4.0V).
(*3)…When the PWM=H and FB=H, the abnormal counter doesn’t start immediately.
(*4)…The CP charge will start if the PWM=H and the FB=H detection continues 8 clock of the GATE frequency. Once the count
starts, only FB level is monitored.
(*5)…When the FBMAX detection continues till the CP charge reaches to 3.0V, IC will be latched off. The latch off interval can
be calculated by the external capacitance of CP pin. (Please refer the section 3.4.7.) In latch off mode, both CH1 and CH2
will be stopped.
(*6)…The latch off state can be reset by the STB=L.
(*7)…It is normally started by PWM=L to H, in this Figure.
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●3.7.6 LED OCP detection
STB
PWM1or
PWM2
3.0V
INSENSE
Abnormal
COUNTOR
3.0V
3.0V
3.0V
3.0V
4count
4count
Smaller than
4count
3.0V
SS
0.4V
GATE
DIMOUT
FAILB
STATE
NORMAL LEDOCP
NORMAL
abnormal
(*1)
(*2)
abnormal
(*3)
Reset
Latch off
LEDOCP
(*4) (*5)
(OFF)
(*6)
(*7)
LEDOCP
NORMAL
Latch off
abnormal
(*8)
Figure 38.
(*1)…If ISENSE>3.0V, LEDOCP is detected, it becomes GATE=L. To detect LEDOCP continuously, The DIMOUT is
compulsorily high, regardless of the PWM dimming signal.
(*2)…When the LEDOCP releases within 4 counts of the GATE frequency, the boost operation restarts.
(*3) …As the LEDOCP is detected again, the boost operation is stopped, too.
(*4)…If the LEDOCP detection continues up to 4 counts of GATE frequency. IC will be latched off.
(*5)…Once IC is latched off, the boost operation doesn't restart even if the LEDOCP releases. And both CH1 and CH2 will be
stopped.
(*6)…The latch off state can be reset by the STB=L.
(*7)…It normally starts by STB=L to H.
(*8)…The operation of the LEDOCP detection is not related to the logic of the PWM.
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●3.7.7 the spontaneous detection OVP and FBMAX.
STB
3.0V
OVP
FB
3.0V
2.9V
4.0V
4.0V
4.0V
2.9V
4.0V
SS
4count
END
4count
START
Abnormal
COUNTOR
END
START
CP
0.4V
GATE
DIMOUT
FAILB
STATE
NORMAL
(*1)
COUNTOR
(*2)
Latch off
(*3)
Reset
NORMAL COUNTOR
(*4)
(*5)
Latch off
(*6)
Figure 39.
(*1)…As the FBMAX is detected, the CP charge is started.
(*2)…As the OVP is detected, the abnormal counter is started, the CP charge is not reset.
(*3)…IC is latched off by OVP.
(*4)…The latch mode is reset by STB=L
(*5)…If the FBMAX is detected during OVP, the CP charge is started.
(*6)…The OVP counties to 4clk, IC is latched off. And the CP charge is reset.
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●Operational Notes
1.) This product is produced with strict quality control, but might be destroyed if used beyond its absolute maximum ratings including
the range of applied voltage or operation temperature. Failure status such as short-circuit mode or open mode can not be
estimated. If a special mode beyond the absolute maximum ratings is estimated, physical safety countermeasures like fuse
needs to be provided.
2.) Connecting the power line to IC in reverse polarity (from that recommended) may cause damage to IC. For protection against
damage caused by connection in reverse polarity, countermeasures, installation of a diode between external power source and IC
power terminal, for example, needs to be taken.
3.) When this product is installed on a printed circuit board, attention needs to be paid to the orientation and position of IC. Wrong
installation may cause damage to IC. Short circuit caused by problems like foreign particles entering between outputs or
between an output and power GND also may cause damage.
4.) Since the back electromotive force of external coil causes regenerated current to return, countermeasures like installation of a
capacitor between power source and GND as the path for regenerated current needs to be taken. The capacitance value must
be determined after it is adequately verified that there is no problem in properties such that the capacity of electrolytic capacitor
goes down at low temperatures. Thermal design needs to allow adequate margin in consideration of allowable loss (Pd) in
actual operation state.
5.) The GND pin needs to be at the lowest potential in any operation state.
6.) Thermal design needs to be done with adequate margin in consideration of allowable loss (Pd) in actual operation state.
7.) Use in a strong magnetic field may cause malfunction.
8.) Output Tr needs to not exceed the absolute maximum rating and ASO while using this IC. As CMOS IC and IC which has several
power sources may undergo instant flow of rush current at turn-on, attention needs to be paid to the capacitance of power source
coupling, power source, and the width and run length of GND wire pattern.
9.) This IC includes temperature protection circuit (TSD circuit). Temperature protection circuit (TSD circuit) strictly aims blockage of
IC from thermal runaway, not protection or assurance of IC. Therefore use assuming continuous use and operation after this
circuit is worked needs to not be done.
10.) As connection of a capacitor with a pin with low impedance at inspection of a set board may cause stress to IC, discharge needs
to be performed every one process. Before a jig is connected to check a process, the power needs to be turned off absolutely.
Before the jig is removed, as well, the power needs to be turned off.
11.) This IC is a monolithic IC which has P+ isolation for separation of elements and P board between elements.
A P-N junction is formed in this P layer and N layer of elements, composing various parasitic elements.
For example, a resistance and transistor are connected to a terminal as shown in the figure,
○
When GND>(Terminal A) in the resistance and when GND>(Terminal B) in the transistor (NPN), P-N junction operates
as a parasitic diode.
○
When GND>(Terminal B) in the transistor (NPN), parasitic NPN transistor operates in N layer of other elements nearby
the parasitic diode described before.
Parasitic elements are formed by the relation of potential inevitably in the structure of IC. Operation of parasitic elements can
cause mutual interference among circuits , malfunction as well as damage. Therefore such use as will cause operation of
parasitic elements like application of voltage on the input terminal lower than GND (P board) need to not be done.
Transistor (NPN)
Resistor
B
(Pin A)
P
N
P
P
P
N
N
E
C
(Pin B)
N
GND
P
P
N
N
N
P substrate
P substrate
GND
Parasitic element
GND
Parasitic element
(Pin B)
B
(Pin A)
C
E
Parasitic element
GND
GND
Adjacent other elements
Parasitic
Figure 40. Example of Simple Structure of Monolithic IC
Status of this document
The Japanese version of this document is formal specification. A customer may use this translation version only for a reference
to help reading the formal version.
If there are any differences in translation version of this document formal version takes priority.
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BD9483F,FV
●Ordering Information
B
D
9
4
8
3
F
Part Number
-
XX
Package
F:SOP
FV:SSOP
Packaging and forming specification
XX: Please confirm the formal name
to our sales.
●Marking Diagram
SSOP-B24(TOP VIEW)
SOP24(TOP VIEW)
Part Number Marking
Part Number Marking
BD9483F
D9483FV
LOT Number
LOT Number
1PIN MARK
1PIN MARK
●Physical Dimension Tape and Reel Information
SOP24
<Tape and Reel information>
15.0 ± 0.2
(MAX 15.35 include BURR)
Embossed carrier tape
Quantity
2000pcs
13
Direction
of feed
0.3MIN
5.4±0.2
7.8±0.3
24
Tape
1
E2
The direction is the 1pin of product is at the upper left when you hold
( reel on the left hand and you pull out the tape on the right hand
)
12
0.11
1.8±0.1
0.15 ± 0.1
0.4 ± 0.1
1.27
0.1
1pin
Reel
(Unit : mm)
Direction of feed
∗ Order quantity needs to be multiple of the minimum quantity.
SSOP-B24
<Tape and Reel information>
7.8 ± 0.2
(MAX 8.15 include BURR)
13
0.3Min.
1
Embossed carrier tape
Quantity
2000pcs
E2
The direction is the 1pin of product is at the upper left when you hold
( reel on the left hand and you pull out the tape on the right hand
)
12
0.15 ± 0.1
0.1
1.15 ± 0.1
Tape
Direction
of feed
5.6 ± 0.2
7.6 ± 0.3
24
0.1
0.65
0.22 ± 0.1
1pin
(Unit : mm)
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Datasheet
BD9483F,FV
●Revision History
Date
Revision
18.Sep.2012
16.Oct.2012
001
002
28.Nov.2013
003
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TSZ22111・15・001
Changes
New Release
p.7 Item arrangement of Typical Performance Curves
p.5 1.3 Pin Descriptions In/Out
GATE1:In→Out
p.13 Diagram of start-up sequence SS=0.1V → SS=0.4V
p.13 Explanation of start-up sequence SS=0.1V → SS=0.4V(typ)
p.20 3.7.1 diagram SS 0.1V → 0.4V
p.20 3.7.1 explanation(*3) less than 0.1V → less than 0.4V(typ)
p.21 3.7.2 diagram SS 0.1V → 0.4V
p.21 3.7.2 explanation (*2) less than 0.1V → less than 0.4V(typ)
p.23 3.7.4 diagram SS 0.1V → 0.4V
p.25 3.7.6 diagram SS 0.1V → 0.4V
p.26 3.7.7 diagram SS 0.1V → 0.4V
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Notice
Precaution on using ROHM Products
1.
Our Products are designed and manufactured for application in ordinary electronic equipments (such as AV equipment,
OA equipment, telecommunication equipment, home electronic appliances, amusement equipment, etc.). If you
(Note 1)
, transport
intend to use our Products in devices requiring extremely high reliability (such as medical equipment
equipment, traffic equipment, aircraft/spacecraft, nuclear power controllers, fuel controllers, car equipment including car
accessories, safety devices, etc.) and whose malfunction or failure may cause loss of human life, bodily injury or
serious damage to property (“Specific Applications”), please consult with the ROHM sales representative in advance.
Unless otherwise agreed in writing by ROHM in advance, ROHM shall not be in any way responsible or liable for any
damages, expenses or losses incurred by you or third parties arising from the use of any ROHM’s Products for Specific
Applications.
(Note1) Medical Equipment Classification of the Specific Applications
JAPAN
USA
EU
CHINA
CLASSⅢ
CLASSⅡb
CLASSⅢ
CLASSⅢ
CLASSⅣ
CLASSⅢ
2.
ROHM designs and manufactures its Products subject to strict quality control system. However, semiconductor
products can fail or malfunction at a certain rate. Please be sure to implement, at your own responsibilities, adequate
safety measures including but not limited to fail-safe design against the physical injury, damage to any property, which
a failure or malfunction of our Products may cause. The following are examples of safety measures:
[a] Installation of protection circuits or other protective devices to improve system safety
[b] Installation of redundant circuits to reduce the impact of single or multiple circuit failure
3.
Our Products are designed and manufactured for use under standard conditions and not under any special or
extraordinary environments or conditions, as exemplified below. Accordingly, ROHM shall not be in any way
responsible or liable for any damages, expenses or losses arising from the use of any ROHM’s Products under any
special or extraordinary environments or conditions. If you intend to use our Products under any special or
extraordinary environments or conditions (as exemplified below), your independent verification and confirmation of
product performance, reliability, etc, prior to use, must be necessary:
[a] Use of our Products in any types of liquid, including water, oils, chemicals, and organic solvents
[b] Use of our Products outdoors or in places where the Products are exposed to direct sunlight or dust
[c] Use of our Products in places where the Products are exposed to sea wind or corrosive gases, including Cl2,
H2S, NH3, SO2, and NO2
[d] Use of our Products in places where the Products are exposed to static electricity or electromagnetic waves
[e] Use of our Products in proximity to heat-producing components, plastic cords, or other flammable items
[f] Sealing or coating our Products with resin or other coating materials
[g] Use of our Products without cleaning residue of flux (even if you use no-clean type fluxes, cleaning residue of
flux is recommended); or Washing our Products by using water or water-soluble cleaning agents for cleaning
residue after soldering
[h] Use of the Products in places subject to dew condensation
4.
The Products are not subject to radiation-proof design.
5.
Please verify and confirm characteristics of the final or mounted products in using the Products.
6.
In particular, if a transient load (a large amount of load applied in a short period of time, such as pulse. is applied,
confirmation of performance characteristics after on-board mounting is strongly recommended. Avoid applying power
exceeding normal rated power; exceeding the power rating under steady-state loading condition may negatively affect
product performance and reliability.
7.
De-rate Power Dissipation (Pd) depending on Ambient temperature (Ta). When used in sealed area, confirm the actual
ambient temperature.
8.
Confirm that operation temperature is within the specified range described in the product specification.
9.
ROHM shall not be in any way responsible or liable for failure induced under deviant condition from what is defined in
this document.
Precaution for Mounting / Circuit board design
1.
When a highly active halogenous (chlorine, bromine, etc.) flux is used, the residue of flux may negatively affect product
performance and reliability.
2.
In principle, the reflow soldering method must be used; if flow soldering method is preferred, please consult with the
ROHM representative in advance.
For details, please refer to ROHM Mounting specification
Notice - GE
© 2014 ROHM Co., Ltd. All rights reserved.
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Datasheet
Precautions Regarding Application Examples and External Circuits
1.
If change is made to the constant of an external circuit, please allow a sufficient margin considering variations of the
characteristics of the Products and external components, including transient characteristics, as well as static
characteristics.
2.
You agree that application notes, reference designs, and associated data and information contained in this document
are presented only as guidance for Products use. Therefore, in case you use such information, you are solely
responsible for it and you must exercise your own independent verification and judgment in the use of such information
contained in this document. ROHM shall not be in any way responsible or liable for any damages, expenses or losses
incurred by you or third parties arising from the use of such information.
Precaution for Electrostatic
This Product is electrostatic sensitive product, which may be damaged due to electrostatic discharge. Please take proper
caution in your manufacturing process and storage so that voltage exceeding the Products maximum rating will not be
applied to Products. Please take special care under dry condition (e.g. Grounding of human body / equipment / solder iron,
isolation from charged objects, setting of Ionizer, friction prevention and temperature / humidity control).
Precaution for Storage / Transportation
1.
Product performance and soldered connections may deteriorate if the Products are stored in the places where:
[a] the Products are exposed to sea winds or corrosive gases, including Cl2, H2S, NH3, SO2, and NO2
[b] the temperature or humidity exceeds those recommended by ROHM
[c] the Products are exposed to direct sunshine or condensation
[d] the Products are exposed to high Electrostatic
2.
Even under ROHM recommended storage condition, solderability of products out of recommended storage time period
may be degraded. It is strongly recommended to confirm solderability before using Products of which storage time is
exceeding the recommended storage time period.
3.
Store / transport cartons in the correct direction, which is indicated on a carton with a symbol. Otherwise bent leads
may occur due to excessive stress applied when dropping of a carton.
4.
Use Products within the specified time after opening a humidity barrier bag. Baking is required before using Products of
which storage time is exceeding the recommended storage time period.
Precaution for Product Label
QR code printed on ROHM Products label is for ROHM’s internal use only.
Precaution for Disposition
When disposing Products please dispose them properly using an authorized industry waste company.
Precaution for Foreign Exchange and Foreign Trade act
Since our Products might fall under controlled goods prescribed by the applicable foreign exchange and foreign trade act,
please consult with ROHM representative in case of export.
Precaution Regarding Intellectual Property Rights
1.
All information and data including but not limited to application example contained in this document is for reference
only. ROHM does not warrant that foregoing information or data will not infringe any intellectual property rights or any
other rights of any third party regarding such information or data. ROHM shall not be in any way responsible or liable
for infringement of any intellectual property rights or other damages arising from use of such information or data.:
2.
No license, expressly or implied, is granted hereby under any intellectual property rights or other rights of ROHM or any
third parties with respect to the information contained in this document.
Other Precaution
1.
This document may not be reprinted or reproduced, in whole or in part, without prior written consent of ROHM.
2.
The Products may not be disassembled, converted, modified, reproduced or otherwise changed without prior written
consent of ROHM.
3.
In no event shall you use in any way whatsoever the Products and the related technical information contained in the
Products or this document for any military purposes, including but not limited to, the development of mass-destruction
weapons.
4.
The proper names of companies or products described in this document are trademarks or registered trademarks of
ROHM, its affiliated companies or third parties.
Notice - GE
© 2014 ROHM Co., Ltd. All rights reserved.
Rev.002
Datasheet
General Precaution
1. Before you use our Pro ducts, you are requested to care fully read this document and fully understand its contents.
ROHM shall n ot be in an y way responsible or liabl e for fa ilure, malfunction or acci dent arising from the use of a ny
ROHM’s Products against warning, caution or note contained in this document.
2. All information contained in this docume nt is current as of the issuing date and subj ect to change without any prior
notice. Before purchasing or using ROHM’s Products, please confirm the la test information with a ROHM sale s
representative.
3.
The information contained in this doc ument is provi ded on an “as is” basis and ROHM does not warrant that all
information contained in this document is accurate an d/or error-free. ROHM shall not be in an y way responsible or
liable for an y damages, expenses or losses incurred b y you or third parties resulting from inaccur acy or errors of or
concerning such information.
Notice – WE
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