Datasheet LED Driver for Lighting Series Electrolytic Capacitor Free Buck Converter LED Driver BD555A1AFV General Description Features BD555A1AFV is a LED driver best for LED lighting Highly efficient Buck AC/DC converter applications. It supports dimming. Constant current Primary control without feedback circuit switching controller for AC/DC buck converter is High accuracy LED current output by LED average accumulated inside. By choosing external MOS control Capacitor controller for Electrolytic free design Transistor, smalllarge power of LED can be driven. Fixed switching frequency The driver is adoptable to a wide range of lighting from Built-in regulator for inner power supply small light such as spotlights to large one like base Built-in LED open detection (shutdown type) lights. Built-in UVLO detection With digital power control, the average value of LED Built-in thermal shut-down function current is stably adjustable to requesting current. By only primary sense resistor, LED current is available to feedback LED current is useful without feedback Packages circuits, reduce parts. Input characteristics and output SSOP-B14 5.00mm6.40mm1.15mm characteristics is good by precisely digital power control. Its support electrolytic free design by capacitor controller which is detect AC voltage and control ceramic capacitor. Applications Key Specifications Spot light without dimming AC Input range 80 to 275V AC Desk ramp without dimming Input Voltage range(AUX pin) 10 to 38V Down light without dimming Operating temperature -40 to 100 Base light without dimming Accuracy of output current 1.5 %( Typ.) Typical Application Circuits VBUCK R :200k RAUX2:1k AUX1 Cout: 0.1F TR3 CAC: 10F D AUX1:15V D AUX2 DFLY VLED LA: 0.2mH LP: 2mH D BUCK CVDD2: CAUX: VDD2 2.2F 0.47F AUX VDD2 VDET DVDD VDD1 CVDD1: DVDD2 2.2F TR1 VOUT CSEL ISENSE TESTO RISET: 1.5 GNDA SOFT GND OSC RSOFT: ROSC: 100k 100k Fig.1 Typical Application Circuit Product structureSilicon monolithic integrated circuit This product is not designed protection against radioactive rays .w ww.rohm.com TSZ02201-0F2F0C300010-1-2 2012 ROHM Co., Ltd. All rights reserved. 1/15 TSZ2211114001 03.AUG.2012 Rev.001Datasheet BD555A1AFV Absolute Maximum Ratings (Ta=25C) Parameter Symbol Ratings Unit Conditions VDD2, DVDD, DVDD2, Maximum Applied Voltage 1 VMAX1 4.5 V OSC, SOFT, ISENSE PIN VDET, VDD1, VOUT, Maximum Applied Voltage 2 VMAX2 15.5 V CSEL, TESTO PIN Maximum Applied Voltage 3 VMAX3 40.0 V AUX PIN *1 Allowable Power Dissipation Pd1 874.7 mW Operating Temperature Topr -40 +100 Storage temperature Tstg -55 +150 *1 When being mounted on 1 layer substrate(ROHM typical board). 2 Copper layer area is 20.2mm . When being used at over Ta=25C, Pd1 decreases by about 7.00mW/C. Recommended Operating Range (Ta=-40C ~ +100C) Ratings Parameter Symbol Unit Conditions Min. Typ. Max. Operating supply voltage AUX 10 16 38 V Electrical Characteristics (Unless specified, AUX=16V, Ta = +25C) Ratings Parameter Symbol Unit Conditions Min. Typ. Max. Circuit Current Operating Current 1 7.0 14.0 22.0 At Start-up, AUX=7.0V Idd1 A 1.5 2.5 3.5 Operating Current 2 Idd2 mA When stopping switching Regulator VDD1 Voltage VVDD1 11 12 13 V With no-load VDD1 Low Voltage Detection Voltage Vuvlo1 4.0 5.0 6.0 V When AUX is falling VDD2 Voltage VVDD2 2.9 3.3 3.7 V With no-load AUX Start-Up Voltage Vstup 7.45 8.50 10.00 V When AUX is rising AUX Low Voltage Detection Voltage Vuvloaux 6.00 6.50 7.45 V When AUX is falling Switching Regulator Oscillating Frequency Fosc 90 100 110 kHz Rosc=Open Maximum Duty Dmax - 75.0 - % Average Current Sense Voltage Visns 475 500 525 mV Current Sense Blank-Time Tisns 360 400 440 nsec t VOUT High On-Resistance Rvouth 3.0 7.0 16.0 IVOUT=20mA Source VOUT Low On-Resistance Rvoutl 2.0 4.5 12.0 IVOUT=20mA Sink Capacitor Controller AC Input H Deth 340 420 500 mV When VDET is rising Detection Voltage AC Input L Detl 240 300 360 mV When VDET is falling Detection Voltage VDET Input Voltage Range VVDET -0.3 - 9.0 V CSEL On-Resistance RonCS - 10 100 ICSEL=2mA Sink CSEL Off-Leakage IleakCS - - 1.0 A CSEL=10V www.rohm.com TSZ02201-0F2F0C300010-1-2 2012 ROHM Co., Ltd. All rights reserved. 2/15 TSZ2211115001 03.AUG.2012 Rev.001