Estimating Output Current Tolerance Of A Primary–Side-Regulated Constant-Current Flyback Converter (Part 1): The Analytical Model

Focus:

The primary-side-regulated (PSR) flyback converter is widely used in the LED drive market and in the portable electronic market for travel adapters. In such converters, the output current can be estimated by sensing the current in the primary-side MOSFET. LED driver manufacturers are usually targeting ±5% accuracy on current regulation at a given input voltage. Using worst- case circuit analysis techniques, this article will detail how to estimate the accuracy of the flyback output current and compare the obtained results against the ±5% target. The first part of this article derives an analytical model of the primary-side constant-current flyback control scheme. After reviewing the differences between primary-side-regulated and secondary- side-regulated flybacks, it then derives the analytical model of the PSR flyback, then verifies the model experimentally using a 10-W LED driver based on the NCL30082 controller IC.

What you’ll learn:

• How to model the output current and predict the output current tolerance of a primary-side regulated flyback converter

View the Source

Author & Publication:

Stéphanie Cannenterre, ON Semiconductor, Toulouse, France, How2Power Today, Jan 15 2018

This article summary appears
in the HOW2POWER Design Guide.

The Design Guide offers
organized access to
hundreds of articles
on dozens of power conversion
and power management topics.

The Design Guide search results
include exclusive summaries
and accurate "how to" analysis
to help you make faster,
more informed decisions.

Search
for more articles