
TOP242-250
2
H
9/02
General Information & Table of Contents
Product Selector Guide
1
Data Sheets
2
Application Notes
3
Design Ideas
4
Design Tools
5
Quality and Reliability
6
Package Information
7
DPA-Switch DC-DC Seminar
8
LinkSwitch & TinySwitch-II AC-DC Seminar
9
TOPSwitch-GX AC-DC Seminar 10
Sales Representatives and Distributors 11
Section List
Functional Block Diagram ......................................................................................................................................... 3
Pin Functional Description ........................................................................................................................................ 4
TOPSwitch-GX Family Functional Description ........................................................................................................ 5
CONTROL (C) Pin Operation ................................................................................................................................. 6
Oscillator and Switching Frequency ....................................................................................................................... 6
Pulse Width Modulator and Maximum Duty Cycle ................................................................................................. 7
Light Load Frequency Reduction ............................................................................................................................ 7
Error Amplifier ......................................................................................................................................................... 7
On-chip Current Limit with External Programmability ............................................................................................. 7
Line Under-Voltage Detection (UV) ........................................................................................................................ 8
Line Overvoltage Shutdown (OV) ........................................................................................................................... 8
Line Feed Forward with DC
MAX Reduction .............................................................................................................. 8
Remote ON/OFF and Synchronization ................................................................................................................... 9
Soft-Start ................................................................................................................................................................ 9
Shutdown/Auto-Restart .......................................................................................................................................... 9
Hysteretic Over-Temperature Protection ................................................................................................................ 9
Bandgap Reference ................................................................................................................................................ 9
High-Voltage Bias Current Source ........................................................................................................................ 10
Using Feature Pins .................................................................................................................................................... 11
FREQUENCY (F) Pin Operation ........................................................................................................................... 11
LINE-SENSE (L) Pin Operation ............................................................................................................................ 11
EXTERNAL CURRENT LIMIT (X) Pin Operation ................................................................................................. 11
MULTI-FUNCTION (M) Pin Operation .................................................................................................................. 12
Typical Uses of FREQUENCY (F) Pin ...................................................................................................................... 15
Typical Uses of LINE-SENSE (L) and EXTERNAL CURRENT LIMIT (X) Pins ....................................................... 16
Typical Uses of MULTI-FUNCTION (M) Pin ............................................................................................................. 19
Application Examples ............................................................................................................................................... 21
A High Efficiency, 30 W, Universal Input Power Supply ........................................................................................ 21
A High Efficiency, Enclosed, 70 W, Universal Adapter Supply .............................................................................. 22
A High Efficiency, 250 W, 250 - 380 VDC Input Power Supply ............................................................................. 23
Multiple Output, 60 W, 185 - 265 VAC Input Power Supply .................................................................................. 24
Processor Controlled Supply Turn On/Off ............................................................................................................ 25
Key Application Considerations .............................................................................................................................. 27
TOPSwitch-II vs. TOPSwitch-GX .......................................................................................................................... 27
TOPSwitch-FX vs. TOPSwitch-GX ....................................................................................................................... 28
TOPSwitch-GX Design Considerations ................................................................................................................ 29
TOPSwitch-GX Layout Considerations ................................................................................................................. 31
Quick Design Checklist ......................................................................................................................................... 31
Design Tools ......................................................................................................................................................... 33
Product Specifications and Test Conditions .......................................................................................................... 34
Typical Performance Characteristics ...................................................................................................................... 41
Part Ordering Information ........................................................................................................................................ 45
Package Outlines ...................................................................................................................................................... 45