The drive for greatly increased power densities in switch mode power supplies (SMPS) is dramatically pushing the switching frequency up as a method for increased power density.

The drive for greatly increased power densities in switch mode power supplies (SMPS) has pushed switching frequencies to one megahertz and beyond.

Previous to the ceramic output filter capacitor, a high energy discharge capacitor has been manufactured for the past 20 years. The application was military and replaced a reconstituted mica that was 20 times its volume and mass.

This slide shows a synchronous buck converter. It is similar to the previous synchronous buck converter except the diode is paralleled with another transistor.

This example converts a 12 volt power source to an output of 5 volts with a 2 amp load. Switching frequency is selected at 400 kHz.

When a power supply is first plugged in or turned on, there is a large current surge into the power supply as the input capacitors are charged.

Soft start is the process of actively controlling the power supply so the output voltages rise at a controlled rate at power on.

Lightning and Electrical equipment on AC power lines can generate very high voltage spikes between 1 to 20,000 volts lasting from a half to 50 microseconds.

Voltage trimming is often supplied on a power supply to enable the user to adjust the output voltage slightly to compensate for system oriented voltage drops or to compensate for unit to unit variations of the power supply.

Power supply usually incorporates circuitry that inhibits the operation of the power supply if the input supply voltage is too low or too high. Low input voltage that are stressful to a power supply because the input current rises as the input voltage drops.