What are the losses in MOSFET?

What are the losses in MOSFET?

Power loss in a rectifier MOSFET consists of conduction losses (PCON), body-diode conduc- tion losses (PBD), and gate losses (PGATE). There are no switching losses because of the body diode. The body diode conducts and the voltage across the FET is the diode voltage, which is zero.

What is Eoss MOSFET?

When the MOSFET is turned off, the stored energy in Coss discharges via the body diode and causes the turn-on loss. The energy dissipated by Coss is denoted as Eoss in the datasheet. Or: The power loss due to Coss is different for MOSFETs with different structures as shown below.

What are switching losses?

Switching losses occur when the power switch or rectifier is transitioning between the ON state to the OFF state and vice versa. These are frequency depend- ent since there are more transitions per second at higher frequencies.

How does MOSFET reduce switching losses?

In general, a higher switching frequency and higher input voltage require a lower QG (gate charge) to cut down the switching losses in the switch MOSFET (Q1). For a rectifier MOSFET (Q2), low RDS(on) is most important, but don’t ignore the gate power.

What causes switching losses?

Switching losses occur when the device is transitioning from the blocking state to the conducting state and vice-versa. The energy dissipated in each transition needs to be multiplied by the frequency to obtain the switching losses; Conduction losses occur when the device is in full conduction.

How is switching loss measured?

It takes a capable oscilloscope to make the measurements, but a number of oscilloscopes have the right features for measuring switching loss, namely:

1. Compatible differential voltage and current probes.
2. Ability to correct delay between voltage and current channels (deskew)
3. Waveform multiplication.
4. Measurement gating.

What is Ciss and Coss?

Capacitances Ciss Crss Coss pF Ciss is the input capacitance, Crss is the reverse transfer capacitance, and Coss is the output capacitance. Capacitances affect the switching performance of a power MOSFET.

Why do switching losses occur?

How do you calculate switch losses?

The switching losses during the transition from the off to the on state say on transition and vice verse say off transition can be calculated by the formula: Eon= Integral vD iD dt , on the the on time ton, and the same formula for the off period toff as an integration interval.

Which is power MOSFET family does Infineon use?

Infineon’s highly innovative OptiMOS™ and StrongIRFET™ families consistently meet the highest quality and performance demands in key specifications for power system design such as on-state resistance and figure of merit characteristics.

Which is the maximum voltage for automotive MOSFET?

The maximum voltage for automotive MOSFET is limited to 650V today. There is no plan for higher voltage classes in the near future. The gate charge is a function of the die geometry, i.e. die area and thickness of the gate dielectric. These are very stable parameters.

Which is the most reliable MOSFET in the industry?

Designs requiring the highest quality and enhanced protection features benefit from Infineon’s automotive qualified n-channel and p-channel MOSFETs which go beyond AEC-Q101 industry standards providing the most reliable MOSFETs in the industry.