Design Example Report
Title
Specification
Application
Author
Document
Number
Date
Revision
15W power supply using TNY268P
Input: 120 - 420 Vdc
Output: 5V/3A, 13V/10mA
PC Standby
Power Integrations Applications Department
DER-11
February 4, 2004
1.0
Summary and Features
This report details the design of an isolated Flyback converter for a PC
Standby power
supply
.
•
•
•
•
•
High light load efficiency
Over 0.4W out at 1W in, as measured in the PC PSU
Total output power 15 W with TNY268P and EE19 core
Typical Efficiency 79 %
Meets
±
5 % output voltage regulation over line and load changes
The products and applications illustrated herein (including circuits external to the products and transformer
construction) may be covered by one or more U.S. and foreign patents or potentially by pending U.S. and foreign
patent applications assigned to Power Integrations. A complete list of Power Integrations’ patents may be found at
www.powerint.com
Power Integrations
5245 Hellyer Avenue, San Jose, CA 95138 USA.
Applications Hotline: Tel: +1 408 414 9660 Fax: +1 408 414 9760
www.powerint.com
DER-11
15W PC Standby power supply
February 4, 2004
Table Of Contents
Introduction................................................................................................................. 4
Power Supply Specification ........................................................................................ 5
Schematic................................................................................................................... 6
PCB Layout ................................................................................................................ 7
Bill Of Materials .......................................................................................................... 8
Transformer................................................................................................................ 9
6.1
Transformer Winding........................................................................................... 9
6.2
Electrical Specifications....................................................................................... 9
6.3
Transformer Construction.................................................................................. 10
6.4
Materials............................................................................................................ 10
6.5
Winding Instructions .......................................................................................... 11
6.6
Design Notes:.................................................................................................... 11
7 Transformer Design Spread Sheet........................................................................... 12
Performance Data ........................................................................................................... 14
7.1
Light Load Input and Output Power Comparison
..................................................... 15
7.2
Efficiency comparison, standalone .................................................................... 16
8 Output Ripple Measurements................................................................................... 17
8.1
Ripple Measurement Technique ....................................................................... 17
8.2
Output Voltage Ripple ....................................................................................... 18
9 Revision History ....................................................................................................... 18
Notes ............................................................................................................................... 19
1
2
3
4
5
6
Page 2 of 20
Power Integrations
Tel: +1 408 414 9660 Fax: +1 408 414 9760
www.powerint.com
DER-11
15W PC Standby power supply
February 4, 2004
List Of Figures
Figure 1 – Power Supply Prototype – Top View.............................................................................................. 4
Figure 2 – Power Supply Prototype – Bottom View ........................................................................................ 4
Figure 3 – TNY268 Flyback Converter – 15 W, 5V 3A, 13V 10 mA................................................................ 6
Figure 4 – PCB Layout .................................................................................................................................... 7
Figure 5 – Transformer Winding...................................................................................................................... 9
Figure 6 – Transformer Construction............................................................................................................. 10
Figure 7 – Input vs. Output power at 115 Vac............................................................................................... 15
Figure 8 – Input vs. Output power at 230 Vac............................................................................................... 15
Figure 9 – Efficiency versus output current at 115 Vac................................................................................. 16
Figure 10 – Efficiency versus output current at 230 Vac............................................................................... 16
Figure 11 – Oscilloscope Probe Prepared for Ripple Measurement............................................................. 17
Figure 12 – Oscilloscope Probe with Probe Master 5125BA BNC Adapter .................................................. 17
Figure 13 – 5V Output Voltage Ripple at V
IN
= 115 Vac, I
5V
= 3 A ................................................................ 18
List Of Tables
Table 1 – Power Supply Specification ______________________________________________________ 5
Table 2 – Bill of Materials ________________________________________________________________ 8
Table 3 – Transformer Electrical Parameters_________________________________________________ 9
Table 4 – Transformer BOM_____________________________________________________________ 10
Table 5 – Power Supply Design Parameters ________________________________________________ 11
Important Notes:
Although the prototype hardware is designed to satisfy safety isolation requirements,
this engineering prototype has not been agency approved. Therefore all testing should
be performed using an isolation transformer to provide the AC input to the prototype
board.
The layout shown in this report has been engineered to follow Power Integrations’
design guidelines to minimize EMI and susceptibility. Changing the layout may worsen
EMI and other aspects of performance.
Design Reports contain a power supply design specification, schematic, bill of
materials, and transformer documentation. Performance data and typical operation
characteristics are included. Typically only a single prototype has been built.
Page 3 of 20
Power Integrations
Tel: +1 408 414 9660 Fax: +1 408 414 9760
www.powerint.com
DER-11
15W PC Standby power supply
February 4, 2004
1 Introduction
This document is an engineering report showing the performance characteristics of a 15W
Flyback converter with 120–420Vdc (PFC application) input, 5V 3A isolated output, and 13V
10mA non-isolated output. This design uses
TinySwitch-II
– an integrated IC comprising a high
voltage
MOSFET,
and
PWM
controller.
This document contains power supply specification, schematic, bill of materials, transformer
documentation, printed circuit layout, and performance data. The photos of power supply
prototype are shown in Figure 1 and Figure 2.
Measurements were taken both with the prototype standalone, and in the PC power supply.
Figure 1 –
Power Supply Prototype – Top View
Figure 2 –
Power Supply Prototype – Bottom View
Page 4 of 20
Power Integrations
Tel: +1 408 414 9660 Fax: +1 408 414 9760
www.powerint.com
DER-11
15W PC Standby power supply
February 4, 2004
Note: Y-cap is for testing the unit standalone. Otherwise, The common-mode noise may
affect the input power measurements.
2 Power Supply Specification
Description
Input
Voltage
Outputs
Output Voltage 1
Output Ripple Voltage 1
Output Current 1
Output Voltage 2
Output Ripple Voltage 2
Output Current 2
Continuous Output Power
Efficiency
Ambient Temperature
Symbol
V
IN
V
OUT1
V
RIPPLE1
I
OUT1
V
OUT2
V
RIPPLE2
I
OUT2
P
OUT
η
T
AMB
0
15
79
40
Min
120
4.75
5.0
Typ
Max
420
5.25
50
3
Units
Vdc
V
mV
A
V
130
10
mV
mA
W
%
o
Comment
PFC Standby
±
5%
20 MHz Bandwidth
isolated
13
20 MHz Bandwidth
non-isolated
At full load
Free convection, Sea level
C
Table 1 –
Power Supply Specification
Page 5 of 20
Power Integrations
Tel: +1 408 414 9660 Fax: +1 408 414 9760
www.powerint.com
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
