2009-11-13
1
BCR402R
LED Driver
Features
• LED drive current of 20mA
• Output current adjustable up to 60mA with
external resistor
• Supply voltage up to 18V
• Easy paralleling of drivers to increase current
• Low voltage overhead of 1.2V
• High current accuracy at supply voltage variation
• No EMI
• Reduced output current at higher temperatures - negative thermal coefficient of -0.3% / K
• RoHS compliant (pb-free) SOT143R package
• Qualified according AEC Q101
Applications
• Channel letters for advertising, LED strips for decorative lighting
• Aircraft, tra in, ship illumination
• Retrofits for general lighting, white goods like refrigerator lighting
• Medical ligh ting
1
2
4
3
General Description
The BCR402R is a cost efficient LED driver to drive low power LED’s. The advantages
towards resistor biasing are:
• homogenous light output despite varying forward voltages in different LED strings
• homogenous light output of LED’s despite voltage drop across long supply lines
• homogenous light output independent from supply voltage variations
• longer lifetime of the LED’s due to reduced output current at higher temperatures
(negative thermal coefficient)
The advantages towards discrete solutions are:
• lower assembly cost
• smaller form factor
• better quality due to less soldering points
• higher output current accuracy due to pretested LED drivers
Dimming is possible by using an external digital transistor at the ground pin.
The BCR402R can be operated at higher supply voltages by putting LED’s between the
power supply +VS and the power supply pin of the LED driver. You can find further details
in the application note AN066.
The BCR402R is a perfect fit for numerous low power LED applications by combining small
form factor with low cost. These LED drivers offer several advantages to resistors like
significantly higher current control at very low voltage drop ensuring high lifetime of LED’s.
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BCR402R
Typical ApplicationPin Configuration
BCR 402R
Vdrop
Rext
3
4
2
1
+Vs
Is Iout
EHA07188
4 3
21
Type Marking Pin Configuration Package
BCR402R W6s 1 = G ND 2 =
I
out 3 =
V
S4 =
R
ext SOT143R
Maximum Ratings
Parameter Symbol Value Unit
Supply voltage
V
S18 V
Output current
I
out 60 mA
Output voltage
V
out 16 V
Reverse voltage between all terminals
V
R0.5
Total power dissipation,
T
S ≤ 75 °C
P
tot 330 mW
Junction temperature
T
j150 °C
Storage temperature
T
stg -65 ... 150
Thermal Resistance
Parameter Symbol Value Unit
Junction - soldering point1)
R
thJS 225 K/W
1For calculation of
R
thJA please refer to Application Note Thermal Resistance
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BCR402R
Electrical Characteristics at
T
A=25°C, unless otherwise specified
Parameter Symbol Values Unit
min. typ. max.
Characteristics
Collector-emitter breakdown voltage
I
C = 100 µA,
I
B = 0
V
BR(CEO) 18 - - -
Supply current
V
S = 10 V
I
S350 440 540 µA
DC current gain
I
C = 50 mA,
V
CE = 1 V
h
FE -150 - -
Internal resistor
I
Rint = 10 mA
R
int 33 38 47 Ω
Output current
V
S = 10 V,
V
out = 7.6 V
I
out 18 20 22 mA
Voltage drop (
V
S -
V
E)
Iout = 20 mA
V
drop -0.76 - V
DC Characteristics with stabilized LED load
Lowest sufficient supply voltage overhead
I
out > 8mA
V
Smin -1.2 - V
Output current change versus
T
A
V
S = 10 V ∆
I
out/
I
out --0.3 -%/K
Output current change versus
V
S
V
S = 10 V ∆
I
out/
I
out - 2 - %/V
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BCR402R
Total power dissipation
P
tot =
f
(
T
S)
015 30 45 60 75 90 105 120 °C 150
T
S
0
30
60
90
120
150
180
210
240
270
300
mA
360
P
tot
Permissible Pulse Load
R
thJS =
f
(
t
p)
10 -7 10 -6 10 -5 10 -4 10 -3 10 -2 10 0
s
t
p
0
10
1
10
2
10
3
10
K/W
R
thJS
0.5
0.2
0.1
0.05
0.02
0.01
0.005
D = 0
Permissible Pulse Load
P
totmax /
P
totDC =
f
(
t
p)
10 -7 10 -6 10 -5 10 -4 10 -3 10 -2 10 0
s
t
p
0
10
1
10
2
10
-
P
totmax/
P
totDC
D = 0
0.005
0.01
0.02
0.05
0.1
0.2
0.5
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BCR402R
Supply current versus supply voltage
I
S =
f
(
V
S)
Load: two LEDs with
V
F = 3.8V in series
0 2 4 6 8 10 12 14 16 V20
V
S
-5
10
-4
10
-3
10
A
I
S
Output current versus supply voltage
I
out =
f
(
V
S);
R
ext = Parameter
Load: two LEDs with
V
F = 3.8V in series
0 2 4 6 8 10 12 14 16 V20
V
S
-3
10
-2
10
-1
10
A
I
out
Rext = open
Rext = 68 Ohm
Output current versus reference voltage
I
out =
f
(
V
DROP);
V
S = 10V;
V
out = 7.6V
0.6 0.65 0.7 0.75 0.8 0.85 0.9 V1
V
drop
-5
10
-4
10
-3
10
-2
10
-1
10
A
I
out
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BCR402R
Application Circuit:
supply voltages >18V
Standard Application Circuit:
BCR 402R
Vdrop
Rext
3
4
2
1
+Vs
Is Iout
Rsense
(optional)
Vsupply
BCR401R
BCR402R
LEDs
Vs
GND
Rext
Iout
LEDs
IOUT
IOUT + IDRIVER
IDRIVER
Application hints
BCR402R serves as an easy to use constant current source for LEDs. In stand alone
application an external resistor can be connected to adjust the current from 20 mA to 60 mA.
Rext can be determined by using the diagram 'Output current versus external resistor',
or by refering to diagram 'Output current versus reference voltage'. Look for your desired
output current on the y axis and read out the corresponding Vdrop. Calculate Rext:
Rext = Vdrop / (Iout -(Vdrop/Rint))
Please take into account that the resulting output currents will be slightly lower due to the
self heating of the component and the negative thermal coefficient.
Please visit our web site for application notes: www.infineon.com/lowcostleddriver
• AN066 explains the basic concept
• AN077 gives hints to thermal design
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BCR402R
Package SOT143R
1.1
0.8 0.81.2
0.90.9
0.8 0.8 1.2
Package Outline
Foot Print
Marking Layout (Example)
Standard Packing
Reel ø180 mm = 3.000 Pieces/Reel
Reel ø330 mm = 10.000 Pieces/Reel
2.6
4
3.15
Pin 1
8
0.2
1.15
Reverse bar
2005, June
Date code (YM)
BFP181R
Type code
Pin 1
1.9
1.7
0.4
-0.05
+0.1
+0.1
-0.05
0.8
B
0.25
M
B
2.9
±0.1
0.2
12
43
A
0˚... 8˚
10˚
10˚
0.1 MAX.
0.15 MIN.
1.3
±0.1
2.4
±0.15
1
±0.1
0.08...0.15
A
M
0.2
MAX.
MAX.
Manufacturer
2009-11-13
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BCR402R
Published by
Infineon Technologies AG
81726 München, Germany
© Infineon Technologies AG 2007.
All Rights Reserved.
Attention please!
The information given in this data sheet shall in no event be regarded as a guarantee
of conditions or characteristics (“Beschaffenheitsgarantie”). With respect to any
examples or hints given herein, any typical values stated herein and/or any information
regarding the application of the device, Infineon Technologies hereby disclaims any
and all warranties and liabilities of any kind, including without limitation warranties of
non-infringement of intellectual property rights of any third party.
Information
For further information on technology, delivery terms and conditions and prices
please contact your nearest Infineon Technologies Office (www.infineon.com).
Warnings
Due to technical requirements components may contain dangerous substances.
For information on the types in question please contact your nearest
Infineon Technologies Office.
Infineon Technologies Components may only be used in life-support devices or
systems with the express written approval of Infineon Technologies, if a failure of
such components can reasonably be expected to cause the failure of that
life-support device or system, or to affect the safety or effectiveness of that
device or system.
Life support devices or systems are intended to be implanted in the human body,
or to support and/or maintain and sustain and/or protect human life. If they fail,
it is reasonable to assume that the health of the user or other persons
may be endangered.
