What role does the MOS tube play in synchronous rectification?

Synchronous rectification is a common power management technology, usually used in DC-DC converters. It can control the direction of current through two MOS tubes and transmit electrical energy to the load.

 For example, this synchronous rectification topology circuit uses two MOS tubes . When the upper MOS tube is cut off , the lower MOS tube will be turned on , and the current flows from the inductor to the lower MOS tube.

 When the output current is relatively large, the efficiency of synchronous rectification is relatively high . Generally, when the load is 1A, the efficiency can reach 95%. This is related to the on-resistance of the MOS tube . When it is turned on, the on-resistance of the MOS tube on the lower side is low, and the loss is naturally low. Synchronous rectification is often used in many step-down DCDC circuits .

 In other words, the selection of MOS tube is very important, and we need to consider the following important parameters:

-Voltage rating: Suitable voltage rating to avoid breakdown and damage

-Current carrying capacity: large enough current carrying capacity to effectively cope with load changes and current peaks;

- Turn on/off speed: Fast switching speed can reduce power consumption and improve efficiency

-On-resistance: MOS tubes with low on-resistance can also reduce power consumption and improve efficiency

Here we can recommend VBsemi's MOS tube, which can efficiently meet the requirements of MOS tube in synchronous rectification circuit design. Various parameters and packaging can effectively improve the efficiency and reliability of the system.

Some of the above pictures and information are from the Internet