Datasheet
LED Drivers for LCD Backlights
1ch Boost up type
White LED Driver for large LCD
BD9409F
Key Specifications
1.1 General Description
Operating power supply voltage range:
11.5V to 35.0V
Oscillator frequency of DCDC: 150kHz (RT=100kΩ)
Operating Current:
2.8 mA(Typ.)
Operating temperature range:
-40°C to +105°C
BD9409F is a high efficiency driver for white LEDs and is
designed for large LCDs. BD9409F has a boost DCDC
converter that employs an array of LEDs as the light
source.
BD9409F 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.
1.2 Package(s)
W(Typ) x D(Typ) x H(Max)
10.00mm x 6.20mm x 1.71mm
Pin pitch 1.27mm
SOP16
Features
DCDC converter with current mode
LED protection circuit (Over boost protection(FB_H),
LED OCP protection)
Over-voltage protection (OVP) for the output voltage
Vout
Adjustable soft start
Adjustable oscillation frequency of DCDC
UVLO detection for the input voltage of the power
stage
PWM Dimming and MS Dimming.
Applications
Figure 1.
TV, Computer Display, LCD Backlighting
SOP16
Typical Application Circuit
Vout
VCC
VIN
VCC
UVLO
OVP
REG90
STB
GATE
RT
CS
SS
FAIL
DIMOUT
PWM
ISENSE
FB
MS
Rs
GND
Figure 2. Typical Application Circuit
○Product structure：Silicon monolithic integrated circuit
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1.3 Pin Configuration
1
VCC
REG90
16
2
STB
CS
15
3
OVP
GATE
14
4
UVLO
DIMOUT
13
5
SS
GND
12
6
PWM
ISENSE
11
7
FAIL
FB
10
8
MS
RT
9
Figure 3. Pin Configuration
1.4 Pin Descriptions
No.
Pin name
Function
1
VCC
Power supply pin
2
STB
IC ON/OFF pin
3
OVP
Over voltage protection detection pin
4
UVLO
Under voltage lock out detection pin
5
SS
6
PWM
External PWM dimming signal input pin
7
FAIL
Error detection output pin(Active High)
8
MS
Mode Select Dimming input pin.
9
RT
DC/DC switching frequency setting pin
10
FB
Error amplifier output pin
11
ISENSE
12
GND
13
DIMOUT
Dimming signal output for NMOS
14
GATE
15
CS
16
REG90
DC/DC switching output pin
DC/DC output current detect pin,
OCP input pin
9.0V output voltage pin
Soft start setting pin
LED current detection input pin
-
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1.5 Block Diagram
VCC
VIN
VCC
REG90
UVLO
MS_STB
COMP
OVP
VCC
UVLO
VREG
STB
UVLO
OVP
TSD
REG90
UVLO
1MΩ
REG90
+
RT
OSC
PWM
COM
P
GATE
CONTROL
LOGIC
CS
SS
LEB
Current
sense
SS
REG90
SS-FB
clamper
VCC
DIMOUT
Fail
detect
3kΩ
LEDOCP
AutoRestart
Control
-
PWM
ERROR
amp
1MΩ
ISENSE
+
FAIL
MS_STB
COMP
Rs
FB
OverBoost
MS
CS DET Level
Selecter
Package:SOP16
GND
Figure 4. Block Diagram
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1.6 Absolute Maximum Ratings (Ta=25°C)
Parameter
Power Supply Voltage
SS, RT, ISENSE, FB, CS
Pin Voltage
REG90, DIMOUT, GATE
Pin Voltage
OVP, UVLO, PWM, MS, STB
Pin Voltage
Symbol
VCC
Rating
Unit
-0.3 to +36
V
SS, RT, ISENSE, FB, CS
-0.3 to +7
V
REG90, DIMOUT, GATE
-0.3 to +13
V
OVP, UVLO, PWM, MS,
STB
-0.3 to +20
V
FAIL
-0.3 ~ VCC+0.3
V
Pd
0.74 (*1)
W
Topr
-40 to +105
°C
Tjmax
150
°C
Tstg
-55 to +150
°C
FAIL Pin Voltage
Power Dissipation
Operating Temperature Range
Junction Temperature
Storage Temperature Range
(*1) Derate by 5.92mW/°C when operating above Ta=25°C.. (Mounted on 1-layer 114.3mm x 76.2mm x 1.57mm board)
1.7 Recommended Operating Ranges
Parameter
Symbol
Range
VCC
11.5 to 35.0
V
fsw
50 to 1000
kHz
FPWM
90 to 2000
Hz
Power Supply Voltage
DC/DC Oscillation Frequency
PWM Input Frequency
Unit
1.8 Electrical Characteristics 1/2 (Unless otherwise specified VCC=24V Ta=25°C)
Parameter
Symbol
Min
Typ
Max
Unit
Conditions
Icc
-
2.8
5.6
mA
VSTB=3.0V, PWM=3.0V
【Total Current Consumption】
Circuit Current
Circuit Current (standby)
IST
-
60
120
μA
VSTB=0V
IST_MS
-
60
120
μA
VSTB=3.0V, MS=0V
Operation Voltage（VCC）
VUVLO_VCC
9.5
10.5
11.5
V
VCC=SWEEP UP
Hysteresis Voltage（VCC）
Circuit Current (MS standby)
【UVLO Block】
VUHYS_VCC
130
270
540
mV
VCC=SWEEP DOWN
UVLO Release Voltage
VUVLO
2.88
3.00
3.12
V
VUVLO=SWEEP UP
UVLO Hysteresis Voltage
VUHYS
250
300
350
mV
VUVLO=SWEEP DOWN
UVLO_LK
-2
0
2
μA
VUVLO=4.0V
ISENSE Threshold Voltage 1
VLED1
0.327
0.341
0.355
V
MS=1V(75% dimming)
ISENSE Threshold Voltage 2
VLED2
0.441
0.455
0.470
V
MS=2V(100% dimming)
ISENSE Threshold Voltage 3
VLED3
0.483
0.500
0.518
V
MS=3V(110% dimming)
MS Threshold Voltage 0
VMS0
-0.25
0.00
0.25
V
VSTB=3.0V, PWM=3.0V
MS Threshold Voltage 1
VMS1
0.70
1.00
1.25
V
VSTB=3.0V, PWM=3.0V
MS Threshold Voltage 2
VMS2
1.70
2.00
2.25
V
VSTB=3.0V, PWM=3.0V
MS Threshold Voltage 3
VMS3
2.70
3.00
10.0
V
VSTB=3.0V, PWM=3.0V
FCT
142.5
150
157.5
kHz
V
RT=SWEEP DOWN
UVLO Pin Leak Current
【DC/DC Block】
Oscillation Frequency
RT Short Protection Range
RT_DET
-0.3
-
VRT
×90%
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
1.6
2.0
2.4
V
RT=100kΩ
MAX_DUTY
90
95
99
%
RT=100kΩ
RONSO
2.5
5.0
10.0
Ω
RONSI
2.0
4.0
8.0
Ω
ISSSO
-3.75
-3.00
-2.25
μA
SS Pin ON Resistance at OFF
Soft Start Ended Voltage
RT=100kΩ
RSS_L
-
3.0
5.0
kΩ
VSS_END
3.52
3.70
3.88
V
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SS=SWEEP UP
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1.8 Electrical Characteristics 2/2 (Unless otherwise specified VCC=24V Ta=25°C)
Parameter
Symbol
Min
Typ
Max
Unit
Conditions
FB Source Current
IFBSO
-115
-100
-85
μA
FB Sink Current
IFBSI
85
100
115
μA
VCS1
360
400
440
mV
CS=SWEEP UP
OCP Latch OFF Detect Voltage
VCS2
0.85
1.00
1.15
V
CS=SWEEP UP
OVP Detect Voltage
VOVP
2.88
3.00
3.12
V
VOVP SWEEP UP
OVP Detect Hysteresis
VOVP_HYS
150
200
250
mV
VOVP SWEEP DOWN
OVP Pin Leak Current
OVP_LK
-1.8
0
1.8
μA
VOVP=4.0V, VSTB=3.0V
VLEDOCP
2.88
3.00
3.12
V
VISENSE=SWEEP UP
VFBH
3.84
4.00
4.16
V
VFB=SWEEP UP
ILMS
-1.8
0
1.8
μA
VMS=2.0V
IL_ISENSE
-2
0
2
μA
VISENSE=4.0V
RONSO
5.0
10.0
20.0
Ω
RONSI
4.0
8.0
16.0
Ω
VMS_H
0.70
-
20
V
MS=Sweep up
VMS_L
-0.25
-
0.25
V
MS=Sweep down
【DC/DC Block】
VISENSE=0.0V, VMS=3.0V,
VFB=1.0V
VISENSE=2.0V, VMS=3.0V,
VFB=1.0V
【DC/DC Protection Block】
OCP Detect Voltage
【LED Protection Block】
LED OCP Detect Voltage
Over Boost Detection Voltage
【Dimming Block】
MS Pin Leak Current
ISENSE Pin Leak Current
DIMOUT Source ON
Resistance
DIMOUT Sink ON Resistance
MS Pin HIGH Voltage
(Active mode)
MS Pin LOW Voltage
(Stand-by mode)
【REG90 Block】
REG90 Output Voltage 1
REG90_1
8.91
9.00
9.09
V
IO=0mA
REG90 Output Voltage 2
REG90 Available Source
Current
REG90_2
8.865
9.00
9.135
V
IO=-15mA
| IREG90 |
15
-
-
mA
REG90_UVLO Detect Voltage
REG90_TH
5.22
6.00
6.78
V
REG90 Discharge Resistance
REG90_DIS
13.2
22.0
30.8
kΩ
V
VREG90=SWEEP DOWN,
VSTB=0V
STB=MS=ON->OFF,
REG90=8.0V, PWM=H
【STB Block】
STB Pin HIGH Voltage
STBH
2.0
-
18
STB Pin LOW Voltage
STBL
-0.3
-
0.8
V
STB Pull Down Resistance
RSTB
600
1000
1400
kΩ
PWM Pin HIGH Voltage
PWM_H
1.5
-
18
V
PWM Pin LOW Voltage
PWM_L
-0.3
-
0.8
V
PWM Pin Pull Down Resistance
RPWM
600
1000
1400
kΩ
VPWM=3.0V
tCP
-
20
-
ms
FCT=200kHz
tAUTO
-
655
-
ms
FCT=200kHz
RFAIL
-
3.0
6.0
kΩ
CS=1.15V
VSTB=3.0V
【PWM Block】
【Filter Block】
Abnormal Detection Timer
AUTO Timer
【FAIL Block 】
Pull Up Resistance of
FAILB Pin Latch Off
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1.9 Typical Performance Curves (Reference data)
4.0
100
3.5
90
80
70
2.5
IST_MS[uA]
ICC[mA]
3.0
2.0
1.5
60
50
40
30
1.0
STB=MS=3.0V
PWM=3.0V
Ta=25°C
0.5
STB=3V, MS=0V
PWM=0V
Ta=25°C
20
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 MS
0.8
100
0.7
ISENSE Feecback Voltage[V]
Duty Cycle[%]
80
60
40
20
VCC=24V
Ta=25°C
0.6
0.5
0.4
0.3
― Sweep Up
… Sweep Down
0.2
0.1
VCC=24V
Ta=25°C
0.0
0
0
1
2
FB[V]
3
0
4
Figure 7. Duty cycle vs FB character
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MS[V]
3
4
5
Figure 8. ISENSE feedback voltage vs MS character
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2.1 Pin Descriptions
○Pin 1: VCC
This is the power supply pin of the IC. Input range is from 11.5V to 35V.
The operation starts at more than 10.5V(typ.) and shuts down at less than 10.2V(typ.).
○Pin 2: STB
This is the ON/OFF setting terminal of the IC. Input reset-signal to this terminal to reset IC from latch-off.
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 and MS 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 reaches latch off. (Please refer to “3.5.5 Timing Chart”)
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 section ”3.2.6 OVP Setting”.
○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 section ”3.2.5 UVLO Setting”
○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 latch-off state 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 section “3.5.4 Timing Chart ”.
○Pin 6: 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 7: FAIL
This is FAIL signal output (OPEN DRAIN) pin. At normal operation, PMOS will be OPEN state, during abnormality
detection PMOS will be in ON (3kohm typ.) state. And Pull Up to VCC.
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○Pin 8: MS
This is the input pin for analog dimming signal. In this condition, the input current is caused. Please refer to
terminal explanation.
Relationship between MS Voltage and ISENSE Voltage.
VMS =3V(2.70~10.0V)： VISENSE = 0.500V (110% dimming)
VMS =2V(1.70~2.25V)： VISENSE = 0.455V (100% dimming)
VMS =1V(0.70~1.25V)： VISENSE = 0.341V (75% dimming)
VMS =0V(-0.25~0.25V)： MS Stand-by Mode
ISENSE
Detect level[V]
0.500V
0.455V
0.341V
0
0 0.25V
0.70V
1.25V
1.70V
2.25V
10V
2.70V
MS[V]
Figure 9. MS Dimming
○Pin 9: 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)
RRT
15000
fSW [kHz]
[k]
The oscillation setting ranges from 50kHz to 1000kHz.
The setting example is separately described in the section ”3.2.4 DCDC Oscillation Frequency Setting”.
○Pin 10: 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 (MS).
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 4096clk (212clk), IC will be
latched off. (Please refer to section “3.5.6 Timing Chart”.)
The loop compensation setting is described in section "3.4 Loop Compensation".
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○Pin 11: ISENSE
This is the input terminal for the current detection. Error amplifier will be 3
Dimming modes by the voltage input from the MS voltage. The 3 modes are
compared with each DET voltage. And it detects abnormal LED overcurrent at
ISENSE=3.0V(typ) over. If GATE terminal continues during four CLKs
(equivalent to 40us at fosc = 100kHz), it becomes latch-off.
(Please refer to section “3.5.7 Timing Chart”.)
Vout
BD9409
ISENSE
Detect level[V]
DIMOUT
Error AMP
0.500V
ISENSE
-
0.455V
+
Rs
0.341V
CS DET
Level
Selecter
MS
FB
0
0 0.25V
0.70V
1.25V
1.70V
2.25V
2.70V
10V
MS[V]
Figure 10. Relationship of the feedback voltage and MS
Figure 11. ISENSE terminal circuit example
○Pin 12: GND
This is the GND pin of the IC.
Vout
○Pin 13: 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
“3.5 Timing Chart” 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.
Status
DIMOUT output
Normal
Same logic to PWM
Abnormal
GND Level
REG90
DIMOUT
RDIM
ISENSE
BD9409
Figure 12. DIMOUT terminal circuit
example
○Pin 14: 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 15: 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.
BD9409
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 next
CS
boost pulse will be restarted to normal frequency.
Cs
In addition, the CS voltage is more than 1.0V(typ.) during four GATE clocks, IC will
Rcs
be latch off. As above OCP operation, if the current continues to flow nevertheless
GND
GATE=L because of the destruction of the boost MOS, IC will stops the operation
completely.
Figure 13. 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 section “3.3.1 OCP Setting / Calculation Method for the Current Rating of DCDC Parts”, for detailed
explanation.
If the capacitance Cs 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
Cs, as the CS pin voltage moves according to Id.
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BD9409F
○Pin 16: 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 11.5V for stable 9V
output.
Please place the ceramic capacitor connected to REG90 pin
(1.0μF to 10μF) closest to REG90-GND pin.
10
REG90[V]
8
6
4
2
0
0
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5
10
15
20
25
30
VCC[V]
Figure 14. REG90 line regulation
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35
BD9409F
2.6 List of The Protection Function Detection Condition (Typ Condition)
Detect condition
Protect
Detection
pin
function
Detection condition
PWM
SS
Release
condition
Timer
operation
Protection type
Auto-restart after detection
(Judge periodically
whether normal or not)
Auto-restart after detection
(Judge periodically
whether normal or not)
FBMAX
FB
FB > 4.0V
H(4clk)
SS>3.7V
FB < 4.0V
212clk
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
VCC UVLO
VCC
VCC10.5V
NO
OVP
OVP
OVP>3.0V
-
-
OVP0.4V
-
-
-
NO
Pulse by pulse
4clk
Auto-restart after detection
(Judge periodically
whether normal or not)
OCP LATCH
CS
CS>1.0V
-
-
CS4.0V(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 4096clk (212clk), IC will be latched off. The latch off
interval can be calculated by the external resistor of RT pin. (Please refer to the section 3.2.7.)
(*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 section 3.2.7.)
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3.5.7 LED OCP Detection
STB
MS
PWM
REG90
AUTO COUNTER
131072 count
SS
Less than
4count
3.0V
RESET
START
3.0V
END
4count
START
Less than
4count
3.0V
END
3.0V
START
START
Abnormal
COUNTER
3.0V
RESET
3.0V
ISENSE
0.4V
GATE
DIMOUT
FAIL
STATE NORMAL
LEDOCP
NORMAL
abnormal
(*1)
(*2)
Latch off and
AUTO COUNTER
LEDOCP
NORMAL
NORMAL
abnormal
abnormal
(*3)
LEDOCP
(*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 will be latched off. After latched off, auto counter
starts counting.
(*5)…Once IC is latched off, 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 section 3.2.7.)
(*7)…The operation of the LEDOCP detection is not related to the logic of the PWM.
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3.6
I/O Equivalent Circuits
OVP
100k
UVLO
OVP
50k
SS
UVLO
SS
3k
5V
5V
5V
RT
PWM
RT
FAIL
PWM
100k
VCC
FAIL
3k
5V
1M
MS
FB
DIMOUT / REG90
REG90
20k
MS
DIMOUT
FB
5V
100k
GATE / REG90 / CS
STB
GND
ISENSE
REG90
GATE
200k
100k
STB
ISENSE
5V
5V
GND
20k
1M
CS
Figure 37. I/O Equivalent Circuits
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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.
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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
Parasitic
Elements
N
P+
N P
N
P+
B
N
C
E
Parasitic
Elements
P Substrate
P Substrate
Parasitic
Elements
Pin B
B
GND
Parasitic
Elements
GND
GND
N Region
close-by
GND
Figure 38. 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.
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Ordering Information
B
D
9
4
0
Part Number
9
F
-
Package
F:SOP16
E2
Packaging and forming specification
E2: Embossed tape and reel
Marking Diagrams
SOP16(TOP VIEW)
Part Number Marking
BD9409F
LOT Number
1PIN MARK
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Physical Dimension, Tape and Reel Information
Package Name
SOP16
(Max 10.35 (include.BURR))
(UNIT : mm)
PKG : SOP16
Drawing No. : EX114-5001
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Revision History
Date
Revision
01 Nov 2016
Rev.001
Changes
New Release
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Notice
Precaution on using ROHM Products
1.
Our Products are designed and manufactured for application in ordinary electronic equipments (such as AV equipment,
OA equipment, telecommunication equipment, home electronic appliances, amusement equipment, etc.). If you
(Note 1)
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
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Rev.001
