Rev. 1.30

8

June 26, 2015

HT7L4811

0

5

10

15

20

25

90

100

115

135

180

220

240

264

AC Input (VAC)

E27 8W (13S, 162mA)

T8 18W (12S, 425mA)

Figure 14. E27/T8 THD vs. Wide AC Voltage

Note:*425mAistypicalcurrentlimit.ActualLEDcurrentwillbevariableduetosenseresistortolerance.

Typical Application Circuit

90Vac~ 265Vac

LED+

LED-

DRV

GND

VCC

ZCD

CS

COMP

HT7L4811

Application Information

TheHT7L4811isauniversalAC/DCLEDdriver

designedforLEDlightingapplications.Thedevice

can achieve high Power Factor values without

resortingtoadditionalcircuitsandcanalsogenerate

highaccuracyLEDdrivecurrentswithveryfew

externalcomponents.Separategroundsareprovided;

oneisafloatinggroundfortheHT7L4811whilethe

otheroneistheearth.Usersshouldbeawarethatthe

twogroundscannotbedirectlyconnectedtogetherto

avoidICdamageandsystemmalfunction.

Start-up Current

Averylowstart-upcurrent,ISTART,allowstheusers

toselectalargervalueofstart-upresistorwhich

reducespowerdissipation.

VCC Under Voltage Lockout – UVLO

ThedeviceincludesaUVLOfeaturewhichhas8V

hysteresis.ThePWMcontrollerturnsonwhenVCC

ishigherthan18VandturnsoffwhenVCCislower

than10V.Thehysteresischaracteristicsguarantee

thatthedevicecanbepoweredbyaninputcapacitor

duringstart-up.Whentheoutputvoltageincreases

toacertainvalueafterstart-up,VCCwillbecharged

byanoutputthroughanauxiliarywindingoraZener