BCR405U LED Driver Features • LED drive current of 50mA • Output current adjustable up to 65mA with external resistor 4 3 5 • Supply voltage up to 40V 2 6 • Easy paralleling of drivers to increase current 1 • Low voltage overhead of 1.4V • High current accuracy at supply voltage variation • No EMI • High power dissipation of 750mW • Reduced output current at higher temperatures - Negative thermal coefficient of -0.2% / K • RoHS compliant (pb-free) small and robust SC-74 package • Qualified according to AEC Q101 Applications • Channel letters for advertising, LED strips for decorative lighting • Aircraft, train, ship illumination • Retrofits for general lighting, white goods like refrigerator lighting • Medical lighting • Automotive applications like CHMSL and rear combination lights General Description The BCR405U 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 BCR405U 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 AN097. The BCR405U 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. 1 2009-07-31 BCR405U Pin Configuration Typical Application +Vs BCR405U GND 1 B C R 405U 6 4 Rext R ext (o p tio n a l) V d ro p 6 Out 2 5 Out Out 3 4 Vs Type BCR405U Marking L5s 1 = GND 1 Is 2 ,3 ,5 Io u t Pin Configuration 2;3;5 = Iout 4 = VS Package 6 = R ext SC74 Maximum Ratings Parameter Symbol Supply voltage VS 40 V Output current Iout 65 mA Output voltage Vout 38 V Reverse voltage between all terminals VR 0.5 Total power dissipation, TS ≤ 125 °C Ptot 750 mW Junction temperature Tj 150 °C Storage temperature Tstg Value Unit -65 ... 150 Thermal Resistance Parameter Symbol Junction - soldering point1) RthJS Value Unit 50 K/W 1For calculation of R thJA please refer to Application Note Thermal Resistance 2 2009-07-31 BCR405U Electrical Characteristics at TA=25°C, unless otherwise specified Symbol Parameter Values Unit min. typ. max. VBR(CEO) 40 - - V IS 340 420 500 µA hFE 100 220 470 - Rint 13 17 22 Ω Iout 45 50 55 mA Vdrop 0.75 0.8 0.85 V VSmin - 1.4 - V ∆Iout/Iout - -0.15 - %/K ∆Iout/Iout - 1 - %/V Characteristics Collector-emitter breakdown voltage IC = 1 mA, I B = 0 Supply current VS = 10 V DC current gain IC = 50 mA, VCE = 1 V Internal resistor IRint = 50 mA Output current VS = 10 V Voltage drop (VS - VE) Iout = 50 mA DC Characteristics with stabilized LED load Lowest sufficient battery voltage overhead Iout > 18mA Output current change versus T A VS = 10 V Output current change versus VS VS = 10 V 3 2009-07-31 BCR405U Total power dissipation Ptot = f (TS) Permissible Pulse Load RthJS = f (tp) 10 2 1000 mW K/W 800 RthJS P tot 700 600 10 1 500 400 10 0.5 0.2 0.1 0.05 0.02 0.01 0.005 D=0 0 300 200 100 0 0 20 40 60 80 100 120 °C 10 -1 -7 10 150 TS 10 -6 10 -5 10 -4 10 -3 10 -2 s 10 0 tp Permissible Pulse Load Ptotmax / PtotDC = f (tp) P totmax / P totDC 10 3 - D=0 0.005 0.01 0.02 0.05 0.1 0.2 0.5 10 2 10 1 10 0 -7 10 10 -6 10 -5 10 -4 10 -3 10 -2 s 10 0 tp 4 2009-07-31 BCR405U Output current versus supply voltage Supply current versus supply voltage Iout = f (V S); R ext = Parameter IS = f(VS) VS - Vout = 1.4 V TA = Parameter 10 -1 0.002 A 0.0016 80°C 20°C -40°C IS Iout 0.0014 56 Ohm 82 Ohm open A 0.0012 0.001 0.0008 0.0006 0.0004 0.0002 10 -2 0 5 10 15 20 25 30 35 V 0 0 45 5 10 15 20 25 30 35 40 VS V 50 VS Output current versus supply voltage Output current versus supply voltage Iout = ƒ(VS), TA = 20°C Iout = ƒ(VS), VS -Vout = 1.4 V VS -Vout as Parameter TA = Parameter 10 -1 10 -1 Iout Iout 1.2V - 2V 1V A 10 -2 0 A 5 10 15 20 25 30 35 V 10 -2 0 45 VS -40°C 20°C 80°C 5 10 15 20 25 30 35 V 45 VS 5 2009-07-31 BCR405U Output current versus external resistor Output current Iout = (Rext), VS = 10V, VS -Vout = 1.4 V TA = Parameter Iout (TS), VS = 10V, VS -Vout = 1.4 V 10 REXT = Parameter -1 70 mA 56 Ohm A open Iout Iout 50 -40°C 20°C 80°C 40 30 20 10 10 -2 1 10 10 0 -50 2 -25 0 25 50 75 Rext 100 °C 150 TS Reference Voltage (Vdrop) Reference Voltage (Vdrop) versus Iout = 10 µA ... 10 mA versus Iout = 10 mA ... 65 mA 6 2009-07-31 BCR405U Application circuit: Stand alone current source Application circuit: Boost mode current source with external power transistor +Vs B C R 4 0 5U +Vs B C R 4 0 5U 4 R e xt (o ption al) 4 R e xt (o ption al) V drop 6 V dro p 6 I LE D 1 Is 2 ,3,5 Io u t 1 Is 2 ,3,5 Io u t R1 R2 Application hints BCR405U 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 50 mA to 65 mA. Rext can be determined by using the diagram 'Output current versus external resistor', or by refering to diagram 'Reference voltage versus output current'. Look for your desired output current on the x 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. In boost mode configuration the LED current can be extended to drive high power LEDs. Select the power trasistor according the power dissipation and output current requirements. (e.g. BC817SU or BCX68-25, etc.) Dimension R2 to reduce the transistor current transfer ratio to 20 ... 50. For ILED / Iout =50 e.g. ILED= 350 mA, Iout is 7 mA. R2 = VbeON / Iout. Dimension R1 for minimum supply voltage condition: R1 = (Vsmin -1.4V -VbeON)/ Iout. Please visit our web site for application notes: www.infineon.com/lowcostleddriver • AN077 gives hints to thermal design • AN097 helps in case of high supply voltages • AN101 gives an overview to LED biasing 7 2009-07-31 SC74 Package BCR405U Package Outline B 1.1 MAX. 1 2 3 0.35 +0.1 -0.05 Pin 1 marking 0.2 B 6x M A 0.1 MAX. 0.95 0.2 1.9 1.6 ±0.1 4 10˚ MAX. 5 2.5 ±0.1 6 0.25 ±0.1 0.15 +0.1 -0.06 (0.35) 10˚ MAX. 2.9 ±0.2 (2.25) M A Foot Print 2.9 1.9 0.5 0.95 Marking Layout (Example) Small variations in positioning of Date code, Type code and Manufacture are possible. Manufacturer 2005, June Date code (Year/Month) Pin 1 marking Laser marking BCW66H Type code Standard Packing Reel ø180 mm = 3.000 Pieces/Reel Reel ø330 mm = 10.000 Pieces/Reel For symmetric types no defined Pin 1 orientation in reel. 0.2 2.7 8 4 Pin 1 marking 3.15 1.15 8 2009-07-31 BCR405U 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. 9 2009-07-31