LED Driver series for lighting
Step-down type
with 1.5A output
No.09093EAT01
BD9207FPS
●Description
BD9207FPS is a LED driver with built-in step-down switching regulator and incorporates the built-in switching MOS EFT of
Pch.
Feedback voltage is as low as 0.2V and can suppress the loss on the sense resistance of LED.
It is operated by PWM method with an oscillating frequency of 900 KHz and can use smaller coil than a switching regulator
of low-frequency operation.
●Features
1) Maximum switching current of 1.5A
2) Built-in Pch switching MOS FET for high efficiency
3) Low loss because feedback voltage is as low as 0.2V
4) High oscillating frequency of 900KHz (Fixed)
5) Built-in soft start function
6) Built-in overcurrent protection circuit (OCP)
7) Built-in thermal shutdown circuit (TSD)
8) ON/OFF of output is possible by STBY terminal.
9) Compact surface-mount TO252S-5 package
●Applications
・For use in the light sources of PPC
・Printer etc. and the LCD backlights of LED lighting apparatus & monitor
・Note PC etc.
●Absolute maximum ratings(Ta=25℃)
Parameter
Symbol
Rating
Unit
Vcc
36
V
STBY-GND Voltage
VSTBY
36
V
OUT-GND Voltage
VOUT
36
V
INV-GND Voltage
VINV
5
V
Maximum switching output current.
Iout
1.5(*1)
A
Allowable loss
Pd
800(*2)
mW
Supply voltage(VCC-GND)
Operating temperature range
Topr
-20 ~ +85
℃
Storage temperature range
Tstg
-55 ~ +150
℃
(*1)Regardless of the listed rating, do not exceeded Pd, ASO or Tjmax=150℃.
(*2) Without heat sink, reducing by the 16 mW every 1℃ rise in temperature. (above 25℃)
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1/11
2009.07 - Rev.A
Technical Note
BD9207FPS
●Operating range (Ta=-40~+85℃)
Limit
Parameter
Symbol
Supply voltage
VCC
Output voltage
Vo
Unit
Min.
Typ.
Max.
8.0
-
35.0
V
-
0.8×
(VCC-Io×Ron)
V
2.5
Conditions
●Electrical characteristics(Unless otherwise specified, Ta=25℃,VCC=24V,STBY=3V)
Parameter
Symbol
Min.
Limit
Typ.
Max.
Unit
Output MOS ON resistance
Ron
-
1.0
1.5
Ω
Oscillating frequency
fosc
810
900
990
kHz
Overcurrent detection current
Iocp
1.6
-
-
A
INV terminal threshold
voltage
VINV
0.194
0.200
0.206
V
INV terminal bypass current
IINV
-
1
2
μA
VSTBYON
VSTBYOFF
2.0
-0.3
-
36
0.3
V
V
Istby
5
15
30
μA
Circuit current
Icc
-
5
12
mA
Standby current
Ist
-
0
5
μA
Soft start time
Tss
-
-
10
ms
STBY terminal control
voltage
ON
OFF
STBY terminal inflow current
Conditions
VINV=0.2V
STBY=3V
STBY=0V
STBY=0→3V
Without radiation-proof design.
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© 2009 ROHM Co., Ltd. All rights reserved.
2/11
2009.07 - Rev.A
Technical Note
BD9207FPS
●Block diagram
VCC
1
VREF
PWM COMP
DRIVER
OSC
STBY
5
STBY
CTL
LOGIC
OUT
2
OCP
TSD
INV
Error AMP
4
SS
FIN
GND
●Outline drawing of package
●Explanation of terminal
Pin No.
Pin Name
Function
1
VCC
2
OUT
3※
OUT
Drain terminal of
built-in PMOS FET
FIN
GND
Ground terminal
4
INV
Output voltage
feedback
terminal
5
STBY
ON/OFF control
terminal
Supply voltage
terminal
Drain terminal of
built-in PMOS FET
※Used normally in open-circuit condition
TO252S-5(Unit:mm)
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© 2009 ROHM Co., Ltd. All rights reserved.
3/11
2009.07 - Rev.A
Technical Note
BD9207FPS
●Functional explanation of block
・
VREF
The constant voltage to be temperature-compensated is created from the voltage inputted from VCC terminal.
・
OSC
Triangular wave with an oscillating frequency of 900 KHz is created, as an input of PWM comparator, by built-in resistor
and capacitor.
・
Error AMP
It detects, at INC terminal, the voltage of sense resistance terminal created by LEC current, and compares it to the
reference voltage, and amplifies and outputs the differential voltage.
(The reference voltage is 0.2V±3%)
・
PWM COMP
PWM COMP converts the output voltage of error amplifier into the pulse-width modulation waveform and outputs it to
DRIVER.
・
DRIVER
Push-pull FET driver takes in the PWM waveform and directly drives the Pch MOS FET that is built-in in the IC.
・
STBY
The ON/OFF control of output is performed by STBY terminal. The output becomes ON if STBY voltage is High level.
・
Thermal shutdown circuit (TSD)
TSD circuit protects the IC from runaway thermal operation or heat damage.
TSD circuit detects the temperature of chip, and the circuit becomes off if the temperature reaches 175℃. For TSD
detection and release, the hysteresis of 15℃ is set, so the malfunction caused by temperature variation is prevented.
・
Over Current Protection(OCP)
Out is turned off if the voltage difference between VCC – OUT, caused by the current flowing in the Pch MOS EFT built-in
in OCP circuit, is detected and reaches the reference value of OCP. The OCP is not of latch type but of self-return type.
・
Soft start circuit (SS)
Soft start time is set by the built-in capacitor connected to SS circuit. The capacitor is charged when STBY terminal
becomes High level and the IC is started. The soft start time is set at 4ms or so.
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4/11
2009.07 - Rev.A
Technical Note
BD9207FPS
●Selection and setting of application parts
Coil L1
The application efficiency will decrease by the larger serial resistance element of coil. Moreover, because OCP operates
by 1.6A(min) or more, so please notice the heat generated by overload output or short.
Please set current ratings of coil with IOUT(MAX)+⊿IL or more. Iout(MAX): maximum load current
If current flows more than ratings current, then coil generates heat, magnetic saturation, and causes oscillation or low
efficiency.
Please select the peak current with enough margins not to exceed current rating of coil.
⊿IL. =
(VCC-VOUT)
L1
×
VOUT
VCC
×
1
fosc
L1: Coil value,VCC: Input voltage,VOUT: Output voltage, ⊿IL: Ripple current, fosc: Oscillation frequency
When value the efficiency , we recommend C10-H5R(mitsumi) . Efficiency will be improved about 1~2%.
Schottky diode D1
Please select Schottky diode with lowest forward voltage VF.
(We can suppress the dissipation of forward voltage descent, and raise the efficiency. )
Diode selection is based on maximum forward current rating, reverse voltage rating and permissible power dissipation of
diode.
・The maximum current ratings are assumed more than the value of maximum load current+ coil ripple current(⊿IL).
・Reverse voltage rating is set to be VIN or more.
・Please choose the smallest one of reverse current IR.
Especially, IR grows at high temperature, and causes thermo runaway.
・Select the diode which permissible power dissipation within ratings.
Diode power dissipation Pdi is shown below.
Pdi=Iout(MAX)×Vf×(1-VOUT/VCC)
Iout(MAX): Load current. Vf: Forward voltage, VOUT: Output voltage, VCC: Input voltage
Output capacitor
C1
Select the output capacitor with ESR met the following formula.
ESR≦⊿VL/⊿IL
⊿VL : Permissible ripple voltage, ⊿IL : Ripple current
Moreover, permissible ripple current effective value of output capacity is calculated by the next formula, and use this
value to select the capacitor with enough margins.
IRMS =⊿IL/2√3
IRMS: Permissible ripple current effective value of output capacity, ⊿IL : Ripple current
Ceramic capacitor must use the one more than B characteristic.
Besides above mentioned, IC might not be normally operated according to the different setting condition of ambient
temperature and output voltage.
Moreover, even aluminum electrolytic capacitor can be used, please confirm its operation enough before using it.
Input capacitor C2
Input capacitor built in Pch MOS FET ON is the current supply of coil by FET.
So, please close to IC as near as possible to connect it. Enough margins is taken on setting input capacitor in capacitor
withstand voltage and permissible ripple current value. According to the ripple current effective value of input capacitor
shown below, select the capacitor with enough permissible ripple current value.
IRMS=IOUT×√ (1-VOUT / VCC)×VOUT / VCC
IRMS : Permissible ripple current value of input capacitor
IOUT : Load current. VOUT: Output voltage, VCC: Input voltage
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5/11
2009.07 - Rev.A
Technical Note
BD9207FPS
Resistance R1
LED Current value is set below according to sense resistance R1.
ILED[A]=VINV[V]/R1[Ω]
=0.2V/R1[Ω]
Moreover, DCDC Output voltage will be the value below.
VO[V]=VF(LED Forward voltage)+VINV[V]
=VF+0.2V(typ)
● Recommended circuit example and notes of substrate layout
・
・
To prevent noise and low efficiency, please set up the capacitor and Schottky diode between VCC – GND as near as
possible to IC.
Please connect the resistance and output LC filter capacitor between INV – GND with same GND for the stability of
output voltage.
Coil
L1=10μH
Diode
D1
Capacitor
C1=10μF(25V)
C2=4.7μF(50V)
Resistance
R1=0.43Ω
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© 2009 ROHM Co., Ltd. All rights reserved.
:C6-K3LA(mitsumi)
:RB050LA-30(ROHM)
:Ceramic capacitor GRM31CB31E106KA75L(murata)
:Ceramic capacitor
GRM32EB31H475KA87L(murata)
:MCR10EZPFR430(ROHM)
6/11
2009.07 - Rev.A
Technical Note
BD9207FPS
● Measurement circuit diagram
Vcc
OUT
1
2
cccc
+
GND
INV
STBY
4
5
FIN
SW2
Icc A
SW4
0.43Ω
Vcc
SW5
A IINV
A ISTB
VINV
VSTB
+
f
SW6
V
Vo
Io
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7/11
2009.07 - Rev.A
Technical Note
BD9207FPS
● Heat transfer characteristic
①IC unit
②2 layers substrate(area of substrate back copper foil:15 mm×15mm)
③2 layers substrate(area of substrate back copper foil:70 mm×70mm)
(W)
5
POWER DISSIPATION [Pd]
4
③3.50W
3
②1.85W
2
①0.80W
1
0
0
25
75 85
50
100
125
AMBIENT TEMPERATURE [Ta]
150
(℃)
● I/O terminal equivalent circuit diagram
1Pin,FIN (VCC, GND)
2pin (OUT)
4pin (INV)
5pin (STBY)
VCC
VCC
VCC
STBY
VCC
INV
OUT
GND
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© 2009 ROHM Co., Ltd. All rights reserved.
8/11
2009.07 - Rev.A
Technical Note
BD9207FPS
●Notes for use
1.
We have paid enough attention to quality control of this product, but it may be destroyed when the absolute
maximum rating of impressed voltage and operating temperature range is exceeded. Because we can’t specify
that is short-mode or open-mode etc while it is destroyed, so please discuss to give physical safety action with
postulating the special mode exceeded absolute maximum rating.
2.
About application circuit
Application circuit is recommended, but please fully confirm temperature characteristic etc when using it. Moreover,
please acknowledge that our company can’t confirm enough about patent.
3.
About the range of operation power-supply voltage
Circuit function operation at the range of operation ambient temperature is guaranteed when it is in the range of
operation power-supply voltage. About characteristic value, the specification value of electric characteristic can’t
be guaranteed, but the characteristic value doesn’t change rapidly in these ranges.
4.
About ground connection
The ground connection shown in application circuit example should equip enough fat GND(FIN) to every ground
connection with shortest pattern drawing, and the pattern shouldn’t interfere the electric characteristic.
5.
About input power-supply
The input power-supply shown in application circuit example should equip input pin VCC(1pin) with short enough
pattern drawing, and the pattern shouldn’t interfere the electric characteristic.
6.
Please think about permissible power dissipation (Pd) in an actual using status, and do the heat design with
enough margins.
7.
Please pay enough attention to the direction and displacement of IC when you install it on PCB. If you install it by
mistake, IC might be destroyed, Moreover, when short-circuit happen by foreign substance entered between
outputs, or output and power supply GND, it will be destroyed.
8.
Please note that there is a possibility of malfunction if you use it in strong electromagnetic field.
9.
Please set STBY terminal voltage to 0.3V or less when putting it on standby status, to 2.0V or more when putting it
on operation status.
Please do not fix STBY terminal voltage from 0.3V to 2.0V. It may cause malfunction or breakdown.
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9/11
2009.07 - Rev.A
Technical Note
BD9207FPS
10. This IC is a monolithic IC, and there are P + isolation and P substrate for element separation between each
element. P-N joint is formed with this P layer and N each element’s layer, and various parasitic elements are
composed.
For instance, as shown in the figure below, when resistance and transistor are connected with terminal:
○ P-N joint operates as a parasitic diode when GND > (terminal A) in resistance, GND >(terminal B) in transistor
(NPN).
○ Moreover, when GND > (terminal B) in transistor (NPN),the parasitic NPN transistor operates with N layer of other
elements adjoining with above-mentioned parasitic diode.
According to potential relation, parasitic element in IC structure can be consequent. The operating of parasitic
element maybe interfere the circuit operation, and become the cause of malfunction and destruction. Therefore,
please pay enough attention not to use it by impressing lower voltage than GND (P substrate) on I/O terminal etc
to operate parasitic element.
Resistance
Transistor(NPN)
B
E
~
~
C
(TerminalB)
~
~
(TerminalA)
GND
N
P
+
P
P
+
P
+
P
P+
N
N
N
N
N
N
Parasitic element
Psubstrate
Psubstrate
GND
GND
Parasitic element
(TerminalB)
C
~
~
(TerminalA)
B
GND
~
~
Parasitic element
E
GND
other adjoining elements
Parasitic element
Simple structure example of bipolar IC
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10/11
2009.07 - Rev.A
Technical Note
BD9207FPS
●Ordering part number
B
D
9
Part No.
2
0
7
F
Part No.
P
S
Package
FPS: TO252S-5
-
E
2
Packaging and forming specification
E2: Embossed tape and reel
TO252S-5
+0.2
5.1−0.1
1.5±0.2
1.2±0.1
0.27±0.1
6.5±0.2
C0.5
Tape
Embossed carrier tape
Quantity
2000pcs
Direction
of feed
E2
The direction is the 1pin of product is at the lower left when you hold
( reel on the left hand and you pull out the tape on the right hand
)
0.8
3
9.5±0.3
1.0±0.2
2.5±0.15
5.5±0.2
FIN
0.71
1
2
4
5
4 +6
–4
0.27±0.1
0.35±0.1
S
1.27
0.27±0.1
0.08 S
0.08
0.6±0.2
M
1pin
(Unit : mm)
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© 2009 ROHM Co., Ltd. All rights reserved.
Reel
11/11
Direction of feed
∗ Order quantity needs to be multiple of the minimum quantity.
2009.07 - Rev.A
Datasheet
Notice
Precaution on using ROHM Products
1.
Our Products are designed and manufactured for application in ordinary electronic equipments (such as AV equipment,
OA equipment, telecommunication equipment, home electronic appliances, amusement equipment, etc.). If you
(Note 1)
, transport
intend to use our Products in devices requiring extremely high reliability (such as medical equipment
equipment, traffic equipment, aircraft/spacecraft, nuclear power controllers, fuel controllers, car equipment including car
accessories, safety devices, etc.) and whose malfunction or failure may cause loss of human life, bodily injury or
serious damage to property (“Specific Applications”), please consult with the ROHM sales representative in advance.
Unless otherwise agreed in writing by ROHM in advance, ROHM shall not be in any way responsible or liable for any
damages, expenses or losses incurred by you or third parties arising from the use of any ROHM’s Products for Specific
Applications.
(Note1) Medical Equipment Classification of the Specific Applications
JAPAN
USA
EU
CHINA
CLASSⅢ
CLASSⅡb
CLASSⅢ
CLASSⅢ
CLASSⅣ
CLASSⅢ
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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
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responsible or liable for any damages, expenses or losses arising from the use of any ROHM’s Products under any
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extraordinary environments or conditions (as exemplified below), your independent verification and confirmation of
product performance, reliability, etc, prior to use, must be necessary:
[a] Use of our Products in any types of liquid, including water, oils, chemicals, and organic solvents
[b] Use of our Products outdoors or in places where the Products are exposed to direct sunlight or dust
[c] Use of our Products in places where the Products are exposed to sea wind or corrosive gases, including Cl2,
H2S, NH3, SO2, and NO2
[d] Use of our Products in places where the Products are exposed to static electricity or electromagnetic waves
[e] Use of our Products in proximity to heat-producing components, plastic cords, or other flammable items
[f] Sealing or coating our Products with resin or other coating materials
[g] Use of our Products without cleaning residue of flux (even if you use no-clean type fluxes, cleaning residue of
flux is recommended); or Washing our Products by using water or water-soluble cleaning agents for cleaning
residue after soldering
[h] Use of the Products in places subject to dew condensation
4.
The Products are not subject to radiation-proof design.
5.
Please verify and confirm characteristics of the final or mounted products in using the Products.
6.
In particular, if a transient load (a large amount of load applied in a short period of time, such as pulse. is applied,
confirmation of performance characteristics after on-board mounting is strongly recommended. Avoid applying power
exceeding normal rated power; exceeding the power rating under steady-state loading condition may negatively affect
product performance and reliability.
7.
De-rate Power Dissipation (Pd) depending on Ambient temperature (Ta). When used in sealed area, confirm the actual
ambient temperature.
8.
Confirm that operation temperature is within the specified range described in the product specification.
9.
ROHM shall not be in any way responsible or liable for failure induced under deviant condition from what is defined in
this document.
Precaution for Mounting / Circuit board design
1.
When a highly active halogenous (chlorine, bromine, etc.) flux is used, the residue of flux may negatively affect product
performance and reliability.
2.
In principle, the reflow soldering method must be used; if flow soldering method is preferred, please consult with the
ROHM representative in advance.
For details, please refer to ROHM Mounting specification
Notice - GE
© 2014 ROHM Co., Ltd. All rights reserved.
Rev.002
Datasheet
Precautions Regarding Application Examples and External Circuits
1.
If change is made to the constant of an external circuit, please allow a sufficient margin considering variations of the
characteristics of the Products and external components, including transient characteristics, as well as static
characteristics.
2.
You agree that application notes, reference designs, and associated data and information contained in this document
are presented only as guidance for Products use. Therefore, in case you use such information, you are solely
responsible for it and you must exercise your own independent verification and judgment in the use of such information
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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.
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3.
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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.
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© 2014 ROHM Co., Ltd. All rights reserved.
Rev.002
Datasheet
General Precaution
1. Before you use our Pro ducts, you are requested to care fully read this document and fully understand its contents.
ROHM shall n ot be in an y way responsible or liabl e for fa ilure, malfunction or acci dent arising from the use of a ny
ROHM’s Products against warning, caution or note contained in this document.
2. All information contained in this docume nt is current as of the issuing date and subj ect to change without any prior
notice. Before purchasing or using ROHM’s Products, please confirm the la test information with a ROHM sale s
representative.
3.
The information contained in this doc ument is provi ded on an “as is” basis and ROHM does not warrant that all
information contained in this document is accurate an d/or error-free. ROHM shall not be in an y way responsible or
liable for an y damages, expenses or losses incurred b y you or third parties resulting from inaccur acy or errors of or
concerning such information.
Notice – WE
© 2014 ROHM Co., Ltd. All rights reserved.
Rev.001