ZHCS547K January 2010 – February 2018 LM27402
PRODUCTION DATA.
Selecting the correct power MOSFET for a design is important to the overall operation of the circuit. If inappropriate MOSFETs are selected for the application, it may result in poor efficiency, high temperature issues, shoot-through and other impairments. It is important to calculate the power dissipation for each MOSFET at the maximum output current and ensure that the maximum allowable power dissipation is not exceeded. MOSFET data sheets must also specify a junction-to-ambient thermal resistance (θJA), and the temperature rise is estimated from this specification.
Both high-side and low-side MOSFETs contribute significant loss to the system relative to the other components. The high-side MOSFET contributes transition switching loss, conduction loss and gate charge loss. The low-side MOSFET also contributes conduction and gate charge loss, and the body diode of the MOSFET causes deadtime conduction loss and reverse recovery loss that must also be considered. The transition losses for the low-side MOSFET are insignificant and usually ignored.