BD9479FV-GE2 [ROHM]
Display Driver, PDSO40;
| 型号： | BD9479FV-GE2 |
| 厂家： | 
ROHM |
| 描述： | Display Driver, PDSO40 光电二极管 |
| 文件： | 总29页 (文件大小：1128K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Datasheet
LED Drivers for LCD Backlights
White LED Driver for large LCD
Panels (DCDC Converter type)
BD9479FV
●General Description
●Features
BD9479FV is a high efficiency driver for white LEDs
and designed for large LCDs. This IC is built-in a boost
DCDC converters that employ an array of LEDs as the
light source. BD9479FV has some protect function
against fault conditions, such as the over-voltage
protection (OVP), the over current limit protection of
DCDC (OCP), the short circuit protection (SCP), the
open detection of LED string. Therefore BD9479FV is
available for the fail-safe design over a wide range
output voltage.
8ch LED constant current driver (external PNP Tr
Type)
Maximum LED setting current 500mA (VREF pin
setting)
Build-in DC/DC converter
Analog Dimming (Linear) function
Individual channel PWM Dimming function
LED protection function (Open Short protection)
[PWM-independent Type]
Output short protection (OVP)
Built-in Timer latch function (CP)
Built-in under voltage Lockout function (UVLO)・over
voltage protection (OVP)
●Key Specification
Operating power supply voltage range: 9.0V to 35.0V
Built-in FAIL indication function
Built-in OVP voltage Feedback function
Built-in PWM-independent soft start circuit
SSOP-B40 Package
Oscillator frequency:
Operating Current:
Operating temperature range:
150kHz (RT=100kΩ)
8.7mA (typ.)
-40℃ to +85℃
●Applications
TV, Computer Display, Notebook, LCD Backlighting
●Package
SSOP-B40:
W(Typ.) D(Typ.) H(Max.)
13.6mm x 7.80mm x 1.80mm
Pin Pitch:
0.65mm
●Typical Application Circuit
Figure 1. SSOP-B40
Figure 2. Typical Application Circuit
○Product structure：Silicon monolithic integrated circuit ○This product is not designed protection against radioactive rays
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●Absolute maximum ratings (Ta=25℃)
Parameter
Symbol
Ratings
36
Unit
V
Power supply voltage
VCC
BS1-8
BS1-8 terminal voltage
40
V
OVP, STB, PWM1-8,VREF,UVLO terminal voltage
OVP, STB, PWM1-8,VREF,UVLO
20
V
REG50, N, CS, CP, LSP, CL1-8, FB, SS, RT
terminal voltage
REG50, N, CS, CP, LSP, CL1-8,
FB, SS, RT
7
V
Power dissipation (SSOP-B40)*1
Operating temperature range
Storage temperature range
Junction temperature
Pd
1.125(Note1)
-40 to +85
-55 to +150
150
W
℃
℃
℃
Ta(opr)
Tstg
Tjmax
(Note1) SSOP-B40 package at Ta25C or higher, de-rating power rating by 9.0mW/C(70.0mm x 70.0mm x1.6mm with 1-layer board)
●Operating Ratings (Ta = 25℃)
Parameter
Symbol
VCC
Limits
Unit
V
VCC supply voltage
9.0 to 35.0
0.6 to 3.0
0.3 to 3.0
100 to 800
0.05 to 20
Analog Dimming setting (VREF Pin) range
LSP setting voltage range
VREF
VLSP
FCT
V
V
DC/DC oscillation frequency
kHz
kHz
PWM pin input frequency range
F_PWM
Above operating condition are the constants of IC itself. Please pay attention at the actual set.
●Recommended external component range
Parameter
VCC pin connecting capacity
DC/DC frequency setting resistant
REG50 pin connecting capacity
Soft start setting capacity
Symbol
Limits
Unit
uF
kΩ
uF
uF
uF
CVCC
RRT
1 to 100
18.75 to 150
1.0 to 10
CREG50
CSS
0.001 to 1.0
0.001 to 1.0
Timer Latch setting capacity
CCP
Above operating condition are the constants of IC itself. Please pay attention at the actual set.
●Pin Configuration
●Marking diagram and physical dimension
Marking
BD9479FV
1PIN MARK
LOT No
Figure 4. Physical Dimension
SSOP-B40
Figure 3. Pin Configuration
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●Electrical Characteristics (Unless otherwise noted, Ta = 25oC, VCC=24V)
Limit
Parameter
[Whole Device]
Symbol
Unit
Condition
Min.
Typ.
Max.
－
－
Operation current
ICC
IST
8.7
12
14.0
24
mA STB=3V, PWM1-8=0V
Standby current
uA
STB=0V
[UVLO Block]
Operation Voltage （VCC）
Hysteresis Voltage （VCC）
Operation Voltage （UVLO）
VUVLO_VCC
VUHYS_VCC
VUVLO
6.5
150
2.91
170
7.5
300
3.00
210
8.5
600
3.09
250
V
mV
V
VCC=SWEEP UP
VCC=SWEEP DOWN
UVLO=SWEEP UP
UVLO=SWEEP DOWN
Hysteresis Voltage（UVLO）
VUHYS
mV
[DC/DC Block]
Error amp Base Voltage
Oscillation frequency
VEAMP
0.55
0.60
0.65
V
BSx pin, VREF=0.9V
FCT
NMAX_DUT
Y
142.5
150.0
157.5
kHz
RT=100kΩ
N pin MAX DUTY output
N pin source ON resistor
N pin sink ON resistor
RT pin Voltage
90
0.5
95
1
99
2
%
Ω
RT=100kΩ
RNSO
RNSI
0.5
1
2
Ω
VRT
1.00
-2.4
3.6
1.50
-2.0
4.0
-100
100
0.40
2.00
-1.6
4.4
-90
115
0.45
V
RT=100kΩ
SS pin source current
Soft start ended Voltage
FB pin source current
FB pin sink current
ISSSO
VSS_ED
IFBSO
IFBSI
uA
V
-110
85
uA
uA
V
Over current detect Vlotage
VCS
0.35
[DC/DC Protection Block]
CP pin source current
CP pin detect Voltage
OVP High detect voltage
OVP Feedback Voltage
ICPSO
VCP
-2.4
2.375
2.137
2.375
0.14
-2.0
2.500
2.250
2.500
0.20
-1.6
2.625
2.363
2.625
0.30
uA
V
VOVPH
VOVPFB
VOVPL
V
V
OVP Low detect Voltage
V
[LED PNP Driver Block]
CL pin current setting Voltage
CL pin current setting Voltage
(Analog MAX)
VRCL
295.5
-3%
300.0
1.0
304.5
+3%
mV
V
VREF=0.9V
VRCLMAX
VREF max=3.0V
CL pin current setting Voltage
(Analog MIN)
VRCLMIN
RBS
-3%
55
200.0
80
+3%
120
1.0
mV
Ω
VREF min=0.6V
PWMx=High, VCL=Low
VREF=1V
PNP Driver output sink resistor
VREF pin input current
IVREF
-1.0
0.0
uA
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●Electrical Characteristics (Unless otherwise noted, Ta = 25oC, VCC=24V)
Limit
Parameter
Symbol
Unit
Condition
Min.
Typ.
Max.
[LED protection Block]
LED OPEN Detect Voltage
VOPEN
0.05
0.10
0.15
V
BSx=SWEEP DOWN
BSx=SWEEP UP,
LSP=OPEN
LED SHORT Detect Voltage
CL pin Detect Voltage
VLSP
VCLLVP
RULSP
RDLSP
8.5
0.05
1260
540
9.0
0.10
2100
900
9.5
V
V
0.15
3180
1620
LSP pin pull high resistor
kΩ
kΩ
LSP=0V
LSP=3V
LSP pin pull down resistor
[REG50 Block]
REG50 output Voltage
REG50
4.95
5
5.00
-
5.05
-
V
Io=-5mA
※DCDC block consumption
is neglected.
REG50 maximum output current
|IREG50|
mA
[STB Block]
STB pin HIGH Voltage
STB pin LOW Voltage
STBH
STBL
RSTB
2.0
-0.3
0.5
-
-
VCC
0.8
V
V
STB=SWEEP UP
STB=SWEEP DOWN
STB=3.0V
STB pin Pull Down resistor
1.0
2.0
MΩ
[PWM input Block]
PWMx pin High detect voltage
PWMx pin Low detect voltage
PWMx pin Pull Down resistor
[FAIL Block(OPEN DRAIN)]
PWM_H
PWM_L
RPWM
2.0
-0.3
0.5
-
-
18
0.8
2.0
V
V
PWM=SWEEP UP
PWM=SWEEP DOWN
PWM=3.0V
1.0
MΩ
FAIL pin Ron
FAIL pin Leakage current
RFAIL
ILFAIL
30
50
85
Ω
-1.0
0.0
1.0
uA
FAIL=36V
(This product is not designed to be radiation-proof.)
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●Pin Descriptions
Pin No
1
Pin Name
In/Out
Out
Out
-
Function
5V regulator output for N output pin
DC/DC switching output pin
Power GND
Rating [V]
-0.3 ~ 7
-0.3 ~ 7
-
REG50
N
2
3
PGND
CS
4
In
DCDC external NMOS current monitor pin
Overvoltage protection detection pin
Timer Latch setting pin
-0.3 ~ 7
-0.3 ~ 20
-0.3 ~ 7
-0.3 ~ 7
-0.3 ~ 20
-0.3 ~ 40
-0.3 ~ 40
-0.3 ~ 40
-0.3 ~ 40
-0.3 ~ 40
-0.3 ~ 40
-0.3 ~ 40
-0.3 ~ 40
-0.3 ~ 20
-0.3 ~ 20
-0.3 ~ 20
-0.3 ~ 20
-0.3 ~ 20
-0.3 ~ 20
-0.3 ~ 20
-0.3 ~ 20
-0.3 ~ 7
-0.3 ~ 7
-0.3 ~ 7
-0.3 ~ 7
-0.3 ~ 7
-0.3 ~ 7
-0.3 ~ 7
-0.3 ~ 7
-0.3 ~ 20
-0.3 ~ 7
-0.3 ~ 7
-0.3 ~ 7
-0.3 ~ 20
-
5
OVP
CP
In
6
Out
In
7
LSP
LED short voltage setting pin
Enable pin
8
STB
BS1
In
9
In
PNP Tr Base connecting pin１
PNP Tr Base connecting pin２
PNP Tr Base connecting pin３
PNP Tr Base connecting pin４
PNP Tr Base connecting pin５
PNP Tr Base connecting pin６
PNP Tr Base connecting pin７
PNP Tr Base connecting pin８
Dimming signal input pin１
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
BS2
In
BS3
In
BS4
In
BS5
In
BS6
In
BS7
In
BS8
In
PWM1
PWM2
PWM3
PWM4
In
In
Dimming signal input pin２
In
Dimming signal input pin３
In
Dimming signal input pin４
In
Dimming signal input pin５
PWM5
PWM6
PWM7
PWM8
CL8
In
Dimming signal input pin６
In
Dimming signal input pin７
In
Dimming signal input pin８
Out
Out
Out
Out
Out
Out
Out
Out
In
PNP Tr collector ・current detection pin８
PNP Tr collector ・current detection pin７
PNP Tr collector ・current detection pin６
PNP Tr collector ・current detection pin５
PNP Tr collector ・current detection pin４
PNP Tr collector ・current detection pin３
PNP Tr collector ・current detection pin２
PNP Tr collector ・current detection pin１
LED voltage setting pin
CL7
CL6
CL5
CL4
CL3
CL2
CL1
VREF
FB
In/Out
Out
Out
In
DCDC phase-compensation pin
Soft Start pin
SS
DCDC frequency setting resistor connection pin
Under voltage Lockout protection pin
Analog GND
RT
UVLO
AGND
FAIL
VCC
-
Out
-
Error detection output pin
-0.3 ~ 36
-0.3 ~ 36
Power supply pin
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●Pin ESD Type
REG50 / N / PGND / CS
REG50
OVP
STB
VREF
RT
N
100k
PGND
CS
CP
LSP
PWM(1-8)
SS
BS(1-8) / CL(1-8)
FB
Figure 5-1. Pin ESD Type
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UVLO
FAIL
Figure 5-2. Pin ESD Type
●Block Diagram
Figure 6. Block Diagram
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●Typical Performance Curve
Figure 8. REG50[V] vs. VCC[V]
Figure 7. Operating Current (ICC) [mA] vs. VCC[V]
15
13
11
9
7
6
5
4
3
2
7
5
3
9
13
17
21
25
29
33
9
13
17
21
25
29
33
VCC [V]
VCC [V]
Figure 9. CL1 Voltage (VRCL1) [V] vs. VREF [V]
Figure 10. N Frequency [MHz] vs. R_RT [MΩ]
2
10
1
1.6
1.2
0.8
0.4
0
0.1
0.01
0.015
0.035
0.055
0.075
0.095
0.115
0.135
0.6
1.1
1.6
2.1
2.6
VREF [V]
RRT [MΩ]
Figure 11. CL1 Voltage (VRCL1) [V] vs. Temp [℃]
Figure 12. FB Current (IFB) [uA] vs. VBS1 [V]
160
120
80
400
380
360
340
320
300
280
260
240
220
200
40
0
-40
-80
-120
-160
0
0.2
0.4
0.6
0.8
1
1.2
1.4
-40
-20
0
20
40
60
80
VBS1 [V]
TEMP [°C]
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●Pin Function
○Pin 1: REG50
The REG pin is used in the DC/DC converter driver block to output 5V power. The maximum operating current is 5mA.
Using the REG pin at a current higher than 5mA can affect the N pin output pulse, causing the IC to malfunction and
leading to heat generation of the IC itself. To avoid this problem, it is recommended to make load setting to the minimum
level.
○Pin 2:N
The N pin is used to output power to the external NMOS gate driver for the DC/DC converter in the amplitude range of
approx. 0 to 5V. Frequency setting can be made with a resistor connected to the RT pin. For details of frequency setting,
refer to the description of the ＜RT pin＞.
○Pin 3: PGND
The PGND pin is a power ground pin for the driver block of the N output pin.
○Pin 4: CS
CS pin is current detect for DC/DC current mode inductor current control pin.
Current flowing through the inductor is converted into voltage by the current sensing resistor RCS connected to the CS
pin and this voltage is compared with voltage set with the error amplifier to control the DC/DC output voltage.
The CS pin also incorporates the overcurrent protection (OCP) function. If the CS pin voltage reaches 0.4V (Typ.) or
more, switching operation will be forcedly stopped.
In order to prevent the malfunction while OCP occurred in BD9479FV,it equipped with mask function.It mask OCP signal
within 200ns interval after N driver is outputted.
Pin 5: OVP
The OVP pin is an input pin for overvoltage protection and short circuit protection of DC/DC output voltage.When voltage
of it over 2.25V or higher,CP pin start to charge.When it over 2.5V(typ),it will control FB pin.When OVP pin voltage is
near 2.5V,DCDC output feedback will controlled by OVP pin voltage.
When OVP pin voltage<0.2V (typ.) or lower,short circuit protection (SCP) function is activated, and output of Gate driver
will become low immediately.
Pin 6: CP
CP pin which sets the time from detection of abnormality until shutdown (Timer latch).It charges constant current
of 2.0uA to capacitor externally connected with CP pin and shuts down when it exceeds 2.5V(Typ.).
Pin 7: LSP
LED Short detect voltage setting pin.When LSP=OPEN, LSP pin voltage is 0.9V( typ), the BSx pin of LED SHORT detect
voltage is set to 9V.
The 10 times of LSP pin voltage is the BSx pin LED SHORT protection detect voltage.
Please set LSP pin input voltage range from 0.3V～3.0V.
Pin 8 :STB
ON/OFF setting pin and allowed for use to reset the IC from shutdown.
※The IC state is switched (i.e., The IC is switched between ON and OFF state) according to voltages input in the STB
pin. Avoid using the STB pin between two states (0.8 to 2.0V).
Pin 9-16 :BS1-BS8
LED DRIVER output pin.Please connect to Base Terminal of external PNP Tr.
Pin 17-24 :PWM1 – PWM8
ON/OFF terminal of LED driver pin.It inputs PWM dimming signal directly to adjust output DUTY dimming.
High/Low level of PWM terminal is shown as follows:
State
LED ON state
LED OFF state
PWM Voltage
PWM= 2.0V~5.0V
PWM= －0.3V～0.8V
Pin 25-32 : CL8 – CL1
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LED current detect pin.By monitoring voltage of CLx pin to detect LED current.Please connect resistor to collector pin of
external PNP Tr.
Pin 33 : VREF
LED current setting pin.1/3(typ) of applied voltage to VREF pin will be LED current
feedback voltage, 2/3(typ.) of its voltage will be DCDC feedback voltage（the
lowest BSx pin feedback voltage）.
Basically, because hi accuracy of resistor divider is inputted to VREF pin
externally, the IC internally will be OPEN（High Impedance）state.Please use
external power to design it.It cannot be used in OPEN state.
Pin 34 : FB
Current mode control DC/DC converter error amplifier output pin.By monitoring
voltage of BS（1～8）pin, the highest Vf of LED column will set 2/3(typ.) of applied VREF voltage to BS pin voltage to
control inductor current.
The phase compensation setting has described separately.
In addition, PWM pin will become High Impedance when all PWM signals are in low state, and will maintain FB voltage.
Pin 35 : SS
The SS pin is used to set the soft start time and duty for soft start duration.SS pin normally sources 2.0uA (Typ.) of
current.When STB pin become high, it wait for in any one PWMx signal from low to high.In start-up duration, SS will not
charge because all PWMx pin are in low state.
The BD9479FV has a built-in soft start startup circuit independent of PWM light modulation, and thereby raises FB
voltage as SS pin voltage rises independent of the duty cycle range of PWM light modulation.Please pay attention to
overshoot problem will occur while low duty is inputted to IC IN start-up duration.
Pin 36 : RT
RT sets charge/discharge current determining frequency inside IC.
Only a resistor connected to RT determines saw-tooth wave frequency inside IC.
When RT=100,Frequency=150kHz(typ.).
For calculation example, please refer to section in “3.2.2 – DC/DC drive frequency setting”.
Pin 37 : UVLO
UVLO pin of the coil of step-up DC/DC converter and the power for external NMOSFET.
At 3.0 V (typ.) or higher, IC starts step-up operation and stops at 2.79V or lower (typ.). (It is not shutdown of IC.)
Pin 38 : AGND
GND pin for analog system inside IC.
Pin 39 : FAIL
FAIL signal indication output pin (Open Drain).In normal operation, FAIL pin is OPEN when STB=Low.When an
abnormality is detected, CP starts to charge to external capacitance and then shutdown IC while it reach 2.5V or
higher.NMOS ON is 50 ohm(typ.）when IC is shutdown.When VCC voltage is insufficient or UVLO pin voltage is lower,
FAIL pin is also in open state.
State
FAIL Output
Normal, STB=Low,
（Under abnormality detection）
OPEN
Abnormality (shutdown),
UVLO is detected
GND Level
(50 ohm typ.)
Pin 40 : VCC
Power source pin of IC, which should be input in the range of 9 – 35 V.
Operation starts when VCC is 7.5V (TYP.) or higher and shuts down when VCC is 7.2 V (TYP.).
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●LED current setting (VREF pin, CLx pin)
Please decide VREF pin input voltage first.When Analog dimming is performed,
please be noted that VREF pin input voltage range is (0.6V ～ 3.0V), and decide the
input voltage in normal operation.Basically, if VREF pin voltage is high, it will cause
power dissipation of external PNP Tr become high, so it is preferred to set the VREF pin
voltage lower.
Later, VREF＝0.9V will be set as basic.For example if you create 0.9V from REG50, it
is possible to use resistive divider by setting 82kohm and 18kohm.
In BD9479FV, the LED current detection is performed by CLx pin.CLx pin is controlled
so that the voltage of 1/3V(typ.) of VREF voltage.If VREF=0.9V, CLx=0.3V to control
external PNP Tr.Therefore,if 「RCL」 is set as a resistance which between CLx pin and
GND, and VREF pin voltage is set as 「VVREF」, LED current 「ILED」can be calculated as
below.
VVREF [V ]
RCL [ohm]
ILED [A]3
For current setting, set at each channel.For this reason, in 1ch～4ch and 5ch～8ch, it
is possible to change current by setting 「RCL」value.
●DCDC operation frequency setting (RT Pin)
The operation frequency of DCDC output is set by resistance which connected to RT pin.
○The relationship between operation and RT resistance (ideal)
Here, fsw＝DCDC converter oscillation frequency[kHz]
15000
RRT
[k]ꢀ
Above is an ideal equation which do not putted with correction terms。
For accurate frequency setting, please confirm on the real system。
but, the frequency setting range is 100kHz～800kHz。
fSW [kHz]
Ideal
【Setting Example】
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If DCDC frequency is set to be 200kHz, RRT as below:
15000
15000
RRT
75 [k] ꢀ
fsw[kHz] 200[kHz]
●Maximum DCDC output Voltage
In BD9479FV, the voltage of BSx pin is depending on VREF pin voltage.The maximum voltage of VREF pin（VREF＝
3.0V）, the voltage of BSx pin will become 2.0V（2/3 of VREF voltage ）.
The maximum voltage of DCDC output will have be vary with 1.6V while Analog dimming is performed (2/3 of 3.0V -
0.6V).
●Soft Start Time setting (SS Pin)
The start-up time of DCDC output is adjusted by condenser which connected to SS pin.its performs constant current
charge of 2.0uA to the external capacitor connected with SS pin, and the each protection and CP charge function will not
activated before SS pin reaches to 4.0V.
（soft start time set here is mask time of CP charge, please pay attention to it is different from the time to stabilize DCDC
output.The time to stabilize DCDC output is largely depending on step-up ratio and load condition.）
The soft start time「TSS」, and SS pin external condenser「CSS」 can be calculated as below.
TSS [sec] 2.0106 [A]
CSS [F]
4.0[V ]
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●Start-up and soft start (SS) capacitance setting
The following describes the start-up sequence of this IC.
5V
VOUT
SS
Q
D
PWM
SLOPE
SS
COMP
N
DRIVER
SS=FB
Circuit
BSx
CLx
PWM
LED_DRIVER
○Description of start-up squenc
①Set STB from Low to Hig
②System will be activated while PWM=H.SS start to charge.
At this time, a circuit in which SS pin voltage for slow start becomes equal to FB pin voltage operates to equalize the
FB pin and SS pin voltages regardless of whether the PWM pin is set to Low or High l eve.
③Since the FB pin and SS pin reach the lower limit of the internal sawtooth wave of the IC, the DC/DC converter
operates to start VOUT voltage rising.
④The Vout voltage continues rising to reach a voltage at which LED current starts flowing.
⑤When the LED current reaches the amount of current, isolate the FB circuit from the SS circuit. With this, the
startup operation is completed.
⑥After that, normal operation is controlled by following the feedback voltage of LED pins.
If the SS pin voltage reaches 4V or higher, the LED protection function will be activated to forcedly end the SS and FB
equalizing circuit.
○SS capacitance setting procedure
As mentioned above, this IC stops DC/DC converter when the PWM pin is set to Low level.conducts step-upoperation
only in the section in which the PWM pin is maintained at High level. Consequently, setting the PWM duty cycle to the
minimum will extend the start-up time.In addition, start-up time also varies with application of output capacitance selection,
LED current, output voltage, and others.
Start-up time at minimum duty cycle can be approximated according to the following method.First, measure the start-up
time of VOUT with a 100% DUTY and take this value as Trise_100.The startup time “Trise_min” for the relevant
application with the minimum duty cycle is given by the following equation.
However, this calculation method is just for approximation, use it only as a reference.
Please set a time「TDCDCSS 」 during which the SS pin voltage reaches the FB pin voltage longer than this star-tup.
Assuming that the FB pin voltage is VFB, the time is given by the following equation:
T
rise_100[sec]
Trise_ min
[sec]
Min_ Duty[ratio]
As a result, it is recommended to make SS capacitance setting so that “TDCDCSS” will be longer than “Trise_min”
CSS [F]VFB[V]
TDCDCSS
[sec]
2[A]
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●UVLO setting procedure
It is UVLO function for the DC/DC converter power supply.If its voltage reaches 3.0V (Typ.) or higher, the IC will start
step-up operation. If it reaches 2.79V (Typ.) or less, the IC will stop the step-up operation.The UVLO pin is the high
impedance type and involves no pull-down resistor, resulting in unstable operation in the open-circuited state. Avoid this
problem, please make sure to input voltage by using resistor divider or otherwise.
If the VIN pin voltage to be detected is set by resistor divider R1 and R2 as described below, resistance setting will be
made by the following equation:
○UVLO detection setting equation
Assuming that a voltage VIN decreasing, UVLO is “VINDET”, R1 and R2 setting will be made by
following equation:
the
(VINDET [V] 2.79[V])
R1 R2[k]
[k]
2.79[V]
○UVLO release voltage setting equation
When R1 and R2 setting is determined by the equation shown above,
UVLO release voltage will be given by the following equation:
(R1[k] R2[k])
VINCAN 3.0V
[V]
R2[k]
【Setting example】
Assuming that the VIN input voltage is 24V, UVLO detection voltage is 17.36V, and R2 resistance is 13kΩ, R1
resistance setting is decided by the following equation:
(VINDET [V] 2.79[V])
2.79[V]
(17.36[V] 2.79[V])
2.79[V]
R1 R2[k]
13[k]
68[k]
Furthermore, VINCAN can be calculated as below equation when R1(68kΩ), R2(13kΩ) are decided above
(R1[k] R2[k])
R2[k]
13[k] 68[k]
13[k]
VINCAN 3.0[V]
3.0[V]
[V]ꢀ18.69[V]
*For the selection of DC/DC components, please also consider the inaccuracy of each componentts.
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●OVP/SCP setting procedure (OVP Pin)
VOUT
There are two type of over voltage protection in
BD9479FV.The one is OVP detection, another is OVP
feedback.
Basically, the CP pin start to charge when OVP pin voltage
higher than 2.25V.when OVP pin voltage is between 2.25V with
2.5V, the operation of DCDC is continued and CP start to
charge only.When OVP pin voltage reaches 2.5V, until then
the feedback voltage control will be switch from BSｘ pin to
OVP pin（please refer to below figure）.For this reason, its
prevent the voltage of OVP pin become 2.5V or higher when
LED column has closed with impendence causing the rising of
DCDC voltage.
R3
C1
R1
R2
FB
OVP
-
+
2.5V
+
-
2.25V
-
+
0.2V
OVP pin is also used for feedback control, please noted that not only the resistor divider of monitoring normal voltage,
but also the external CR of phase compensation is needed.Basically, it is needed to aligned with the feedback gain to LED
driver section.If R3 is same as R2（1k～10kΩ）, the breakdown voltage of C which connected to it should be confirmed first
（And in series of two or more if necessary）, about 0.1uF is assumed and need to be decided in real system.
The following section describes setting procedures to be followed if the VOUT pin voltage to be detected is setby the
use of resistive dividers R1 and R2.
○OVP detection setting equation
Assuming that voltage of VOUT rising abnormally and detecting OVP is “VOVPDET”, R1 and R2 setting will be made by
the following equation.
（R2 will also affect phase compensation of feedback section, please set 1k ～ 10kΩ as basic.）
(VOVPDET [V]2.25[V])
R1 R2[k]
[k]
2.25[V]
○OVP feedback setting equation
The OVP feedback 「VOVPFEED」 voltage is calculated as below when R1,R2 is decided above:
(R1[k] R2[k])
VOVP
2.5V
[V]
FEED
R2[k]
○SCP detection setting
The SCP setting「VSCPDET」 voltage is calculated as below when R1,R2 is decided above:
(R1[k] R2[k])
VSCP 0.2V
[V]
DET
R2[k]
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●LED short voltage setting(BSx pin, LSP pin)
The detection voltage of LED short when BSx pin higher than 9V
while LSP pin is in OPEN state.
It is possible to change the LED short detection voltage, please
input (0.3V～3.0V) to LSP pin.
The relationship between LED short detection voltage
「VLEDshort」, and LSP pin voltage 「VLSP」 as below equation.
VLEDshort [V ]
VLSP [V ]
10
In addition, because LSP pin has split 3V of terminal resistance
inside IC.（Refer to upper right schematic）, it
will be combined resistance value of IC’s internal resistance and
connecting to external resistor.For this reason, when configure the voltage of LSP in resistor divider, it is recommended to
connect a resistor which has a little impact from internal resistance value.（Resistance is less susceptible to internal
resistor, but care must be taken because power consumption will become large.）
○LSP setting procedure
Below equation shows how to calculate the detection voltage of VLSP by using R1,R2 resistor divide which connect to
REG50 voltage.
R2[k]
(R1[k] R2[k]
VLSP REG50[V]
10 [V]ꢀ(1)
However, this equation is without considering IC resistance. If internal resistance is taken into account, the detection
voltage VLSP will be given by the following equation:
R2[k] R4[k]
REG50[V] R3 REF[V] R1[k]
VLSP
10 [V]ꢀ(2)
(R1[k] R3[k] R2 R4
R2[k] R4[k] R1[k] R3[k]
Please set R1 and R2 resistance so that a difference between resistance values found by Equations (1) and (2) will come
to approximately 2% or less as a reference.
【Setting example】
Assuming that LSP is approximated by Equation (1) in order to set LSP detection voltage to 5V, R1 comes to
45k
and R2 comes to 5k.
When calculating LSP detection voltage taking into account internal IC resistance by Equation (2), it will be given as:
5[k]900[k]
(45[k]2100[k] 5900
5[V]21003[V]45[k]
VLSP
10 5.028V[V]
5[k]900[k] 45[k] 2100[k]
The difference is given as:
5.028[V]5[V] /5[V]100 0.56%
As a result, this setting will be little affected by internal impedance.
For the selection of DC/DC components, please also consider the inaccuracy of each componentts.
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●Timer latch time (CP Pin)
The CP pin will source 2.0uA current when any abnormal problem is detected.Even is an error is detected, IC does not
stop as long as CP pin is not to 2.5V.CP pin which sets the time from detection of abnormality until shutdown (Timer latch).
CP charge time「TCP」 is set by the following equation:
TCP [sec] 2.0106 [A]
CCP [F]
2.5[V ]
●FAIL Signal
FAIL pin will change to Low when UVLO and latch occurred after CP charged.Please make sure that there is no logic
problem in module design.The breakdown voltage of this pin is 36V.
state
FAIL output
Normal, STB=Low,
（Under Abnormal detection）
OPEN
Abnormality
detected(shutdown),
UVLO detected
GND Level
(50 ohm typ.)
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●OCP setting / DCDC component current tolerance selection guide
The OCP detection function that is one of the functions of the CS pin will stop the DC/DC converter operating ifthe CS pin
voltage becomes larger than 0.4V.Consequently, it is needed to calculate a peak current flowing through the coil L and then
review the resistance of RCS.Furthermore, a current tolerance for DC/DC components should be larger than that for peak
current flowing through the coil L.The following describes the peak coil current calculation procedure, CS pin connection
resistor RCS selection procedure, and DC/DC component current tolerance selection procedure .
VOUT
L
○Peak coil current Ipeak calculation
Ripple voltage generated at the CS pin is determined by conditions
for DC/DC application components first, Assuming the conditions as
below:
VIN
IL
「output voltage=VOUT[V] 」
fsw
「LED total current=IOUT[A] 」
「DCDC input voltage=VIN[V] 」
「DCDC efficiency=η[%] 」
N
CS
Rcs
And then mean input current IIN required for the whole system is given
by the following equation.
PGND
VOUT [V] IOUT [A]
VIN [V][%]
IIN
[A]ꢀ
Further, according to drive operation with the DC/DC converter switching
frequency fsw [Hz], inductor ripple current ΔIL [A] generated at
the inductor L
(or H) is given by the following equation.
(VOUT [V ] VIN [V ]) VIN [V ]
L[H ]VOUT [V ] fSW [Hz]
ΔIL
[A]
As a result, the peak current Ipeak of IL is given by the following
equation.
IL[A]
Ipeak IIN [A]
[A](1)
2
○CS pin connection resistor RCS selection procedure
The current Ipeak flows into RCS to generate voltage.（See the
timing chart shown to the right）The voltage VCSpeak is given by the
following equation.
VCS peak Rcs Ipeak [V ]
If VCSpeak voltage reaches 0.4V, DC/DC output will
stop.Consequently, to select RCS resistance, the following condition
should be met.
Rcs Ipeak[V ] 0.4[V ]
○DC/DC component current tolerance selection procedure
Iocp current needed for OCP detection voltage CS to reach 0.4V is given by the following equation:
0.4[V ]
IOCP
[A](2)
Rcs[]
The relation among Ipeak current (Equation (1)), Iocp current (Equation (2)), and Maximum current tolerance for
component should meet the following equation.
MAX current tolerance
I peak IOCP
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DC/DC application components including FETs, inductors, and diodes should be selected so that the Equation
shown above will be met.
In addition, it is recommended to use continuous mode in DCDC application.And the lower limit value of coil ripples
current Imin so as to meet the following equation:
IL[A]
I min I IN [A]
[A] 0
2
A failure to meet this condition is referred to as discontinuous mode and this failure may result in an inadequate rise in
output voltage.
【Setting example】
Output=VOUT[V]=40V
LED 1ch current=120mA, total LED current IOUT[A]=120mA×8ch=0.96A
DCDC input voltage=VIN [V] =24V
DCDC efficiency=η[%]=90%
Mean input current IIN required for the whole system is given by the following equation:
VOUT [V] IOUT [A]
VIN [V][%]
40[V]0.96[A]
24[V] 0.9
IIN [A]
ꢀ
1.78 [A]
DCDC switching frequency=fsw[Hz]=200kHz
Inductor [H]=33μH
The inductor ripple current ΔIL [A] is given by the following equation:
(VOUT [V ] VIN [V ]) VIN [V ]
L[H ]VOUT [V ] fSW [Hz]
(40[V ] 24[V ]) 24[V ]
33106 [H ] 40[V ] 200 103[Hz]
ΔIL
ꢀ
1.45 [A]
As a result, the peak current Ipeak of IL is given by the following equation.
IL[A]
1.45[A]
Ipeak IIN [A]
[ꢀA] 1.78[A]
2.51[A]
2
2
When RCS resistance is set to 0.1ohm, the VCS peak voltage will be given by the following equation:
VCS peak Rcs Ipeak 0.1[] 2.51[A] 0.251 [V ] 0.4 [V ]
Consequently, the result meets the condition.
Furthermore, IOCP current at which OCP is detected is given by the following equation:
0.4[V ]
IOCP
4.0 [A]
0.1[]
So must select the component of about 5A in order to meet the above result.
I peak IOCP
2.51[A] 4.0 [A] 5.0 [A]
Particularly, To select DC/DC components, give consideration to IC variations as well as individual component
variations, and then conduct thorough verification on practical systems..
The lower limit value of coil ripple current Imin is given by the following equation, the component will not be put into
discontinuous mode.
IL[A]
I min IIN [A]
[A] 1.78[A] 0.73[A] 1.05[A] 0ꢀ
2
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●Selection of inductor L
The value of inductor has significant influence on the input ripple current. As
shown by Equation (1), the larger the inductor and the higher the switching
frequency, the inductor ripple current ∆IL becomes increasingly lower.
ΔIL
(VOUT VIN ) VIN
L VOUT fSW
ΔIL
ꢀ[A]ꢀꢀꢀꢀ・・・・・ꢀꢀ(1)
V
Expressing efficiency as shown by Equation (2), peak input current is given as
Equation (3).
IN
VOUT IOUT
VIN IIN
ꢀꢀꢀꢀꢀ・・・・・ꢀꢀ(2)
IL
L
VOUT IOUT
VIN
ΔIL
ΔIL
ILMAX IIN
ꢀꢀ ꢀꢀ ꢀ・・・・・ꢀ(ꢀ3)
2
2
VOUT
Here,
L：Inductor value[H]
VIN：input voltage[V]
IIN：input current[A]
V
OUT：DC/DC output voltage[V]
I
OUT：output total current[A]
SW：Oscillation frequency[Hz]
F
Basically, make setting of ∆IL to approximately 30% to 50% of the output load
R
current.
CS
COUT
※
If a current in excess of the rated current of the inductor applies to the coil, the inductor will cause magnetic
saturation, resulting in efficiency degradation.
Select an inductor with an adequate margin so that peak current will not exceed the rated current of the inductor.
※
To reduce power dissipation from and increase efficiency of inductor, select an inductor with low resistance
component (DCR or ACR).
●Selection of output capacitor COUT
V
IN
Select a capacitor on the output side taking into account the stability region
of output voltage and equivalent series resistance necessary to smooth
ripple voltage. Note that higher output ripple voltage may result in a drop in
LED pin voltage, making it impossible to supply set LED current.
The output ripple voltage ∆VOUT is given by Equation (4).
IL
L
IOUT
1
1
VOUT
ΔVOUT ILMAX RESR
[ꢀV]ꢀ・・・・・ꢀꢀ(4)
COUT
fSW
Here, RESR Equivalent series resistance of COUT
.
R
ESR
R
CS
COUT
※
※
Select capacitor ratings with an adequate margin for output voltage.
To use an electrolytic capacitor, an adequate margin should be provided for permissible current. Particularly to
apply PWM light modulation to LED, note that a current higher than the set LED current transiently flows.
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●Selection of switching MOSFET transistors
There will be no problem for switching MOSFET transistors having absolute maximum rating higher than rated current
of the inductor L and VF higher than “COUT breakdown voltage Rectifier diode”. However, to achieve high-speed
switching, select transistors with small gate capacity (injected charge amount).
Note: Rated current larger than overcurrent protection setting current is recommended.
Note: Selecting transistors with low on resistance can obtain high efficiency.
●Selection of rectifier diodes
Select Schottky barrier diodes having current capability higher than the rated current of the inductor L and inverse
breakdown voltage higher that COUT breakdown voltage, particularly having low forward voltage VF.
●Selection of Load switch MOSFET and soft start function
In usual DC/DC converter, because there is no switching to a path leading from VIN to VOUT resulting in output voltage
is also occur even if IC is in OFF state.Please insert PMOSFET between VIN and inductor if you want voltage to 0V
until the IC starts to operate.In addition, FAIL pin can be used for driving load switch after confirmed the logic theory,
and the breakdown voltage of drain-source needed to be selected larger than VIN.
Furthermore, if you would like to make soft start function to load switch, please insert a condenser between Gate
and Source.
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●Phase Compensation Setting Procedure
DC/DC converter application for current mode control includes one each of pole fp (phase delay) by CR filer consisting
of output capacitor and output resistor (i.e., LED current) and zero (phase lead) fZ by the output capacitor and capacitor
ESR.
Furthermore, the step-up DC/DC converter includes RHP zero “fZRHP” as the second zero. Since the RHP zero has
phase delay (90) characteristics like the pole, the crossover frequency fc should be set to not more than RHP zero.
VIN
VOUT
L
ILED
VOUT
-
+
FB
gm
RESR
COUT
RFB1
CFB2
RCS
CFB1
i.
Find Pole fp and RHP zero fZRHP of DC/DC converter.
VOUT (1 D)2
2 L ILED
ILED
fp
ꢀ[Hz] ꢀ
fZRHP
[ꢀHz]ꢀꢀ
2 VOUT COUT
VOUT VIN
ILEDꢀ＝LED Total current[A],
Here,
D
ꢀ
VOUT
ii.
Find phase compensation to be inserted to error amplifier.(set fc is 1/5 to fZRHP)
1
fRHZP RCS ILED
CFB1
[ꢀF]ꢀꢀ
RFB1
[ꢀ] ꢀ
2 RFB1 f p
5 f p gmVOUT (1 D)
gm 4.0104[S]
Here,
iii.
Find zero used to compensate ESR (RESR) of COUT (electrolytic capacitor).
RESR COUT
CFB2
[ꢀF]ꢀꢀ
RFB1
Even if a ceramic capacitor (RESR of the order of milliohms) for COUT, it is recommended to insert CFB2 for
stable operation.
To improve transient response, it is necessary to increase RFB1 and reduce CFB1. However, this improvement reduces
a phase margin. To avoid this problem, conduct thorough verification, including variations in external components, on
practical systems.
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●Timing Chart
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●List of Protect Function (typ condition)
Detect Condition
Protection
Name
Detection
Pin
Release
Condition
Protect type
Detection Pin
PWM
SS
Condition
BSx
CLx
BSx < 0.1V
H
SS > 4V
BSx > 0.1V
CLx > 0.1V
Latch
Latch
LED OPEN
CLx < 0.1V
BSx > 9V
H
H
-
SS > 4V
SS > 4V
-
LED SHORT
BSx
BSx < 9V
Latch
UVLO
UVLO < 2.79V
UVLO > 3V
Auto-restart
UVLO
OVP
REG50
VCC
REG50 < 4.2V
VCC < 7.2V
-
-
-
-
REG50 > 4.5V
VCC > 7.5V
Auto-restart
Auto-Restart
Latch
-
OVP
OVP > 2.25V
SS > 4V
OVP < 2.25V
OVP
Feedback
OVP
OVP
OVP > 2.5V
OVP < 0.2V
H
-
-
-
OVP < 2.5V
OVP > 0.2V
Pulse-by-pulse
Latch
(Pulse-by-pulse and
gate is OFF)
N output stops
(200ns Mask from
Gate ON)
SCP
OCP
CS
CS > 0.4V
-
-
CS < 0.4V
To release the latch function, STB should be set to “L” once, and then to “H”.
(CP does not charged under Soft start duration.)
*When abnormality is detected under PWM=H, CP will continue to charge even if PWM=L.
To release the latch function, STB should be set from “L” to “H”.(CP does not charged under Soft start duration.)
Operation after protect function detects error
Protect Function
DC/DC
LED Driver
Soft Start
FAIL Pin
Instantaneously
stops
Instantaneously
discharged
Instantaneously stops
STB
LED Open
LED short
UVLO
OPEN
Discharge after
CP discharged
Stops operating
after CP charged
Stops operating
charged
after CP
GND after CP charged
GND after CP charged
GND
Discharge after
CP discharged
Stops operating
after CP charged
Stops operating
charged
after CP
Instantaneously
stops
Instantaneously
discharged
Instantaneously stops
Stops operating after CP
Discharge after
CP discharged
Stops operating
after CP charged
OVP
GND after CP charged
GND after CP charged
OPEN
charged
Discharge after
CP discharged
Stops operating
charged
after CP
SCP
N output stops
Normal
operation
N pin limits duty
cycle
OCP
Normal operation
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●Operational Notes
1) We pay utmost attention to the quality control of this product. However, if it exceeds the absolute maximum ratings
including applied voltage and operating temperature range, it may lead to its deterioration or breakdown. Further, this
makes it impossible to assume a breakdown state such as short or open circuit mode. If any special mode to exceed the
absolute maximum ratings is assumed, consider adding physical safety measures such as fuses.
2) Making a reverse connection of the power supply connector can cause the IC to break down. To protect the IC form
breakdown due to reverse connection, take preventive measures such as inserting a diode between the external power
supply and the power supply pin of the IC.
3) Since current regenerated by back electromotive force flows back, take preventive measures such as inserting a capacitor
between the power supply and the ground as a path of the regenerative current and fully ensure that capacitance presents
no problems with characteristics such as lack of capacitance of electrolytic capacitors causes at low temperatures, and
then determine the power supply line. Provide thermal design having an adequate margin in consideration of power
dissipation (Pd) in the practical operating conditions.
4) The potential of the GND pin should be maintained at the minimum level in any operating state.
5) Provide thermal design having an adequate margin in consideration of power dissipation (Pd) in the practical operating
conditions.
6) To mount the IC on a printed circuit board, pay utmost attention to the direction and displacement of the IC. Furthermore,
the IC may get damaged if it is mounted in an erroneous manner or if a short circuit is established due to foreign matters
entered between output pins or between output pin and power supply GND pin.
7) Note that using this IC in strong magnetic field may cause it to malfunction.
8) This IC has a built-in thermal-protection circuit (TSD circuit), which is designed to be activated if the IC junction
temperature reached 150C to 200C and deactivated with hysteresis of 10C or more. The thermal-protection circuit (TSD
circuit) is a circuit absolutely intended to protect the IC from thermal runaway, not intended to protect or guarantee the IC.
Consequently, do not use the IC based on the activation of this TSD circuit for subsequent continuous use and operation of
the IC.
9) When testing the IC on a set board with a capacitor connected to the pin, the IC can be subjected to stress. In this case,
be sure to discharge the capacitor for each process. In addition, to connect the IC to a jig up to the testing process, be sure
to turn OFF the power supply prior to connection, and disconnect the jig only after turning OFF the power supply.
10) This monolithic IC contains P Isolation and P substrate layers between adjacent elements in order to keep them isolated.
P-N junctions are formed at the intersections of these P layers and the N layers of other elements, thus making up different
types of parasitic elements.
For example, if a resistor and a transistor is connected with pins respectively as shown in Fig.
When GND(Pin A) for the resistor, or when GND(Pin B) for the transistor (NPN), P-N junctions operate as a parasitic
diode.
When GND(Pin B) for the transistor (NPN), the parasitic NPN transistor operates by the N layer of other element
adjacent to the parasitic diode aforementioned.
Due to the structure of the IC, parasitic elements are inevitably formed depending on the relationships of potential. The
operation of parasitic diodes can result in interferences in circuit operation, leading to malfunctions and eventually
breakdown of the IC. Consequently, pay utmost attention not to use the IC for any applications by which the parasitic
elements are operated, such as applying a voltage lower than that of GND (P substrate) to the input pin.
Transistor (NPN)
B
Resistor
(Pin A)
E
C
(Pin B)
GND
N
N
P
P
P
P
N
N
N
N
N
P substrate
P substrate
GND
Parasitic element
GND
Parasitic element
(Pin B)
C
E
(Pin A)
B
Parasitic element
ＧＮＤ
Adjacent other elements
GND
Parasitic
Figure 13. 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.
www.rohm.com
TSZ02201-0F1F0C100020-1-2
25.Sep.2015 Rev.002
© 2012 ROHM Co., Ltd. All rights reserved.
25/26
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Daattaasshheeeett
BD9479FV
●Ordering Information
B D 9 4 7 9 F V
-
XX
Part Number
Package
FV:SSOP
Packaging and forming specification
XX: Please confirm the formal name
to our sales.
●Physical Dimension Tape and Reel Information
SSOP-B40
<Tape and Reel information>
13.6 0.2
Tape
Embossed carrier tape
2000pcs
(MAX 13.95 include BURR)
Quantity
40
21
E2
Direction
of feed
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
(
)
1
20
0.15 0.1
0.1
S
0.65
0.22 0.1
Direction of feed
1pin
M
0.08
Reel
Order quantity needs to be multiple of the minimum quantity.
(Unit : mm)
∗
www.rohm.com
TSZ02201-0F1F0C100020-1-2
25.Sep.2015 Rev.002
© 2012 ROHM Co., Ltd. All rights reserved.
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Daattaasshheeeett
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
intend to use our Products in devices requiring extremely high reliability (such as medical equipment (Note 1), transport
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
CLASSⅣ
CLASSⅡb
CLASSⅢ
CLASSⅢ
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 on a surface-mount products, the flow soldering method must
be used on a through hole mount products. If the flow soldering method is preferred on a surface-mount products,
please consult with the ROHM representative in advance.
For details, please refer to ROHM Mounting specification
Notice-PGA-E
Rev.001
© 2015 ROHM Co., Ltd. All rights reserved.
Daattaasshheeeett
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 concerned goods might be fallen under listed items of export control prescribed by Foreign exchange and Foreign
trade act, please consult with ROHM 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.
2. ROHM shall not have any obligations where the claims, actions or demands arising from the combination of the
Products with other articles such as components, circuits, systems or external equipment (including software).
3. 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 Products or the information contained in this document. Provided, however, that ROHM
will not assert its intellectual property rights or other rights against you or your customers to the extent necessary to
manufacture or sell products containing the Products, subject to the terms and conditions herein.
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-PGA-E
Rev.001
© 2015 ROHM Co., Ltd. All rights reserved.
Daattaasshheeeett
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 not be in an y way responsible or liable for failure, malfunction or accident 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 any damages, expenses or losses incurred by you or third parties resulting from inaccuracy or errors of or
concerning such information.
Notice – WE
Rev.001
© 2015 ROHM Co., Ltd. All rights reserved.
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