LED Drivers for LCD Backlights
1ch Boost up Type
White LED Driver for large LCD
BD9411F
General Description
Key Specifications
BD9411F is a high efficiency driver for white LEDs and is
designed for large LCDs. BD9411F has a boost DCDC
converter that employs an array of LEDs as the light
source.
BD9411F has some protect functions against fault
conditions, such as over-voltage protection (OVP), over
current limit protection of DCDC (OCP), LED OCP
protection, and over-boost protection (FBMAX).
Therefore it is available for the fail-safe design over a
wide range output voltage.
Operating power supply voltage range: 9.0V to 35.0V
Oscillator frequency of DCDC: 150kHz (RT=100kΩ)
Operating Current:
3.3 mA(Typ)
Operating temperature range:
-40°C to +105°C
Package(s)
W(Typ) x D(Typ) x H(Max)
11.20mm x 7.80mm x 2.01mm
Pin pitch 1.27mm
SOP18
Features
DCDC converter with current mode
LED protection circuit (Over boost protection, LED
OCP protection)
Over-voltage protection (OVP) for the output voltage
VOUT
Adjustable soft start
Adjustable oscillation frequency of DCDC
Wide range of analog dimming 0.2V to 3.0V
UVLO detection for the input voltage of the power
stage
LED Dimming PWM Over Duty Protection(ODP)
Figure 1.
SOP18
Applications
TV, Computer Display, LCD Backlighting
Typical Application Circuit
VOUT
VCC
VIN
VCC
UVLO
OVP
REG90
STB
GATE
RT
CS
SS
FAIL
DIMOUT
PWM
ADIM
ISENSE
DUTYP
FB
Rs
DUTYON
GND
Figure 2. Typical Application Circuit
○Product structure：Silicon monolithic integrated circuit
.www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・14・001
○This product has not designed protection against radioactive rays
1/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
Pin Configuration(s)
1
VCC
REG 90
18
2
STB
CS
17
3
OVP
GATE
16
4
UVLO
DIMOUT
15
5
SS
GND
14
6
DUTYON
ISENSE
13
7
PWM
FB
12
8
FAIL
DUTYP
11
9
ADIM
RT
10
Figure 3. Pin Configuration
Pin Description(s)
Terminal
No.
Name
1
VCC
2
Function
Power supply pin
STB
IC ON/OFF pin
3
OVP
Over voltage protection detection pin
4
UVLO
Under voltage lock out detection pin
5
SS
6
DUTYON
Soft start setting pin
7
PWM
External PWM dimming signal input pin
8
FAIL
Error detection output pin
9
ADIM
ADIM signal input pin
10
RT
11
DUTYP
12
FB
13
ISENSE
Over Duty Protection ON/OFF pin
DC/DC switching frequency setting pin
Over Duty Protection setting pin
Error amplifier output pin
LED current detection input pin
14
GND
15
DIMOUT
Dimming signal output for NMOS
16
GATE
17
CS
18
REG90
DC/DC switching output pin
DC/DC output current detect pin,
OCP input pin
9.0V output voltage pin
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
2/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
Block Diagram(s)
VCC
VIN
VCC
UVLO
OVP
REG 90
VCC
UVLO
VREG
STB
UVLO
OVP
TSD
REG 90
UVLO
1MΩ
REG90
RT
+
-
OSC
PWM
COMP
GATE
CONTROL
LOGIC
CS
SS
LEB
Current
sense
SS
REG90
FAIL
SS - FB
clamper
DIMOUT
Fail
detect
LEDOCP
Auto Restart
Control
PWM
ERROR
amp
+
+
ISENSE
1.015V
Rs
FB
1MΩ
DUTYP
OverBoost
Over Duty
Protection
OSC
DUTYON
1MΩ
ADIM
1/3
Package:SOP18
GND
Figure 4. Block Diagram
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
3/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
Absolute Maximum Ratings (Tj=25°C)
Rating
Unit
-0.3 to +36
V
-0.3 to +7
V
REG90, DIMOUT, GATE
-0.3 to +13
V
OVP, UVLO, PWM,
ADIM, STB, FAIL,
DUTYON
-0.3 to +20
V
Topr
-40 to +105
°C
Tjmax
150
°C
Tstg
-55 to +150
°C
Parameter
Power Supply Voltage
SS, RT, ISENSE, FB, CS,
DUTYP Pin Voltage
REG90, DIMOUT, GATE
Pin Voltage
OVP, UVLO, PWM, ADIM, STB,
FAIL, DUTYON
Pin Voltage
Symbol
VCC
SS, RT, ISENSE, FB, CS,
DUTYP
Operating Temperature Range
Junction Temperature
Storage Temperature Range
Thermal Resistance
(Note 1)
Parameter
Thermal Resistance (Typ)
Symbol
1s
(Note 3)
(Note 4)
2s2p
Unit
SOP18
Junction to Ambient
Junction to Top Characterization Parameter
(Note 2)
θJA
179.3
119.9
°C/W
ΨJT
20.0
17.0
°C/W
(Note 1)Based on JESD51-2A(Still-Air)
(Note 2)The thermal characterization parameter to report the difference between junction temperature and the temperature at the top center of the outside
surface of the component package.
(Note 3)Using a PCB board based on JESD51-3.
(Note 4)Using a PCB board based on JESD51-7.
Layer Number of
Measurement Board
Single
Material
Board Size
FR-4
114.3mm x 76.2mm x 1.57mmt
Top
Copper Pattern
Thickness
Footprints and Traces
70μm
Layer Number of
Measurement Board
4 Layers
Material
Board Size
FR-4
114.3mm x 76.2mm x 1.6mmt
Top
2 Internal Layers
Bottom
Copper Pattern
Thickness
Copper Pattern
Thickness
Copper Pattern
Thickness
Footprints and Traces
70μm
74.2mm x 74.2mm
35μm
74.2mm x 74.2mm
70μm
Recommended Operating Ranges
Parameter
Power Supply Voltage
DC/DC Oscillation Frequency
Symbol
Range
Unit
VCC
9.0 to 35.0
V
fsw
50 to 1000
kHz
Effective Range of ADIM Signal
VADIM
0.2 to 3.0
V
PWM Input Frequency
FPWM
90 to 2000
Hz
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
4/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
Electrical Characteristics
(Unless otherwise specified VCC=24V Tj=25°C)
Parameter
Symbol
Min
Typ
Max
Unit
Conditions
Circuit Current
ICC
－
3.3
6.6
mA
VSTB=3.0V, PWM=3.0V
Circuit Current (standby)
IST
－
40
80
μA
VSTB=0V
VCC=SWEEP UP
【Total Current Consumption】
【UVLO Block】
Operation Voltage（VCC）
VUVLO_VCC
6.5
7.5
8.5
V
Hysteresis Voltage（VCC）
VUHYS_VCC
150
300
600
mV
VUVLO
2.88
3.00
3.12
V
UVLO Release Voltage
UVLO Hysteresis Voltage
VCC=SWEEP DOWN
VUVLO=SWEEP UP
VUHYS
250
300
350
mV
VUVLO=SWEEP DOWN
IVUVLO_LK
-2
0
2
μA
VUVLO=4.0V
ISENSE Threshold Voltage 1
VLED1
0.225
0.233
0.242
V
VADIM=0.7V
ISENSE Threshold Voltage 2
VLED2
0.656
0.667
0.677
V
VADIM=2.0V
ISENSE Threshold Voltage 3
VLED3
0.988
1.000
1.012
V
ISENSE Clamp Voltage
VLED4
0.990
1.015
1.040
V
FCT
142.5
150
157.5
kHz
VADIM=3.0V
VADIM=3.3V
(as masking analog dimming)
RT=100kΩ
V
RT=SWEEP DOWN
UVLO Pin Leak Current
【DC/DC Block】
Oscillation Frequency
RT Short Protection Range
-0.3
-
VRT
1.6
2.0
2.4
V
RT=100kΩ
DMAX_DUTY
90
95
99
%
RT=100kΩ
RON_GSO
2.5
5.0
10.0
Ω
RON_GSI
2.0
4.0
8.0
Ω
ISSSO
-3.75
-3.0
-2.25
μA
RT Terminal Voltage
GATE Pin MAX DUTY Output
GATE Pin ON Resistance
(as source)
GATE Pin ON Resistance
(as sink)
SS Pin Source Current
VRT_DET
VRT
×90%
SS Pin ON Resistance at OFF
VSS=2.0V
RSS_L
-
3.0
5.0
kΩ
VSS_END
3.52
3.70
3.88
V
SS=SWEEP UP
FB Source Current
IFBSO
-115
-100
-85
μA
FB Sink Current
IFBSI
85
100
115
μA
VISENSE=0.2V, VADIM=3.0V,
VFB=1.0V
VISENSE=2.0V, VADIM=3.0V,
VFB=1.0V
Soft Start Ended Voltage
【DC/DC Block】
【DC/DC Protection Block】
OCP Detect Voltage1
VCS1
360
400
440
mV
OCP Detect Voltage2
VCS2
0.85
1.00
1.15
V
CS=SWEEP UP
VOVP SWEEP UP
OVP Detect Voltage
CS=SWEEP UP, Pulse by pulse
VOVP
2.88
3.00
3.12
V
OVP Detect Hysteresis
VOVP_HYS
150
200
250
mV
VOVP SWEEP DOWN
OVP Pin Leak Current
IOVP_LK
-2
0
2
μA
VOVP=4.0V, VSTB=3.0V
【LED Protection Block】
LED OCP Detect Voltage
VLEDOCP
2.88
3.00
3.12
V
VISENSE=SWEEP UP
VFBH
3.84
4.00
4.16
V
VFB=SWEEP UP
Over Boost Detection Voltage
【Dimming Block】
ILADIM
-2
0
2
μA
VADIM=2.0V
IL_ISENSE
-2
0
2
μA
VISENSE=4.0V
RON_DIMSO
5.0
10.0
20.0
Ω
RON_DIMSI
4.0
8.0
16.0
Ω
ADIM Pin Leak Current
ISENSE Pin Leak Current
DIMOUT Source ON
Resistance
DIMOUT Sink ON Resistance
【REG90 Block】
REG90 Output Voltage 1
VREG90_1
8.91
9.00
9.09
V
IO=0mA
REG90 Output Voltage 2
VREG90_2
8.865
9.00
9.135
V
IO=-15mA
REG90 Available Current
| IREG90 |
15
-
-
mA
REG90_UVLO Detect Voltage
VREG90_TH
5.22
6.00
6.78
V
REG90 Discharge Resistance
VREG90_DIS
13.2
22.0
30.8
kΩ
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
5/34
VREG90=SWEEP DOWN,
VSTB=0V
STB=ON->OFF, VREG90=8.0V,
PWM=L
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
Electrical Characteristics
(Unless otherwise specified VCC=24V Tj=25°C)
Parameter
Symbol
Min
Typ
Max
Unit
STB Pin HIGH Voltage
VSTBH
2.0
-
18
V
STB Pin LOW Voltage
VSTBL
-0.3
-
0.8
V
STB Pull Down Resistance
RSTB
600
1000
1400
kΩ
Conditions
【STB Block】
VSTB=3.0V
【PWM Block】
PWM Pin HIGH Voltage
VPWM_H
1.5
-
18
V
PWM Pin LOW Voltage
VPWM_L
-0.3
-
0.8
V
RPWM
600
1000
1400
kΩ
PWM Pin Pull Down Resistance
VPWM=3.0V
【DUTYON Block】
DUTYON Pin HIGH Voltage
VDTYON_H
1.5
-
18
V
DUTYON Pin LOW Voltage
DUTYON Pin Pull Down
Resistance
【Over Duty Protection Block】
PWM ODP Protection Detect
Duty
VDTYON_L
-0.3
-
0.8
V
RDTYON
600
1000
1400
kΩ
VDUTYON=3.0V
DODP
-
35
-
%
FPWM=120Hz, DUTYP=341kΩ
DUTYP Short Protection Range
VDTYP_DET
-0.3
-
×90%
V
DUTYP=SWEEP DOWN
VDTYP
1.6
2.0
2.4
V
DUTYP=100kΩ
DUTYP Terminal Voltage
VDUTYP
【Filter Block】
Abnormal Detection Timer
AUTO Timer
tCP
-
20
-
tAUTO
-
163
-
ms
ms
VFAILL
0.25
0.5
1.0
V
FCT=800kHz
FCT=800kHz
【FAIL Block 】
FAIL Pin LOW Voltage
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
6/34
IFAIL=1mA
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
4.0
80
3.5
70
3.0
60
2.5
50
ISTB[uA]
ICC[mA]
Typical Performance Curves (Reference data)
2.0
STB=0V
PWM=0V
Ta=25°C
40
30
1.5
STB=3.0V
PWM=3.0V
Ta=25°C
20
1.0
STB=3.0V
PWM=3.0V
Ta=25°C
0.5
10
0
0.0
10
15
20
25
VCC[V]
30
10
35
Figure 5. Operating circuit current
15
20
25
VCC[V]
30
35
Figure 6. Standby circuit current
1.4
100
ISENSE Feecback Voltage[V]
1.2
Duty Cycle[%]
80
60
40
20
VCC=24V
Ta=25°C
1.0
0.8
0.6
0.4
VCC=24V
Ta=25°C
VCC=24V
Ta=25°C
0.2
0.0
0
0
1
2
VFB[V]
3
0
4
Figure 7. Duty cycle vs FB character
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
1
2
VADIM[V]
3
4
Figure 8. ISENSE feedback voltage vs ADIM character
7/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
Pin Descriptions
○Pin 1: VCC
This is the power supply pin of the IC. Input range is from 9V to 35V.
The operation starts at more than 7.5V(Typ) and shuts down at less than 7.2V(Typ).
○Pin 2: STB
This is the ON/OFF setting terminal of the IC.
At startup, internal bias starts at high level, and then PWM DCDC boost starts after PWM rise edge inputs.
Note: IC status (IC ON/OFF) transits depending on the voltage inputted to STB terminal. Avoid the use of intermediate
level (from 0.8V to 2.0V).
○Pin 3: OVP
The OVP terminal is the input for over-voltage protection. If OVP is more than 3.0V(Typ), the over-voltage protection
(OVP) will work. At the moment of these detections, it sets GATE=L, DIMOUT=L and starts to count up the abnormal
interval. If OVP detection continued to count four GATE clocks, IC's operation will be stop. (Please refer to "OVP
Detection" Timing Chart on Page26)
The OVP pin is high impedance, because the internal resistance is not connected to a certain bias.
Even if OVP function is not used, pin bias is still required because the open connection of this pin is not a fixed potential.
The setting example is separately described in the ”OVP Setting" section on Page16.
○Pin 4: UVLO
Under Voltage Lock Out pin is the input voltage of the power stage. , IC starts the boost operation if UVLO is more than
3.0V(Typ) and stops if lower than 2.7V(Typ).
The UVLO pin is high impedance, because the internal resistance is not connected to a certain bias.
Even if UVLO function is not used, pin bias is still required because the open connection of this pin is not a fixed
potential.
The setting example is separately described in the ”UVLO Setting" section on Page15
○Pin 5: SS
This is the pin which sets the soft start interval of DC/DC converter. It performs the constant current charge of 3.0 μA(Typ)
to external capacitance Css. The switching duty of GATE output will be limited during 0V to 3.7V(Typ) of the SS voltage.
So the soft start interval Tss can be expressed as follows
TSS 1.23 106 CSS [sec]
CSS: the external capacitance of the SS pin.
The logic of SS pin asserts low is defined as the DC/DC operation stop state after protection function or PWM is not input
high level after STB reset release. When SS capacitance is under 1nF, take note if the in-rush current during startup is
too large, or if over boost detection (FBMAX) mask timing is too short.
Please refer to soft start behavior in the “Timing Chart" section on Page13.
○Pin 6: DUTYON
This is the ON/OFF setting terminal of the LED PWM Over Duty Protection (ODP). By adjusting DUTYON input voltage, it
is ON/OFF of the ODP adjusted.
State
DUTYON input voltage
ODP=ON
DUTYON= -0.3V to +0.8V
ODP=OFF
DUTYON= 1.5V to 18.0V
○Pin 7: PWM
This is the PWM dimming signal input terminal. The high / low level of PWM pins are the following.
State
PWM input voltage
PWM=H
PWM= 1.5V to 18.0V
PWM=L
PWM= ‐0.3V to +0.8V
○Pin 8: FAIL
This is FAIL signal output (OPEN DRAIN) pin. At normal operation, NMOS will be in ON (500 ohm Typ) state, during
abnormality detection NMOS will be in OPEN state (OFF).
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
8/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
○Pin 9: ADIM
This is the input pin for analog dimming signal. The ISENSE feedback point is set as 1/3 of this pin bias. If more than
3.0V(Typ) is input, ISENSE feedback voltage is clamped to limit to flow LED large current. In this condition, the input
current is caused. Please refer to terminal explanation.
○Pin 10: RT
This is the DC/DC switching frequency setting pin. DCDC frequency is decided by connected resistor.
○The relationship between the frequency and RT resistance value (ideal)
R RT
15000
[k]
f SW [kHz]
The oscillation setting ranges from 50kHz to 1000kHz.
The setting example is separately described in the ”DCDC Oscillation Frequency Setting” section on Page15
○Pin 11: DUTYP
This is the ODP setting pin. The ODP (Over Duty Protection) is the function to limit DUTY of LED PWM frequency f PWM by
ODP detection Duty (ODPduty) set by resistance (RDUTY) connected to DUTYP pin.
○Relationship between LED PWM frequency fPWM, ODP Detection Duty and DUTYP resistance (ideal)
RDUTYP
1172 ODPduty[%]
f PWM [ Hz]
[k]
The RDUTYP setting ranges from 15kΩ to 1MΩ.
The setting example is separately described in the ”ODP Setting” section on Page16.
○Pin 12: FB
This is the output terminal of error amplifier.
FB pin rises with the same slope as the SS pin during the soft-start period.
After soft -start completion (SS>3.7V(Typ)), it operates as follows.
When PWM=H, it detects ISENSE terminal voltage and outputs error signal compared to analog dimming signal (ADIM).
When PWM=L, IC holds the OVP voltage at the edge of PWM=H to L, and operates to hold the adjacent voltage. Please
refer to “Timing Chart” section
It detects over boost (FBMAX) over FB=4.0V(Typ). After the SS completion, if FB>4.0V and PWM=H continues 4clk GATE,
the CP counter starts. After that, only the FB>4.0V is monitored, When CP counter reaches 16384clk (214clk), IC's
operation will be stop. (Please refer to “Timing Chart” section on Page27.)
The loop compensation setting is described in section "Loop Compensation" on Page21.
○Pin 13: ISENSE
This is the input terminal for the current detection. Error amplifier compares
ISENSE voltage and the lower voltage between 1/3 of the ADIM (analog
dimming terminal) voltage and 1.015V(Typ) for FB voltage control.
And this terminal detects abnormal LED's over-current when ISENSE voltage
continues over 3.0V(Typ) during 4CLKs (equivalent to 40us at fosc = 100kHz),
DC/DC operation becomes stop. (Please refer to “Timing Chart” section on Page
28.)
VOUT
BD9411
DIMOUT
Error amp Vth[V]
Error AMP
+ 1.015V
+
1/3
1.015V
1.0V
ISENSE
ADIM
Rs
FB
Gain=1/3
67mV
0
0.2
3.0
ADIM[V]
Figure 9. Relationship of the feedback voltage and ADIM
Figure 10. ISENSE terminal circuit example
○Pin 14: GND
This is the GND pin of the IC.
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
9/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
○Pin 15: DIMOUT
This is the output pin for external dimming NMOS. The table below shows the rough output
logic of each operation state, and the output H level is REG90. Please refer to “Timing
Chart” section for detailed explanations, because DIMOUT logic has an exceptional
behavior. Please insert the resistor RDIM between the dimming MOS gate to improve the
over shoot of LED current, as PWM turns from low to high.
VOUT
REG90
DIMOUT
Status
DIMOUT output
Normal
Same logic to PWM
Abnormal
GND Level
RDIM
ISENSE
BD9411
Figure 11. DIMOUT terminal circuit
example
○Pin 16: GATE
This is the output terminal for driving the gate of the boost MOSFET. The high level is REG90. Frequency can be set by
the resistor connected to RT. Refer to pin description for the frequency setting.
○Pin 17: CS
The CS pin has two functions.
VIN
1. DC / DC current mode Feedback terminal
The inductor current is converted to the CS pin voltage by the sense resistor R CS.
This voltage compared to the voltage set by error amplifier controls the output
pulse.
BD9411
2. Inductor current limit (OCP) terminal
Id
GATE
The CS terminal also has an over current protection (OCP). If the voltage is more
than 0.4V(Typ), the switching operation will be stopped compulsorily. And the
CS
next boost pulse will be restarted to normal frequency.
In addition, the CS voltage is more than 1.0V(Typ) during 4CLKs GATE operation,
CCS
RCS
IC operation will be stop. As above OCP operation, if the current continues to flow
GND
nevertheless GATE=L because of the destruction of the boost MOS, IC will stops
the operation completely.
Figure 12. CS terminal circuit example
Both of the above functions are enabled after 300ns (Typ) when GATE pin
asserts high, because the Leading Edge Blanking function (LEB) is included into this IC to prevent the effect of noise.
Please refer to “OCP Setting / Calculation Method for the Current Rating of DCDC Parts” section on Page18, for detailed
explanation.
If the capacitance CCS in the right figure is increased to a micro order, please be careful that the limited value of NMOS
drain current Id is more than the simple calculation. Because the current Id flows not only through RCS but also through
CCS, as the CS pin voltage moves according to Id.
10
8
VREG90[V]
○Pin 18: REG90
This is the 9.0V(Typ) output pin. Available current is 15mA
(min).
The characteristic of VCC line regulation at REG90 is shown as
figure. VCC must be used in more than 10.5V for stable 9V
output.
Please place the ceramic capacitor connected to REG90 pin
(1.0μF to 10μF) closest to REG90-GND pin.
6
4
2
0
0
5
10
15
20
VCC[V]
25
30
Figure 13. REG90 line regulation
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
10/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
35
BD9411F
List of The Protection Function Detection Condition (Typ Condition)
Detect condition
Protect
Detection
pin
function
Detection condition
PWM
SS
Release
condition
Timer
operation
14
Protection Type
Immediately auto-restart
after detection
(Judge periodically
whether normal or not)
Immediately auto-restart
after detection
(Judge periodically
whether normal or not)
FBMAX
FB
FB > 4.0V
H(4clk)
SS>3.7V
FB < 4.0V
2 clk
LED OCP
ISENSE
ISENSE > 3.0V
-
-
ISENSE < 3.0V
4clk
RT GND
SHORT
RT
RT5V
-
-
Release
RT=HIGH
NO
Restart by release
UVLO
UVLO
UVLO3.0V
NO
Restart by release
REG90UVLO
REG90
REG906.5V
NO
Restart by release
VCCUVLO
VCC
VCC7.5V
NO
OVP
OVP
OVP>3.0V
-
-
OVP0.4V
-
-
-
NO
Pulse by pulse
4clk
Immediately auto-restart
after detection
(Judge periodically
whether normal or not)
NO
Restart by release
NO
Restart by release
NO
Cycle by cycle
OCP
detection2
DUTYP GND
SHORT
DUTYP HIGH
SHORT
CS
CS>1.0V
-
-
DUTYP
DUTYP 5V
-
-
PWM
DUTYON=H
and
PWM on duty > setting
duty by DUTYP resistor
H
-
ODP(*1)
CS0, the operation mode is CCM (Continuous Current Mode),
otherwise the mode is DCM (Discontinuous Current Mode).
(t)
（V)
0.4V
VCS[V]
I min
（A)
I [ A]
I IN [ A] L
or 0
2
VCSpeak
As this VCSpeak reaches 0.4V(Typ), the DCDC output stops the switching.
Therefore, RCS value is necessary to meet the condition below.
(t)
RCS I peak[V ] 0.4[V ]
Figure 26. Coil current waveform
(the current rating of the external DCDC parts)
The peak current as the CS voltage reaches OCP level (0.4V (Typ)) is defined as Ipeak_det.
I peak _ det
0.4[V ]
[ A]
RCS []
… (2)
The relationship among Ipeak (equation (1)), Ipeak_det (equation (2)) and the current rating of parts is required to meet the
following
I peak I peak _ det The current rating of parts
Please make the selection of the external parts such as FET, Inductor, diode meet the above condition.
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
18/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
[setting example]
Output voltage = VOUT [V] = 40V
LED total current = IOUT [A] = 0.48V
DCDC input voltage of the power stage = VIN [V] = 24V
Efficiency of DCDC =η[%] = 90%
Averaged input current IIN is calculated as follows.
I IN [ A]
VOUT [V ] I OUT [ A] 40[V ] 0.48[ A]
0.89 [ A]
VIN [V ] [%]
24[V ] 90[%]
If the switching frequency, fSW = 200kHz, and the inductor, L=100μH, the ripple current of the inductor L (ΔIL[A]) can be
calculated as follows.
ΔI L
(VOUT [V ] VIN [V ]) VIN [V ]
(40[V ] 24[V ]) 24[V ]
0.48 [ A]
L[ H ] VOUT [V ] f SW [ Hz]
100 10 6 [ H ] 40[V ] 200 10 3 [ Hz]
Therefore the inductor peak current, Ipeak is
I peak I IN [ A]
IL[ A]
0.48[ A]
[ A] 0.89[ A]
1.13 [ A]
2
2
…calculation result of the peak current
If Rcs is assumed to be 0.3Ω
VCS peak Rcs Ipeak 0.3[] 1.13[ A] 0.339 [V ] 0.4V
…RCS value confirmation
The above condition is met.
And Ipeak_det, the current OCP works, is
I peak _ det
0.4[V ]
1.33 [ A]
0.3[]
If the current rating of the used parts is 2A,
I peak I peak _ det The current rating
1.13[ A] 1.33[ A] 2.0[ A]
…current rating confirmation
of DCDC parts
This inequality meets the above relationship. The parts selection is proper.
And IMIN, the bottom of the IL ripple current, can be calculated as follows.
I MIN I IN [ A]
I L [ A]
[ A] 1.13[ A] 0.48[ A] 0.65[ A] 0
2
This inequality implies that the operation is continuous current mode.
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
19/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
2. Inductor Selection
The inductor value affects the input ripple current, as shown the "OCP setting" on Page18.
ΔI L
Δ IL
I IN
VIN
IL
(VOUT [V ] VIN [V ]) VIN [V ]
[ A]
L[ H ] VOUT [V ] f SW [ Hz]
VOUT [V ] I OUT [ A]
[ A]
VIN [V ] [%]
Ipeak I IN [ A]
L
VOUT
RCS
COUT
I L [ A]
[ A]
2
Where
L: coil inductance [H]
VOUT: DCDC output voltage [V]
VIN: input voltage [V]
IOUT: output load current (the summation of LED current) [A]
IIN: input current [A]
fSW: oscillation frequency [Hz]
Figure 27. Inductor current waveform and diagram
In continuous current mode, ⊿IL is set to 30% to 50% of the output load current in many cases.
In using smaller inductor, the boost is operated by the discontinuous current mode in which the coil current returns to
zero at every period.
*The current exceeding the rated current value of inductor flown through the coil causes magnetic saturation, results in
decreasing in efficiency. Inductor needs to be selected to have such adequate margin that peak current does not
exceed the rated current value of the inductor.
*To reduce inductor loss and improve efficiency, inductor with low resistance components (DCR, ACR) needs to be
selected
3. Output Capacitance Cout Selection
Output capacitor needs to be selected in consideration of equivalent series resistance
VIN
required to even the stable area of output voltage or ripple voltage.
IL
LED current may not be flown due to decrease in LED terminal voltage if output ripple
L
VOUT
RESR
RCS
Be aware that set
COUT
Figure 28. Output capacitor diagram
component is high.
Output ripple voltage ⊿VOUT is determined by Equation (4):
ΔVOUT ΔI L RESR
[V ] ・・・・・
(4)
When the coil current is charged to the output capacitor as MOS turns off, much output
ripple is caused. Much ripple voltage of the output capacitor may cause the LED current
ripple.
* Rating of capacitor needs to be selected to have adequate margin against output voltage.
*To use an electrolytic capacitor, adequate margin against allowable current is also necessary. Be aware that the LED
current is larger than the set value transitionally in case that LED is provided with PWM dimming especially.
4. MOSFET Selection
There is no problem if the absolute maximum rating is larger than the rated current of the inductor L, or is larger than
the sum of the tolerance voltage of COUT and the rectifying diode VF. The product with small gate capacitance (injected
charge) needs to be selected to achieve high-speed switching.
* One with over current protection setting or higher is recommended.
* The selection of one with small on resistance results in high efficiency.
5. Rectifying Diode Selection
A schottky barrier diode which has current ability higher than the rated current of L, reverse voltage larger than the
tolerance voltage of COUT, and low forward voltage VF especially needs to be selected.
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
20/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
Loop Compensation
A current mode DCDC converter has each one pole (phase lag) f p due to CR filter composed of the output capacitor and
the output resistance (= LED current) and zero (phase lead) fZ by the output capacitor and the ESR of the capacitor.
Moreover, a step-up DCDC converter has RHP zero (right-half plane zero point) fZRHP which is unique with the boost
converter. This zero may cause the unstable feedback. To avoid this by RHP zero, the loop compensation that the
cross-over frequency fc, set as follows, is suggested.
fc = fZRHP /5 (fZRHP: RHP zero frequency)
Considering the response speed, the calculated constant below is not always optimized completely. It needs to be
adequately verified with an actual device.
VOUT
VIN
ILED
L
-
VOUT
FB
gm
+
RESR
RCS
RFB1
C FB2
CFB1
COUT
Figure 29. Output stage and error amplifier diagram
i.
Calculate the pole frequency fp and the RHP zero frequency fZRHP of DC/DC converter
fp
I LED
[
Hz]
2 VOUT COUT
f ZRHP
Where ILED = the summation of LED current,
ii.
D
VOUT (1 D) 2
[
Hz]
2 L I LED
VOUT VIN (Continuous Current Mode)
VOUT
Calculate the phase compensation of the error amp output (f c = fZRHP/5)
f ZRHP RCS I LED
[
]
5 f p gm VOUT (1 D)
1
5
[F ]
2 RFB1 f C 2 RFB1 f ZRHP
RFB1
C FB1
gm 4.0 104 [S ]
Above equation is described for lighting LED without the oscillation. The value may cause much error if the quick
response for the abrupt change of dimming signal is required.
To improve the transient response, RFB1 needs to be increased, and CFB1 needs to be decreased. It needs to be
adequately verified with an actual device in consideration of variation from parts to parts since phase margin is
decreased.
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
21/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
Timing Chart
1. PWM Start up 1 (Input PWM Signal After Input STB Signal)
7 .5 V
VCC
STB
PWM
6 . 5V
REG 90
3 .7 V
SS
0 .4 V
0 .4 V
GATE
FAIL (Note1)
(At pull-up external voltage)
STATE
OFF
SS
STANDBY
(* 1) (*2)
(*3)
Normal
(*4)
STANDBY
(*5)
SS
(*6)
Figure 30. PWM Start up 1 (Input PWM Signal After Input STB Signal)
(*1)…REG90 starts up when STB is changed from Low to High. In the state where the PWM signal is not inputted, SS terminal
is not charged and DCDC doesn’t start to boost, either.
(*2)…When REG90 is more than 6.5V(Typ), the reset signal is released.
(*3)…The charge of the pin SS starts at the positive edge of PWM=L to H, and the soft start starts. And while the SS is less than
0.4V, the pulse does not output. The pin SS continues charging in spite of the assertion of PWM or OVP level.
(*4)…The soft start interval will end if the voltage of the pin SS, VSS reaches 3.7V(Typ). By this time, it boosts VOUT to the voltage
where the set LED current flows. The abnormal detection of FBMAX starts to be monitored.
(*5)…As STB=L, the boost operation is stopped instantaneously. (Discharge operation continues in the state of STB=L and
REGUVLO=L. Please refer to the "Turn Off" section on Page24)
(*6)…In this diagram, before the charge period is completed, STB is changed to High again. As STB=H again, the boost
operation restarts the next PWM=H. It is the same operation as the timing of (*2). (For capacitance setting of SS terminal,
please refer to the "Method of setting SS external capacitance" section on Page13.
(Note1) At FAIL terminal pull-up to external voltage, FAIL voltage is "H" until REG90 over 6.5V. (Initial FAIL's NMOS is "OFF"
before IC's circuit will operate).
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
22/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
2. PWM Start Up 2 (Input STB Signal after Inputted PWM Signal)
7 .5 V
VCC
STB
PWM
6 .5 V
REG 90
3 .7 V
0 .4 V
SS
0 .4 V
GATE
FAIL (Note1)
(At pull-up external voltage)
STATE
OFF
SS
(*1) (* 2)
NORMAL
(*3)
STANDBY
(*4)
SS
(*5)
Figure 31. PWM Start Up 2 (Input STB Signal after Inputted PWM Signal)
(*1)…REG90 starts up when STB=H.
(*2)…When REG90UVLO releases or PWM is inputted to the edge of PWM=L→H, SS charge starts and soft start period is
started. And while the SS is less than 0.4V, the pulse does not output. The pin SS continues charging in spite of the
assertion of PWM or OVP level.
(*3)…The soft start interval will end if the voltage of the pin SS, VSS reaches 3.7V(Typ). By this time, it boosts VOUT to the point
where the set LED current flows. The abnormal detection of FBMAX starts to be monitored.
(*4)…As STB=L, the boost operation is stopped instantaneously (GATE=L, SS=L). (Discharge operation works in the state of
STB=L and REG90UVLO=H. Please refer to the "Turn Off" section on Page24)
(*5)…In this diagram, before the discharge period is completed, STB is changed to High again. As STB=H again, operation will
be the same as the timing of (*1).
(Note1) At FAIL terminal pull-up to external voltage, FAIL voltage is "H" until STB change from "L" to "H". (Initial FAIL's NMOS is
"OFF" before IC's circuit will operate).
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
23/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
3. Turn Off
STB
PWM
REG 90
6 .0 V
REG 90 UVLO
DIMOUT
GATE
Vout
SS
FAIL (Note1)
(Pull-up to external voltage)
STATE
ON
Discharge
(*1)
OFF
(*2)
Figure 32. Turn Off
(*1)…As STB=H→L, boost operation stops and REG90 starts to discharge. The discharge curve is decided by REG90
discharge resistance and the capacitor of the REG90 terminal.
(*2)…While STB=L, REG90UVLO=H, DIMOUT becomes same as PWM. When REG90=9.0V is less than 6.0V(Typ), IC
becomes OFF state. VOUT is discharged completely until this time. It should be set to avoid a sudden brightness.
(Note1) At FAIL terminal pull-up to external voltage, FAIL voltage is "H" until STB change from "L" to "H". (Initial FAIL's NMOS is
"OFF" before IC's circuit will operate).
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
24/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
4. Soft Start Function
STB
PWM
UVLO
2 .7 V
3.0V
7 .2 V
VCCUVLO
7 .5 V
6.0V
REG 90 UVLO
6.5V
3 .0 V
OVP
2 .8 V
4clk
FAIL (Note1)
(At pull-up external voltage)
SS
(*1)
(*2)(* 3)
(* 4)
(* 5)
(* 6)
(* 7)
Figure 33. Soft Start Function
(*1)…The SS pin charge does not start by just STB=H. PWM=H is required to start the soft start. In the low SS voltage, the
GATE pin duty depends on the SS voltage. And while the SS is less than 0.4V, the pulse does not output.
(*2)…By the time STB=L, the SS pin is discharged immediately.
(*3)…As the STB recovered to STB=H, The SS charge starts immediately by the logic PWM=H in this chart.
(*4)…The SS pin is discharged immediately by the UVLO=L.
(*5)…The SS pin is discharged immediately by the VCCUVLO=L.
(*6)…The SS pin is discharged immediately by the REG90UVLO=L.
(*7)…The SS pin is not discharged by the abnormal detection for use timer Type protection such as OVP until the timer finish.
(Note1) At FAIL terminal pull-up to external voltage, FAIL voltage is "H" until STB change from "L" to "H". (Initial FAIL's NMOS is
"OFF" before IC's circuit will operate).
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
25/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
5. OVP Detection
STB
PWM
REG 90
3 .0 V
OVP
Abnormal
COUNTER
START
2 .8 V
2 .8 V
3 .0 V
3 .0 V
END
Less than
Gate 4count
RESET
START
START
Gate 4count
AUTO COUNTER
2 .8 V
Less than
Gate 4count
RESET
END
131072 count
START
SS
0 .4 V
GATE
DIMOUT
FAIL
STATE NORMAL
OVP
NORMAL
OVP
abnormal
(* 1)
(*2)
IC's operation stop and
AUTO COUNTER
NORMAL
OVP
abnormal
(*3)
NORMAL
abnormal
(* 4) (* 5)
(* 6)
(* 7)
Figure 34. OVP Detection
(*1)…As OVP is detected, the output GATE=L, DIMOUT=L, and the abnormal counter starts.
(*2)…If OVP is released within 4 clocks of abnormal counter of the GATE pin frequency, the boost operation restarts.
(*3)…As the OVP is detected again, the boost operation is stopped.
(*4)…As the OVP detection continues up to 4 count by the abnormal counter, IC's operation will be stop. After IC operation stop,
auto counter starts counting.
(*5)… Once IC operation stop, the boost operation doesn't restart even if OVP is released.
(*6)…When auto counter reaches 131072clk (217clk), IC will be auto-restarted. The auto restart interval can be calculated by the
external resistor of RT pin. (Please refer to the "Timer Latch Time setting, Auto-Restart Timer setting" section on Page17.)
(*7)…The operation of the OVP detection is not related to the logic of PWM.
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
26/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
6. FBMAX Detection
STB
PWM
REG 90
4.0V
4 .0 V
FB
GATE
・・・・・
・・・・・
① ② ③ ④
CP COUNTER
START
END
16384 count
AUTO COUNTER
END
131072 count
START
3 .7 V
SS
FAIL (Note1)
(At pull-up external voltage)
SS
STATE STANDBY
(* 1)
(* 2)
NORMAL
(*3)
CP COUNTOR
(*4)
IC's operation stop and
AUTO COUNTER
(*5)
SS
(* 6)
Figure 35. FBMAX Detection
(*2)…During the soft start, it is not judged to the abnormal state even if the FB=H(FB>4.0V(Typ)).
(*3)…When the PWM=H and FB=H, the abnormal counter doesn’t start immediately.
(*4)…The CP counter will start if the PWM=H and the FB=H detection continues up to 4 clocks of the GATE frequency. Once the
count starts, only FB level is monitored.
(*5)…When the FBMAX detection continues till the CP counter reaches 16384clk (214clk), IC's operation will be stop. The
operation stop interval can be calculated by the external resistor of RT pin. (Please refer to the "Timer Latch Time setting,
Auto-Restart Timer setting" section on Page17.)
(*6)…When auto counter reaches 131072clk (217clk), IC will be auto-restarted. The auto restart interval can be calculated by the
external resistor of RT pin. (Please refer to the "Timer Latch Time setting, Auto-Restart Timer setting" section on Page17.)
(Note1) At FAIL terminal pull-up to external voltage, FAIL voltage is "H" until STB change from "L" to "H". (Initial FAIL's NMOS is
"OFF" before IC's circuit will operate).
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
27/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
7. LED OCP Detection
STB
PWM
REG 90
3 .0 V
ISENSE
Abnormal
COUNTER
START
3. 0 V
Less than
4count
3 .0 V
START
RESET
3 .0 V
4count
3 .0 V
END
START
AUTO COUNTER
Less than
4count
3 .0 V
RESET
END
131072 count
START
SS
0 .4 V
GATE
DIMOUT
FAIL
STATE NORMAL
LEDOCP
NORMAL
abnormal
(*1)
(*2)
IC's operation stop and
AUTO COUNTER
LEDOCP
abnormal
(*3)
NORMAL
LEDOCP
NORMAL
abnormal
(*4) (*5)
(* 6)
(* 7)
Figure 36. LED OCP Detection
(*1)…If ISENSE>3.0V(Typ), LEDOCP is detected, and GATE becomes L. To detect LEDOCP continuously, The DIMOUT is
compulsorily high, regardless of the PWM dimming signal.
(*2)…When the LEDOCP releases within 4 counts of the GATE frequency, the boost operation restarts.
(*3) …As the LEDOCP is detected again, the boost operation is stopped.
(*4)…If the LEDOCP detection continues up to 4 counts of GATE frequency. IC's operation will be stop. After IC operation stop,
auto counter starts counting.
(*5)…Once IC's operation stop, the boost operation doesn't restart even if the LEDOCP releases.
(*6)…When auto counter reaches 131072clk (217clk), IC will be auto-restarted. The auto restart interval can be calculated by the
external resistor of RT pin. (Please refer to the "Timer Latch Time setting, Auto-Restart Timer setting" section on Page17.)
(*7)…The operation of the LEDOCP detection is not related to the logic of the PWM.
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
28/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
I/O Equivalent Circuits
OVP
100k
UVLO
OVP
50k
SS
UVLO
SS
3k
5V
5V
5V
RT
PWM
RT
DUTYON
PWM
100k
100k
5V
5V
1M
ADIM
DUTYON
1M
FB
DIMOUT / REG90
REG90
20k
ADIM
DIMOUT
FB
5V
100k
VCC
GATE / REG90 / CS
STB
GND
ISENSE
REG90
GATE
VCC
100k
STB
100k
20k
5V
5V
GND
ISENSE
1M
CS
DUTYP
FAIL
DUTYP
FAIL
500
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
29/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
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 pins.
2.
Power Supply Lines
Design the PCB layout pattern to provide low impedance supply lines. 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.
Ground Voltage
Ensure that no pins are at a voltage below that of the ground pin at any time, even during transient condition.
4.
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 maximum junction temperature rating be exceeded the rise in temperature of the chip may
result in deterioration of the properties of the chip. In case of exceeding this absolute maximum rating, increase the
board size and copper area to prevent exceeding the maximum junction temperature rating.
6.
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.
7.
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.
Operation Under Strong Electromagnetic Field
Operating the IC in the presence of a strong electromagnetic field may cause the IC to malfunction.
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.
10. 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.
11. Unused Input Pins
Input pins 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 pins should be connected to the
power supply or ground line.
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
30/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
Operational Notes – continued
12. 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.
Resistor
Transistor (NPN)
Pin A
Pin B
C
E
Pin A
N
P+
P
N
N
P+
N
Pin B
B
Parasitic
Elements
N
P+
N P
N
P+
B
N
C
E
Parasitic
Elements
P Substrate
P Substrate
GND
GND
Parasitic
Elements
GND
Parasitic
Elements
GND
N Region
close-by
Figure 37. Example of monolithic IC structure
13. 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.
14. Area of Safe Operation (ASO)
Operate the IC such that the output voltage, output current, and the maximum junction temperature rating are all
within the Area of Safe Operation (ASO).
15. 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 maximum junction temperature 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.
16. 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.
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
31/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
Ordering Information
B
D
9
4
1
Part Number
1
F
-
Package
F:SOP18
E2
Packaging and forming specification
E2: Embossed tape and reel
Marking Diagrams
SOP18(TOP VIEW)
Part Number Marking
BD9411F
LOT Number
1PIN MARK
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
32/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
Physical Dimension, Tape and Reel Information
Package Name
SOP18
(Max 11.55 (include.BURR))
(UNIT : mm)
PKG : SOP18
Drawing No. : EX115-5001
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
33/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
BD9411F
Revision History
Date
Revision
20.Feb. 2017
001
Changes
New Release
www.rohm.com
© 2017 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
34/34
TSZ02201-0T2T0C100250-1-2
20.Feb.2017 Rev.001
Notice
Precaution on using ROHM Products
1.
Our Products are designed and manufactured for application in ordinary electronic equipments (such as AV equipment,
OA equipment, telecommunication equipment, home electronic appliances, amusement equipment, etc.). If you
(Note 1)
intend to use our Products in devices requiring extremely high reliability (such as medical equipment
, 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
CLASSⅡb
CLASSⅢ
CLASSⅢ
CLASSⅣ
CLASSⅢ
2.
ROHM designs and manufactures its Products subject to strict quality control system. However, semiconductor
products can fail or malfunction at a certain rate. Please be sure to implement, at your own responsibilities, adequate
safety measures including but not limited to fail-safe design against the physical injury, damage to any property, which
a failure or malfunction of our Products may cause. The following are examples of safety measures:
[a] Installation of protection circuits or other protective devices to improve system safety
[b] Installation of redundant circuits to reduce the impact of single or multiple circuit failure
3.
Our Products are designed and manufactured for use under standard conditions and not under any special or
extraordinary environments or conditions, as exemplified below. Accordingly, ROHM shall not be in any way
responsible or liable for any damages, expenses or losses arising from the use of any ROHM’s Products under any
special or extraordinary environments or conditions. If you intend to use our Products under any special or
extraordinary environments or conditions (as exemplified below), your independent verification and confirmation of
product performance, reliability, etc, prior to use, must be necessary:
[a] Use of our Products in any types of liquid, including water, oils, chemicals, and organic solvents
[b] Use of our Products outdoors or in places where the Products are exposed to direct sunlight or dust
[c] Use of our Products in places where the Products are exposed to sea wind or corrosive gases, including Cl2,
H2S, NH3, SO2, and NO2
[d] Use of our Products in places where the Products are exposed to static electricity or electromagnetic waves
[e] Use of our Products in proximity to heat-producing components, plastic cords, or other flammable items
[f] Sealing or coating our Products with resin or other coating materials
[g] Use of our Products without cleaning residue of flux (even if you use no-clean type fluxes, cleaning residue of
flux is recommended); or Washing our Products by using water or water-soluble cleaning agents for cleaning
residue after soldering
[h] Use of the Products in places subject to dew condensation
4.
The Products are not subject to radiation-proof design.
5.
Please verify and confirm characteristics of the final or mounted products in using the Products.
6.
In particular, if a transient load (a large amount of load applied in a short period of time, such as pulse. is applied,
confirmation of performance characteristics after on-board mounting is strongly recommended. Avoid applying power
exceeding normal rated power; exceeding the power rating under steady-state loading condition may negatively affect
product performance and reliability.
7.
De-rate Power Dissipation depending on ambient temperature. When used in sealed area, confirm that it is the use in
the range that does not exceed the maximum junction 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
© 2015 ROHM Co., Ltd. All rights reserved.
Rev.003
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
A two-dimensional barcode 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
© 2015 ROHM Co., Ltd. All rights reserved.
Rev.003
Datasheet
General Precaution
1. Before you use our Pro ducts, you are requested to care fully read this document and fully understand its contents.
ROHM shall n ot be in an y way responsible or liabl e for fa ilure, malfunction or acci dent arising from the use of a ny
ROHM’s Products against warning, caution or note contained in this document.
2. All information contained in this docume nt is current as of the issuing date and subj ect to change without any prior
notice. Before purchasing or using ROHM’s Products, please confirm the la test information with a ROHM sale s
representative.
3.
The information contained in this doc ument is provi ded on an “as is” basis and ROHM does not warrant that all
information contained in this document is accurate an d/or error-free. ROHM shall not be in an y way responsible or
liable for an y damages, expenses or losses incurred b y you or third parties resulting from inaccur acy or errors of or
concerning such information.
Notice – WE
© 2015 ROHM Co., Ltd. All rights reserved.
Rev.001
