Infineon XDPL8218, Design Manual

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Design Guide Please read the Important Notice and Warnings at the end of this document V 1.0
www.infineon.com/XDPL8218 page 1 of 48 2018-06-06
DG_1711_PL21_1802_031149
XDPL8218 design guide
For high power factor flyback converter with constant voltage output
About this document
Scope and purpose
This document is a design guide using XDPL8218 as the control IC of the front-stage High Power Factor (HPF)
flyback converter, which regulates the secondary output voltage supply to the second-stage Constant Current
(CC) converter for LED lighting applications.
Intended audience
Power supply design engineers, field application engineers.
Table of contents
About this document ....................................................................................................................... 1
Table of contents ............................................................................................................................ 1
1 Introduction .......................................................................................................................... 3
2 Design specifications .............................................................................................................. 5
3 Transformer design ................................................................................................................ 6
4 Flyback MOSFET and secondary main output diode selection ...................................................... 8
5 CS resistor and GD pin-related design ...................................................................................... 10
6 MOSFET maximum current cycle-by-cycle limit and start-up phase design .................................. 11
7 HV pin-related design ............................................................................................................ 14
8 V
CC
capacitance and output UVP design .................................................................................... 15
9 Output OVP-related design ..................................................................................................... 17
10 DC link filter and secondary main output capacitance ............................................................... 18
11 Input voltage levels for start-up and protection ....................................................................... 19
12 ZCD pin-related design ........................................................................................................... 20
13 Secondary-side regulation FB circuit design ............................................................................. 22
14 Regulated mode parameters .................................................................................................. 26
14.1 Digital notch filter .................................................................................................................................. 26
14.2 On-time limit and switching frequency limit (QRM1/DCM) ................................................................. 26
14.3 ABM FB voltage sensing and control .................................................................................................... 27
14.4 FB voltage mapping and mode transition ............................................................................................ 28
14.5 FB voltage maximum limit ramp .......................................................................................................... 29
15 Other protection-related parameters ...................................................................................... 30
15.1 V
CC
OVP ................................................................................................................................................... 30
15.2 Regulated mode V
CC
UVP ....................................................................................................................... 30
15.3 IC over-temperature protection ........................................................................................................... 30
15.4 Primary MOSFET over-current protection ............................................................................................ 30
15.5 Debug mode .......................................................................................................................................... 31
16 PCB layout guide ................................................................................................................... 32