Dual Output Off-Line Non-isolated Fly-back Power Solution
AP3917B 12V/20mA+3.8V20mA EV3 Board User
’s Guide
AP3917B EV3 Page 1 of 17 06-21-2019
Rev 1.0 www.diodes.com
Table of Content
Chapter1 Induction ................................................. 2
1.1 General Description........................................ 2
1.2 AP3917B Key Features .................................. 2
1.3 Applications .................................................... 2
1.4 Board Picture .................................................. 2
Chapter2 Power Supply Specification .................. 3
2.1 system performance ....................................... 3
2.2 Environment ................................................... 3
Chapter3 Schematic and bill of material .............. 4
3.1 Schematic ....................................................... 4
3.2 Bill of Material ................................................. 4
3.3 Transformer Specification .............................. 5
3.3.1 Electrical Diagram ................................... 5
3.3.2 Transformer Instructions ......................... 5
3.3.3 Electrical Specifications .......................... 5
Chapter4 Evaluation Board Connections ............ 5
4.1 PCB Layout .................................................... 5
4.2 Circuit Description .......................................... 6
4.2.1 Input EMI Filtering ................................... 6
4.2.2 Control IC ................................................ 6
4.2.3 Flyback block .......................................... 6
4.2.4 Output Rectification ................................ 6
4.2.5 Output Feedback .................................... 6
4.3 Quick Start Guide ........................................... 6
Chapter5. System test ............................................ 7
5.1 Input & Output Characteristics ....................... 7
5.1.1 Input Standby Power .............................. 7
5.1.2 Efficiency ................................................. 7
5.1.3 Line Regulation ....................................... 8
5.1.4 load regulation ........................................ 9
5.2 Key Performance test ..................................... 9
5.2.1 Start up performance .............................. 9
5.2.2 Voltage Stress....................................... 10
5.2.3 Output Ripple & Noise .......................... 11
5.2.4 Dynamic Response ............................... 12
5.3 Protection(SCP) test .................................... 13
5.4 Thermal Test ................................................ 14
5.5 System EMI Scan ......................................... 15
5.5.1 Conduction EMI test of 230V@full load 15
5.5.2 Conduction EMI test of 110V@full load 16