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On different forums, I often find people asking for help in calculating the required turns for a ferrite transformer they are going to use in offline SMPS half-bridge converter s . The half-bridge topology is very popular for offline converters in the power range 100W to 500W, sometimes goin g up to even 1000W. In an offline SMPS half-bridge converter, the line voltage is rectified and filtered and is then converted to high frequency with 2 MOSFETs – one in high-side configuration and the other in low-side configuration. This high frequency high voltage AC is fed to the ferrite transformer to step down the voltage to low voltage high frequency AC which is then rectified to DC and filtered to provide clean DC output. A vital thing to remember is that in a half-bridge converter, the 2 MOSFETs work along with 2 capacitors to create the high voltage high frequency AC. The configuration of the capacitors, MOSFETs and transformer causes the transformer to be supplied half the voltage of the...

In many situations, we need to use MOSFETs configured as high-side switches. Many a times we need to use MOSFETs configured as high-side and low-side switches. Such as in bridge circuits. In half-bridge circuits, we have 1 high-side MOSFET and 1 low-side MOSFET. In full-bridge circuits we have 2 high-side MOSFETs and 2 low-side MOSFETs. In such situations, there is a need to use high-side drive circuitry alongside low-side drive circuitry. The most common way of driving MOSFETs in such cases is to use high-low side MOSFET drivers. Undoubtedly, the most popular such driver chip is the IR2110. And in this article/tutorial, I will talk about the IR2110. You can download the IR2110 datasheet from the IR website. Here's the download link: www.irf.com/product-info/datasheets/data/ir2110.pdf First let’s take a look at the block diagram and the pin assignments and pin definitions (also called lead assignments and lead definitions): Fig. 1 - IR2110 block diagram (click on image to enlarge)...