## Flyback Diode Voltage and Current Analysis

Flyback Converter diode is acting like a switch linking the transformer secondary and the load. When the primary switch is ON, the primary will store energy. This time the diode will be reversed biased. Meaning, the load side will be cut off from the transformer. On the other hand, when the primary switch is off, the stored energy will be

## Transformer Design and Selection QR Flyback

Several factors to consider in order to perfectly arrived a good Quasi Resonant Flyback transformer design. It needs to consider the input voltage and the allowed level of the switch drain to source (or collector to emitter) voltage of the switch to define the level of the reflected voltage (Vref). It is also required to know the level of the

## How to Derive QR Flyback Secondary Current

The key to deriving the current levels of every switching converter knows the type of waveforms. For flyback converter, the primary and secondary current waveforms are in triangular shape. Another important aspect is to know the operation of a QR flyback. The complete operation of a QR flyback is here. The current wave shape is could be summarized as: The

## Importance of DFMEA in Product Development

The importance of DFMEA in product development is cannot be underestimated. It is an analysis that is good for both product robustness and overall safety. However, this design tool is not adopted by all product developers. The main reason is that this tool is maybe time consuming and needs a highly experienced design engineer to do so. DFMEA Definition DFMEA

## LLC Converter Gain-Frequency Curve

The gain-frequency curve of an LLC resonant converter is a graphical guide displaying both the gain and operating frequency. At resonance frequency, the gain is certain to be unity. However, at above or below the resonance, the gain is no longer unity. In this article we will cover how LLC converter gain-frequency curve works or how to interpret it and

## Why LLC Resonant Converter Gain is Unity

You may be wondering why LLC resonant converter gain is unity. How it happens and how to mathematically derive it. If you have these questions, then you are on the right page. I will be sharing to you the answers to these questions. In the previous topic, I discussed the equivalent AC circuit of an LLC resonant converter. Read How

## MOSFET Selection for Buck Converter

Buck converter can be synchronous or non-synchronous type. The former uses a MOSFET (or BJT, IGBT) in place of the buck diode. Basically, there are two switches in synchronous type. On the other hand, the latter uses a switch and a diode combination. This is simpler and cheaper than the former since there is only a single MOSFET to control.

## Junction to Case Thermal Resistance

Junction to case thermal resistance is measured from the junction to the case. This is mostly specified for power semiconductor devices. This article will teach how to use it and when to use it. Junction to Case Thermal Resistance Symbol and Units Some datasheets use RthJC while others use RθJC. They are referring to the same parameter. The units used