BD9421F-GE2 [ROHM]
LED Driver, 72-Segment, PDSO24, 15 X 7.80 MM, 2.01 MM HEIGHT, 1.27 MM PITCH, ROHS COMPLIANT, SOP-24;型号: | BD9421F-GE2 |
厂家: | ROHM |
描述: | LED Driver, 72-Segment, PDSO24, 15 X 7.80 MM, 2.01 MM HEIGHT, 1.27 MM PITCH, ROHS COMPLIANT, SOP-24 驱动 光电二极管 接口集成电路 |
文件: | 总30页 (文件大小:1176K) |
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)
BD9421F
General Description
Key Specifications
BD9421F is high efficiency driver for white LED. This is
designed for large sized LCD. BD9421F is built-in
DCDC converters that supply appropriate voltage for
light source.
VCC Supply Voltage Range:
9.0V to 35.0V
DCDC Oscillation Frequency:150kHz(RT=100kΩ)
Operation Circuit Current:
Operating Temperature Range:
5mA(Typ)
-40°C to +85°C
BD9421F is also built-in protection function for
abnormal state such as OVP: over voltage protection,
OCP: over current limit protection of DCDC, SCP: short
circuit protection, open detection of LED string.
Thus this is used for conditions of large output voltage
and load conditions.
Applications
LED driver for TV, Monitor and LCD Back Light
Package
W(Typ) x D(Typ) x H(Max)
15.00mm x 7.80mm x 2.01mm
Pin Pitch 1.27mm
SOP24
Features
6ch LED constant current driver(External PNP Tr
Type)
Maximum LED setting current 500mA(VREF Pin
setting)
±2% LED current accuracy(VREF=0.9V setting)
Built-in DC/DC converter
Analog Dimming(Linear) function
LED protection function(OPEN/SHORT
protection)[PWM-independent Type]
Individual detection and individual LED OFF for both
OPEN and SHORT circuit
VOUT Over Voltage Protection(OVP) and reduced
voltage protection(SCP) circuit
Built-in under voltage lockout function(UVLO) and
over voltage protection(OVP)
Figure 1. SOP24
Built-in VOUT discharge circuit while shutdown
Typical Application Circuit
Figu2. Typical Application Circuit
〇Product structure : Silicon monolithic integrated circuit 〇This product has no designed protection against radioactive rays
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BD9421F
Absolute Maximum Ratings(Ta = 25°C)
Parameter
Symbol
Rating
Unit
Supply Voltage
VCC
STB,OVP
BS1-6
-0.3 to +36
-0.3 to +36
-0.3 to +60
-0.3 to +7
-0.3 to +14
-0.3 to +20
0.68 (Note 1)
-40 to +85
-55 to +150
150
V
V
STB,OVP Voltage
BS1-6 Voltage
V
CS,CL1-6,FB,RT Voltage
REG75,N Voltage
CS,CL1-6,FB,RT
REG75,N
PWM,VREF
Pd
V
V
PWM,VREF Voltage
V
Power Dissipation for SOP24
Operating Temperature Range
Storage Temperature Range
Maximum Junction Temperature
W
°C
°C
°C
Topr
Tstg
Tjmax
(Note 1) Derating in done 5.5mW/°C for operating above Ta≧25°C (Mount on 1-layer 70.0mm x 70.0mm x 1.6mm board)
Caution: Operating the IC over the absolute maximum ratings may damage the IC. The damage can either be a short circuit between pins or an open circuit
between pins and the internal circuitry. Therefore, it is important to consider circuit protection measures, such as adding a fuse, in case the IC is operated over
the absolute maximum ratings.
Recommended Operating Conditions(Ta= -40°C to +85°C)
Parameter
Supply Voltage
Symbol
Min
Typ
Max
Unit
VCC
FSW
VREF
9
24
-
35
800
3.0
V
kHz
V
DC/DC Oscillation Frequency
100
0.6
Analog Dimming Setting Input Range
0.9
External Component Recommended Range
Parameter
Symbol
Specification
Unit
VCC pin connecting capacity
CVCC
C_REG
RRT
1 to 100
1.0 to 10
uF
uF
kΩ
REG75 pin connecting capacity
RT pin connection resistance range
18.75 to 150
The operating conditions listed above are constants for the IC alone. To make constant setting with practical set devices, utmost attention should be paid.
Pin Configuration
Marking Diagram and Physical Dimension
(TOP VIEW)
BD9421F
1PIN MARK
LOT No.
SOP24
Figure 3. Pin Configuration
Figure 4. Physical Dimension
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BD9421F
Electrical Characteristics(Unless otherwise specified VCC=24V Ta=25°C)
Limit
Parameter
[Whole Device]
Symbol
Unit
Condition
Min.
Typ.
Max.
-
-
Operation Current
ICC
IST
5
10
80
mA VSTB=3V
uA VSTB=0V
Standby Current
40
[UVLO Block]
Operation Voltage (VCC)
VUVLO_VCC
VUHYS_VCC
6.5
7.5
8.5
V
VCC=SWEEP UP
Hysteresis Voltage (VCC)
150
300
600
mV VCC=SWEEP DOWN
[DC/DC Block]
Error amp Base Voltage
Oscillation Frequency
VEAMP
FCT
0.55
142.5
90
0.60
150.0
95
0.65
157.5
99
V
BSx pin, VREF=0.9V
kHz RT=100kΩ
N Pin MAX DUTY Output
N Pin Source ON Resistance
N Pin Sink ON Resistance
RT Pin Voltage
NMAX_DUTY
RNSO
%
Ω
Ω
V
RT=100kΩ
2.5
2
5
10
RNSI
4
8
VRT
1.60
-0.3
-
2.00
-
2.40
VRTx90%
4.0
RT=100kΩ
RT Short Protection Range
RT Pin Low Resistance
RT_DET
RRT_L
V
RT=SWEEP DOWN
2.0
kΩ VSTB=0V
VBSx=0V, VREF=0.9V,
uA VFB=1.0V
VBSx=2.0V, VREF=0.9V,
uA VFB=1.0V
FB Pin Source Current
IFBSO
-115
-100
-85
FB Pin Sink Current
IFBSI
VCS
ICS
85
0.35
15
100
0.40
30
115
0.45
60
Over Current Detect Voltage
V
CS=SWEEP UP
CS Source Current
uA VCS=0V
[DC/DC Protection Block]
OVP High Detect Voltage
VOVPH
2.88
3.00
3.12
V
VOVP SWEEP UP
OVP Hysteresis Voltage
VOVPH_HYS
VSCP
150
200
250
V
V
VOVP SWEEP DOWN
VOVP SWEEP DOWN
Short Protection Detect Voltage
0.05
0.10
0.15
OVP Pin Leakage Current
OVP_LK
-2
0
2
uA VOVP=4V
[LED PNP Driver Block]
CL Pin Current Setting Voltage
CL Pin Current Setting Voltage
(Analog MAX)
CL Pin Current Setting Voltage
(Analog MIN)
VCL
294.0
-3%
300.0
1.0
306.0
+3%
+3%
mV VREF=0.9V
VCLMAX
VCLMIN
V
VREF max=3.0V
-3%
200.0
mV VREF min=0.6V
PNP Driver Output Sink
Resistance
RBS
55
-2
80
0
120
2
Ω
PWM=High, VCL=Low
VREF Pin Leakage Current
VREF_LK
uA VREF=1V
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BD9421F
Electrical Characteristics(Unless otherwise specified VCC=24V Ta=25°C)
Limit
Parameter
Symbol
Unit
Condition
Min.
Typ.
Max.
[LED Protection Block]
LED OPEN Detect Voltage
LED SHORT Detect Voltage
VOPEN
VLSP
0.05
8.5
0.10
9.0
0.15
9.5
V
V
V
BSx=SWEEP DOWN
BSx=SWEEP UP
CL Pin Low Detect Voltage
VCLLVP
0.05
0.10
0.15
[REG75 Block]
REG75 Output Voltage
REG75
7.425
10
7.50
7.575
-
V
Io=0mA
REG75 MAX Output Current
| IREG75 |
-
mA
REG75_UVLO Detect Voltage
REG75_UVLO Hysteresis
REG75_TH
3.6
4.0
4.4
V
REG75=SWEEP DOWN
STB=ON->OFF,
REG75=SWEEP UP
STB=ON->OFF,
REG75=7.5V
REG75_HYS
250
500
750
mV
REG75 Discharge Resistance
REG75_DIS
0.65
1.00
1.35
MΩ
[STB Block]
STB Pin High Voltage
STB Pin Low Voltage
STBH
STBL
RSTB
2.0
-0.3
600
-
-
VCC
0.8
V
V
STB=SWEEP UP
STB=SWEEP DOWN
STB Pin Pull Down Resistance
1000
1400
kΩ STB=3.0V
[PWM Input Block]
PWM Pin High Detect Voltage
PWM Pin Low Detect Voltage
PWM Pin Pull Down Resistance
PWM_H
PWM_L
RPWM
1.5
-0.3
300
-
-
18
0.8
700
V
V
PWM=SWEEP UP
PWM=SWEEP DOWN
500
kΩ PWM=3.0V
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BD9421F
Pin Descriptions
Pin No.
Pin Name
REG75
N
Function
7.5V regulator output for N output pin
DC/DC switching output pin
1
2
3
PGND
CS
Power GND
4
DCDC external NMOS current monitor pin
DCDC phase-compensation pin
LED voltage setting pin
5
FB
6
VREF
BS1
BS2
BS3
BS4
BS5
BS6
CL6
7
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 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
Dimming signal input pin
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
CL5
CL4
CL3
CL2
CL1
PWM
OVP
RT
Overvoltage protection detection pin
DCDC frequency setting resistor connection pin
Analog GND
AGND
STB
VCC
Enable pin
Power supply pin
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BD9421F
Block Diagram
Vo
+
VIN
CIN
OVP
REF4V
OVP
UVLO
(VCC)
VCC
STB
REG75
Protection
TSD
OCP
VREG
OPEN
SHORT
Detect
CP counter
・・・
REG75
OSC CLK
Control Logic
N
RT
OSC
PGND
CS
ERROR
PGND
Soft Start
OSC CLK
SS counter
-
AGND
FB
-
-
-
ERR
AMP
RFB
CFB
VREF*2/3
1/10
+
+
+
Comp
+
+
SHORT_DET
REF4V
1/10
-
0.9V
0.9V
-
-
OPEN_DET
-
-
Comp
REG75
+
0.1V
Analog
Dimming
VREF
1/3
PWM
Figure 5. Blockdiagram
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BD9421F
Pin ESD Type
REG75 / N / PGND / CS
PWM
FB
STB
VREF
BS(1-6) / CL(1-6)
OVP
RT
OVP
Figure 6. Pin ESD Type
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BD9421F
Description of pin function
P in 1: REG75
The REG pin is used in the DC/DC converter driver block to output 7.5V power. The maximum operating current is 10mA.
Using the REG pin at a current higher than 10mA 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 7.5V. 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.
Pin 5: FB
Current mode control DC/DC converter error amplifier output pin. By monitoring voltage of BS(1~6)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 6: 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 high 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 7-12: BS1-BS6
LED DRIVER output pin. Please connect to Base Terminal of external PNP Tr.
Pin 13-18: CL6 – CL1
LED current detect pin. By monitoring voltage of CLx pin to detect LED current.
Please connect resistor to collector pin of external PNP Tr. CLx pin of no use channel set CLx>3.3V.
Pin 19: PWM
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
PWM Voltage
LED ON state
LED OFF state
PWM= 1.5V~18.0V
PWM= -0.3V~0.8V
Pin 20: 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 3.0V or higher, CP counting start.
When OVP pin voltage<0.1V (typ.) or lower, short circuit protection (SCP) function is activated, and output of Gate driver
will become low immediately.
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BD9421F
Pin 21: 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=100kΩ,Frequency=150kHz(typ.).
For calculation example, please refer to section in “P15 – DC/DC drive frequency setting”.
When it reaches under VRT×0.90V(typ), DCDC operation will be stopped in order to prevent from high speed oscillation
when the RT resistance is shorted to GND. And when RT pin returns to normal state, DCDC also returns to operation.
Pin 22: AGND
GND pin for analog system inside IC.
Pin 23: 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 24: 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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BD9421F
Typical Performance Curves
10
9
8
7
6
5
4
3
2
1
0
10
9
8
7
6
5
4
3
2
1
0
9
13
17
21
VCC[V]
25
29
33
9
13
17
21
VCC[V]
25
29
33
Figure 7. Operating Current[mA] vs VCC Input Voltage[V]
Figure 8. REG75 Output Voltage[V] vs VCC Input Voltage[V]
2.0
10.00
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
1.00
0.10
0.01
15 35 55 75 95 115 135 155 175 195
0.6
1.1
1.6
2.1
2.6
RRT[k ]
VREF[V]
Ω
Figure 10. N Frequency[MHz] vs RT Resistance[kΩ]
Figure 9. CLx Voltage[V] vs VREF Input Voltage[V]
1.0
160
120
80
0.8
0.6
0.4
0.2
0.0
40
0
-40
-80
-120
-160
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
VBSx[V]
-40
-20
0
20
TEMP[
40
]
60
80
℃
Figure 12. FB Current[uA] vs BSx Voltage[V]
Figure 11. CLx Voltage[V] vs Temperature[℃]
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BD9421F
●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 REG75, it
is possible to use resistive divider by setting 88kohm and 12kohm.
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]
I
LED [A]3
For current setting, set at each channel. For this reason, in 1ch~3ch and 4ch~6ch, 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 ideal equations 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]
【Setting Example】
If DCDC frequency is set to be 200kHz, RRT as below:
15000
15000
RRT
75 [k] ꢀ
fsw[kHz] 200[kHz]
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BD9421F
●Maximum DCDC output Voltage
In this IC, 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 been varying with 1.6V while Analog dimming is performed (2/3 of 3.0V -
0.6V).
●Soft Start Time setting
This IC have a built in soft start time setting, there is no need to change from the outside. Timer time can be set by
counting the clock frequency with RT pin. Starts counting when shutdown function terminal STB etc is released, and start
time are considered in the count (in soft-start). Therefore, LED OPEN protection ・SHORT protection are not detected
during this time.
The soft start time is set inside the IC, as the following equation.
(Please note that soft-start time set here is the mask of the running time and not the time until the output stabilizes of the
DCDC. Time to stabilize the output or load is greater than the boost DCDC dependent.)
Soft-start time "TSS", RT pin connection resistor "RRT" :
RRT []
TSS [sec] 12480
1.51010
Start-up sequence
The following describes the start-up sequence of this IC.
①
Internal SS
STB
SLOPE
FB
OSC
PWM
N
②
VOUT
③
ILED
④
LED_OK
⑥
⑤
○Description of start-up sequence
①Set STB from Low to High
②System will be activated while PWM=H. SS counting start.
At this time, a circuit in which internal SS voltage for slow start becomes equal to FB pin voltage operates to
equalize the FB pin and internal SS voltages regardless of whether the PWM pin is set to Low or High level.
③Since the FB pin and internal SS 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.
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BD9421F
VOUT
●OVP/SCP setting procedure (OVP Pin)
The OVP pin is an input pin for overvoltage protection and short
circuit protection of DC/DC output voltage. The OVP pin is a high
impedance type and no pull-down resistor inside, resulting in
unstable potential in the open circuit state. To avoid this problem, be
sure to make input voltage setting with the use of a resistive divider.
R1
OVP
+
-
3.0V/2.8V
R2
○OVP detect 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.
0.1V
+
○OP reetting equt
When R1 and 2 setting is dtened by e equation shown above, OVP release voltage VOVPCAN will be given by the
following equation :
○SCP detect stig
The SCP setting「VSCPDET」 vis caculated as below when R1,R2 is decided above:
(R1[k] R2[k])
VSCP 0.1V
[V]
DET
R2[k]
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BD9421F
●Timer latch function
This IC has a built-in timer latch counter to make setting of timer latch time by counting a clock frequency set with the RT
pin.
○Timer latch time
The timer latch counter begins counting from the timing when any abnormal state is detected. The timer will be latched
after a lapse of a period of time given by the following equation.
If the abnormal state continues even when PWM is set to Low level, the counter will not reset counting.
Here LATCHTIME= A period of time, which the timer is
latched
RRT=RT pin connecting resistance
Protection time which dced above is applied LEOPEN protection, LED SHORT protection, SCP protection.
OVP protection as below:
Clock oscillatioof timlh uses DCDC ccier latch time depend on unevenness of DCDC oscillation. In
150kHz, timer latch time is % unevenness.
【Setting Example】
In LED_OPEN protection, LED_SHORT protection, SCP
protection,
When RT resistance=100kohm, the timer latch time is
And OVP protection is
Figure 13-1. Timing chart of LSP time latch
To prevent the miss detection there is 4 count interval of mask before starting the timer count at LED OPEN, SHORT and
GND SHORT protection.
If PWM=H time is
PWM=H time < 4count・・・Not detect protection because it is in interval time
PWM=H time > 4count・・・Detect protection because it is out of interval time
Please verify enough to operate narrow PWM.
Figure 13-2. Timing chart of Timer count
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BD9421F
●Selection of DC/DC Components
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 if the 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 .
○Peak coil current Ipeak calculation
VOUT
Ripple voltage generated at the CS pin is determined by conditions
for DC/DC application components first, Assuming the conditions as
below:
L
VIN
IL
「output voltage=VOUT[V] 」
「LED total current=IOUT[A] 」
「DCDC input voltage=VIN[V] 」
「DCDC efficiency=η[%] 」
fsw
N
CS
And then mean input current IIN required for the whole system is given
by the following equation.
Rcs
VOUT [V] IOUT [A]
VIN [V][%]
PGND
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.
I peak IOCP
MAX current tolerance
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.
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BD9421F
【Setting example】
Output=VOUT[V]=40V
LED 1ch current=120mA, total LED current IOUT[A]=120mA×6ch=0.72A
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:
DCDC switching frequncyw[Hz]=k
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.
When RCS resistance is set to 0.1ohm, he VCS eak vtage wiiven by e followineqtion:
Consequently, the result ms the condition.
Furthermore, IOCP current at which OCP is detected is given by the foloing 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.
Max. Current tolerance for component
I peak IOCP
Particularly, To select DC/DC components, give consideration to vaiatons as elaididual component
variations, and then conduct thorough verification on practical syse..
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] 1.33[A] 0.73[A] 0.60[A] 0
2
※For the selection of DC/DC compoents, please also consider the inaccuracy of eah componentts.
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BD9421F
○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
IN
Expressing efficiency as shown by Equation (2), peak input current is given as
Equation (3).
IL
L
VOUT IOUT
VIN IIN
ꢀꢀꢀꢀꢀ・・・・・ꢀꢀ(2)
VOUT
VOUT IOUT
VIN
ΔIL
ΔIL
ILMAX IIN
ꢀꢀ ꢀꢀ ꢀ・・・・・ꢀ(ꢀ3)
2
2
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]
R
FSW:Oscillation frequency[Hz]
CS
COUT
Basically, make setting of ∆IL to approximately 30% to 50% of the output load
current.
※
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
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).
V
IN
IL
IOUT
1
1
L
ΔVOUT ILMAX RESR
[ꢀV]ꢀ・・・・・ꢀꢀ(4)
COUT
fSW
VOUT
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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BD9421F
○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 occurring 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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BD9421F
●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
ILEDꢀ=LED Total current[A],
Here,
VOUT VIN
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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BD9421F
●The setting of REG75 capacity and shutdown procedure
VOUT discharge function is built-in this IC when IC is shutdowned, the below decribes the operation sequence.
Figure 14.Timing chart of shutdown
○Explanation of shutdown sequence
①Set STB pin to “OFF” will stops DC/DC converter and REG75, but LED driver will remain operation.
②Discharge the REG75 pin voltage from 7.5V to 4.0V with 1MΩ.
③The VOUT voltage will be discharged with ILED current and the discharged VOUT voltage is no flow ILED current.
④When REG75 pin voltage will reach 4.0V (Typ.) or less to shut down all systems
○REG75 capacitance setting procedure
The shutdown time “TOFF” can be calaulated by the following equation.
REG75 [V]
7.5[V]
4.0[V]
3
t0
T [sec] C [F] R [] In
C [F]1[M] In
628.6 10 C [sec]
OFF
REG
REG
REG
REG
REG75 [V]
UVLO
The longest VOUT discharge time will be obtained when the PWM duty cycle is set to the minimum VOUT.
Make REG capacitance setting with an adequate margin so that systems will be shut off after VOUT voltage is fully
discharged.
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BD9421F
●Timing Chart
7.5V
VCC
STB
2.0V
0.8V
PWM
4.5V
REG75
RT
2.0V
4.0V
Internal SS
FB
VOUT
Protect Function
disable
disable
disable
disable
LED OPEN
LED SHORT
OVP
disable
disable
disable
disable
*Under SS term, Not charge CP
disable
disable
SCP
OCP
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BD9421F
●List of Protection Functions
○List of protection detecting condition
Detection
Protection
Detection condition
PWM
Release
condition
Protection
type
Timer
Detection pin
condition
names
pin
SS
H(Pulse
over 4CLK)
H(Pulse
over 4CLK)
H(Pulse
over 4CLK)
H(Pulse
over 4CLK)
BSx
BSx < 0.1V
CLx < 0.1V
BSx > 9V
SS>4.0V
BSx > 0.1V
CLx > 0.1V
BSx < 9V
Latch(Only
detected ch)
LED OPEN
215count
215count
CLx
SS>4.0V
Latch(Only
detected ch)
LED SHORT
BSx
SS>4.0V
LED GND
SHORT
RT GND
SHORT
215+27coun
t
BSx
BSx < 0.1V
SS>4.0V
BSx > 0.1V
Latch
Under RT
x90%
Canceled
RT=GND State
Immediatel
y detect
Immediatel
y detect
Immediatel
y detect
RT
-
-
-
-
-
-
Auto-restart
Auto-restart
Auto-restart
VCC UVLO
VCC
REG75
VCC < 7.2V
VCC>7.5V
REG75
UVLO
REG75 < 4.0V
REG75>4.5V
OVP
SCP
OVP
OVP
OVP>3.0V
-
-
-
-
OVP<2.8V
218count
215count
Latch
Latch
OVP < 0.1V
OVP > 0.1V
Immediatel
y detect
OCP
CS
CS>0.4V
-
-
CS<0.4V
Pulse by Pulse
・To clear the latch type, STB should be set to “L” once, and then to “H”.
・The count of Timer means “1count=1duty of switching frequency.”
○List of protection detecting operation
Operation when the hysteresis type protection is detected
Protection
Functions
DC/DC
LED Driver
Soft start
RT pin
Stops operating
Only detected LED stops
Low after all ch
Latch
Low after all ch
Latch
LED OPEN
after CP counting operating after CP counting
Stops operating Only detected LED stops
after CP counting operating after CP counting
Low after all ch
Latch
Low after all ch
Latch
LED SHORT
LED GND
SHORT
RT GND
SHORT
Stops operating
after CP counting
Instantaneously
stops operating
Instantaneously
stops operating
Instantaneously
stops operating
Instantaneously
stops operating
Stops operating after CP
counting
Discharge after
CP counting
Low after CP
counting
Instantaneously stops
operating
Not discharged
Discharge
-
Instantaneously stops
operating
VCC UVLO
REG75 UVLO
OVP
Normal operation
Normal operation
Instantaneously stops
operating
Discharge
Stops operating after CP
counting
Discharge after
CP counting
Low after CP
counting
Stops operating after CP
counting
Discharge after
CP counting
Low after CP
counting
SCP
OCP
N output stops
Limits duty cycle
Normal operation
Not discharged
Normal operation
<Example>
Case FOSC=150kHz
○LED OPEN,LED SHORT,SCP
32768count→Latch after 218.5msec
○LED GND SHORT
32896count→Latch after 219.3msec
○OVP
262144count→Latch after 1.748sec
○Soft Start time
12480count→83.2msec
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BD9421F
○Timing of Error detection
This IC is individual Latch OFF. Therefore, Error detection is every channel.
The detection timing of LED OPEN, SHORT and GND SHORT Protection is different with PWM Duty or Timing of Error state as
follows:
(A).Other channels will be in Error states within 4counts of internal CLK. [When PWM=100%]
※Error detection is same timing.
(B).Other channels will be in Error states after 4counts of internal CLK. [When PWM=100%]
PWM
H
0.3V
CL1_Voltage
CL2_Voltage
0V
0.3V
0V
Oscllator
(Internal IC)
4CLK
CH1_Error_Detect
(Internal IC)
Error detect
CH2_Error_Detect
(Internal IC)
Error no detect
L
※Error detection is only first Error state channel.
(C).Other channels will be in Error states after 4counts of internal CLK. [When except PWM=100%]
※First Error state channel is Latch OFF. Then, the detection of the following channel can detect whenever the new edge
of PWM comes. Finally, all Error state channels are Latch off.
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BD9421F
Operational Notes
1.
Reverse Connection of Power Supply
Connecting the power supply in reverse polarity can damage the IC. Take precautions against reverse polarity when
connecting the power supply, such as mounting an external diode between the power supply and the IC’s power supply
terminals.
2. Power Supply Lines
Design the PCB layout pattern to provide low impedance supply lines. Separate the ground and supply lines of the
digital and analog blocks to prevent noise in the ground and supply lines of the digital block from affecting the analog
block. Furthermore, connect a capacitor to ground at all power supply pins. Consider the effect of temperature and
aging on the capacitance value when using electrolytic capacitors.
3.
4.
Ground Voltage
Ensure that no pins are at a voltage below that of the ground pin at any time, even during transient condition.
Ground Wiring Pattern
When using both small-signal and large-current ground traces, the two ground traces should be routed separately but
connected to a single ground at the reference point of the application board to avoid fluctuations in the small-signal
ground caused by large currents. Also ensure that the ground traces of external components do not cause variations on
the ground voltage. The ground lines must be as short and thick as possible to reduce line impedance.
5.
Thermal Consideration
Should by any chance the power dissipation rating be exceeded the rise in temperature of the chip may result in
deterioration of the properties of the chip. The absolute maximum rating of the Pd stated in this specification is when the
IC is mounted on a 70mm x 70mm x 1.6mm glass epoxy board. In case of exceeding this absolute maximum rating,
increase the board size and copper area to prevent exceeding the Pd rating.
6.
7.
Recommended Operating Conditions
These conditions represent a range within which the expected characteristics of the IC can be approximately obtained.
The electrical characteristics are guaranteed under the conditions of each parameter.
Inrush Current
When power is first supplied to the IC, it is possible that the internal logic may be unstable and inrush current may flow
instantaneously due to the internal powering sequence and delays, especially if the IC has more than one power supply.
Therefore, give special consideration to power coupling capacitance, power wiring, width of ground wiring, and routing of
connections.
8.
9.
Testing on Application Boards
When testing the IC on an application board, connecting a capacitor directly to a low-impedance output pin may subject
the IC to stress. Always discharge capacitors completely after each process or step. The IC’s power supply should
always be turned off completely before connecting or removing it from the test setup during the inspection process. To
prevent damage from static discharge, ground the IC during assembly and use similar precautions during transport and
storage.
Inter-pin Short and Mounting Errors
Ensure that the direction and position are correct when mounting the IC on the PCB. Incorrect mounting may result in
damaging the IC. Avoid nearby pins being shorted to each other especially to ground, power supply and output pin.
Inter-pin shorts could be due to many reasons such as metal particles, water droplets (in very humid environment) and
unintentional solder bridge deposited in between pins during assembly to name a few.
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BD9421F
Operational Notes – continued
10. Unused Input Terminals
Input terminals of an IC are often connected to the gate of a MOS transistor. The gate has extremely high impedance
and extremely low capacitance. If left unconnected, the electric field from the outside can easily charge it. The small
charge acquired in this way is enough to produce a significant effect on the conduction through the transistor and
cause unexpected operation of the IC. So unless otherwise specified, unused input terminals should be connected to
the power supply or ground line.
11. Regarding the Input Pin of the IC
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 intersection of the P layers with the N layers of other elements, creating a
parasitic diode or transistor. For example (refer to figure below):
When GND > Pin A and GND > Pin B, the P-N junction operates as a parasitic diode.
When GND > Pin B, the P-N junction operates as a parasitic transistor.
Parasitic diodes inevitably occur in the structure of the IC. The operation of parasitic diodes can result in mutual
interference among circuits, operational faults, or physical damage. Therefore, conditions that cause these diodes to
operate, such as applying a voltage lower than the GND voltage to an input pin (and thus to the P substrate) should
be avoided.
Figure 15. Example of monolithic IC structure
12. Ceramic Capacitor
When using a ceramic capacitor, determine the dielectric constant considering the change of capacitance with
temperature and the decrease in nominal capacitance due to DC bias and others.
13. Area of Safe Operation (ASO)
Operate the IC such that the output voltage, output current, and power dissipation are all within the Area of Safe
Operation (ASO).
14. Thermal Shutdown Circuit(TSD)
This IC has a built-in thermal shutdown circuit that prevents heat damage to the IC. Normal operation should always be
within the IC’s power dissipation rating. If however the rating is exceeded for a continued period, the junction
temperature (Tj) will rise which will activate the TSD circuit that will turn OFF all output pins. When the Tj falls below the
TSD threshold, the circuits are automatically restored to normal operation.
Note that the TSD circuit operates in a situation that exceeds the absolute maximum ratings and therefore, under no
circumstances, should the TSD circuit be used in a set design or for any purpose other than protecting the IC from heat
damage.
15. Over Current Protection Circuit (OCP)
This IC incorporates an integrated overcurrent protection circuit that is activated when the load is shorted. This
protection circuit is effective in preventing damage due to sudden and unexpected incidents. However, the IC should
not be used in applications characterized by continuous operation or transitioning of the protection circuit.
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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BD9421F
Ordering Information
B D 9 4 2 1 F
-
XX
Part Number
Package
F:SOP24
Packaging and forming specification
XX: Please confirm the formal name
to our sales.
Physical Dimension, Tape and Reel Information
SOP24
<Tape and Reel information>
15.0 0.2
Tape
Embossed carrier tape
2000pcs
(MAX 15.35 include BURR)
Quantity
24
13
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
12
0.15 0.1
1.27
0.4 0.1
0.1
Direction of feed
1pin
Reel
Order quantity needs to be multiple of the minimum quantity.
(Unit : mm)
∗
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BD9421F
Revision History
Date
Revision
001
Changes
11.Nov.2013
New Release
P14. Timing chart of Timer count add
P22. Detection condition add
P23. Timing of Error detection add
P2. External Component Recommended Range add
P8. No use channel setting add
31.Jan.2014
25.Sep.2015
002
003
P22. Protection condition change
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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
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.
相关型号:
BD9423EFV-E2
LED Driver, 24-Segment, PDSO40, 13.60 X 7.80 MM, 1 MM HEIGHT, 0.65 MM PITCH, ROHS COMPLIANT, HTSSOP-40
ROHM
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