Loss characteristics of MOS DIODES

Loss characteristics of MOS DIODES

Whether it is NMOS or PMOS, there is an on-resistance after conduction, and the current will be consumed by the resistance, and the energy consumed by this part is called conduction loss. The on-resistance of low-power MOS transistors is generally about a few milliohms to tens of milliohms, and choosing a MOS tube with small on-resistance will reduce the conduction loss.

When the MOS tube is on and off, the voltage at both ends has a falling process, and the current flowing through has a rising process, during this time, the loss of the MOS tube is the product of voltage and current, which is called switching loss. Switching losses are typically much larger than conduction losses, and the faster the switching frequency, the greater the loss.

The greater the product of voltage and current at the moment of conduction, the greater the loss. Shortening the switching time can reduce the loss during each conduction; Reducing the switching frequency can reduce the number of switching times per unit time. Both methods reduce switching losses.