BCR402U_09

BCR402U LED Driver Features • LED drive current of 20mA • Output current adjustable up to 65mA with external resistor • Supply voltage up to 40V • Easy paralleling of drivers to increase current • 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 BCR402U 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 BCR402U 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 BCR402U 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 5 6 1 4 2 3 BCR402U Pin Configuration Typical Application BCR402U GND 1 6 Rext +Vs B C R 402U 4 R ext (o p tio n a l) V d ro p 6 Out 2 5 Out Out 3 4 Vs 1 Is 2 ,3 ,5 Io u t Type BCR402U Maximum Ratings Parameter Supply voltage Output current Output voltage Marking L2s 1 = GND Pin Configuration 2;3;5 = Out 4 = VS 6 = R ext Package SC74 Symbol Value 40 65 38 0.5 750 150 -65 ... 150 Unit V mA V mW °C VS Iout Vout VR Ptot Tj Tstg Reverse voltage between all terminals Total power dissipation, TS = 125 °C Junction temperature Storage temperature Thermal Resistance Parameter Junction - soldering point1) Symbol Value 50 Unit K/W RthJS 1For calculation of R thJA please refer to Application Note Thermal Resistance 2 2009-07-31 BCR402U Electrical Characteristics at TA=25°C, unless otherwise specified Parameter Characteristics Collector-emitter breakdown voltage Symbol min. Values typ. 420 220 44 20 0.85 max. 500 470 53 22 0.9 V µA Ω mA V Unit VBR(CEO) IS hFE Rint Iout Vdrop 40 340 100 37 18 0.8 IC = 1 mA, I B = 0 Supply current VS = 1 0 V DC current gain IC = 50 mA, VCE = 1 V Internal resistor IRint = 20 mA Output current VS = 10 V, Vout = 8.6 V Voltage drop (VS - VE) IC = 20 mA DC Characteristics with stabilized LED load Lowest sufficient battery voltage overhead VSmin ∆Iout/Iout ∆Iout/Iout - 1.4 -0.2 1 - V %/K %/V Iout > 18mA Output current change versus T A VS = 10 V Output current change versus VS VS = 10 V 3 2009-07-31 BCR402U Total power dissipation Ptot = f (TS) Permissible Pulse Load RthJS = f (tp) 1000 mW 10 2 K/W 800 700 10 1 600 500 400 RthJS P tot 10 300 200 100 0 0 0 0.5 0.2 0.1 0.05 0.02 0.01 0.005 D=0 10 -6 20 40 60 80 100 120 °C 150 10 -1 -7 10 10 -5 10 -4 10 -3 10 -2 s 10 0 TS tp Permissible Pulse Load Ptotmax / PtotDC = f (tp) 10 3 P totmax / P totDC - 10 2 D=0 0.005 0.01 0.02 0.05 0.1 0.2 0.5 10 1 10 0 - 7 10 10 -6 10 -5 10 -4 10 -3 10 -2 s 10 0 tp 4 2009-07-31 BCR402U Output current versus supply voltage Supply current versus supply voltage Iout = f (V S); R ext = Parameter VS - Vout = 1.4 V 10 -1 IS = f(VS) TA = Parameter 0.002 A A 0.0016 0.0014 80°C 20°C -40°C Iout 10 - 2 Rext = 24 Ohm Rext = 75 Ohm Rext = open IS 0.0012 0.001 0.0008 0.0006 0.0004 0.0002 10 -3 0 5 10 15 V 25 0 0 5 10 15 20 25 30 35 40 V VS 50 VS Output current versus supply voltage Output current versus supply voltage Iout = ƒ(VS), TA = 20°C VS -Vout as Parameter 10 - 1 Iout = ƒ(VS), VS -Vout = 1.4 V TA = Parameter 0.025 -40°C A 20°C 80°C Iout Iout A 1.2V-2V 1V 0.015 0.01 0.005 10 -2 0 5 10 15 20 25 30 35 40 V 50 0 0 5 10 15 20 25 30 35 40 V 50 VS VS 5 2009-07-31 BCR402U Output current versus external resistor Output current Iout = (Rext), VS = 10V, VS -Vout = 1.4 V TA = Parameter 10 -1 Iout (TS), VS = 10V, VS -Vout = 1.4 V REXT = Parameter 70 mA 18 Ohm 27 Ohm 50 33 Ohm Iout A 80°C 20°C -40°C Iout 40 56 Ohm 30 120 Ohm 20 open 10 10 -2 1 10 OHM Rext 10 2 0 -50 -25 0 25 50 75 100 °C 150 TS Reference Voltage (Vdrop) versus Iout = 10 µA ... 10 mA Reference Voltage (Vdrop) versus Iout = 10 mA ... 65 mA 6 2009-07-31 BCR402U Application circuit: Stand alone current source Application circuit: Boost mode current source with external power transistor +Vs B C R 4 0 2U 4 R e xt (o ption al) V drop +Vs B C R 4 0 2U 4 R e xt (o ption al) V dro p 6 6 I LE D 1 Is 2 ,3,5 Io u t 1 Is 2 ,3,5 Io u t R1 R2 Application hints BCR402U 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 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 BCR402U Package Outline 2.9 ±0.2 (2.25) B (0.35) 2.5 ±0.1 6 5 4 1.1 MAX. 0.15 +0.1 -0.06 0.25 ±0.1 1.6 ±0.1 10˚ MAX. 1 2 3 Pin 1 marking 1.9 0.35 +0.1 -0.05 0.95 10˚ MAX. 0.2 M B 6x 0.2 M A 0.1 MAX. A Foot Print 0.5 0.95 Marking Layout (Example) Small variations in positioning of Date code, Type code and Manufacture are possible. 1.9 2.9 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. 4 0.2 Pin 1 marking 3.15 2.7 8 1.15 8 2009-07-31 BCR402U 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