Electronic Components Datasheet Search |
|
B72207S0271K101 Datasheet(PDF) 2 Page - Diodes Incorporated |
|
B72207S0271K101 Datasheet(HTML) 2 Page - Diodes Incorporated |
2 / 12 page AN75 Issue 1 – January 2011 2 www.diodes.com © Diodes Incorporated 2010 sense signal and the switching adjusts to be the sum of the on- and off-time. This change allows the converter to work with duty cycles greater than 50%. Design Guide – High power factor offline LED driver In this section the design procedure is outlined according to the schematic shown in Figure 1. First, the guideline for selecting the components for valley fill power factor correction stage and fixed off- time buck converter is shown. The power inductor calculation is then demonstrated and finally, the power losses within MOSFET and free-wheel diode are assessed. The specifications for the system are: V AC = 230Vac V AC(min) = 85Vac V AC(max)= 264Vac I LED(nom) = 240mA V LED(nom) = 54V V LED(min) = 42V V LED(max) = 59V P OUT = 12.96W f swi(nom) = 55kHz Passive factor correction stage design The purpose of the valley fill circuit (see Figure 2) is to allow the buck converter to pull power directly off the AC line when the line voltage is greater than 50% of its peak voltage. Figure 2 Valley-fill PFC stage and operating waveforms (Green: VIN to LED driver; Orange: AL9910’s gate voltage) The maximum bus voltage at the input of the buck converter is, V 373 Vac 64 2 2 V 2 V ac(max) IN(max) = × = × = During this time, capacitors within the valley fill circuit (C1 and C2) are in series and charged via D2 and R1. If the capacitors have identical capacitance value, the peak voltage across C1 and C2 |
Similar Part No. - B72207S0271K101 |
|
Similar Description - B72207S0271K101 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |