NJW4170

- 21 -

Ver.2016-01-25

Calculation of Package Power

A lot of the power consumption of buck converter occurs from the internal switching element (Power MOSFET).

Power consumption of NJW4170 is roughly estimated as follows.

Input Power:

Output Power:

Diode Loss:

Where:

: Input Voltage for Converter

: Input Current for Converter

: Output Voltage of Converter

: Output Current of Converter

: Diode's Forward Saturation Voltage

: Inductor Average Current

OFF duty

: Switch OFF Duty

Efficiency ( ) is calculated as follows.

You should design power consumption in rated range referring to the power dissipation vs. ambient temperature

characteristics.

Technical Information

NJW4170 Application Manual