# Boost converter switch current computation verification

I need to have a boost converter in my design in order to provide 5V to the entire system. According to all datasheets I could gather, the total current of the board should not be above 1.5A. So, the parameters are the following :

Param Value
Vin Min 2,8
Vin Max 4,2
Vout 5
Iout 1,5
Efficiency 0,8

Using the wordeful app note from TI (https://www.ti.com/lit/an/slva372c/slva372c.pdf) and using these equations

I have a max switching current from about 3.75 A. Does it sound correct to you guys ?

3.75A is quite plausible. Make sure to calculate the power dissipation in your MOSFET - even if the FET can handle 5A or so theoretically, it might still overheat due to inadequate cooling.

• Thanks, will do ;)
– Ando
Commented Aug 27, 2021 at 7:45

I have a max switching current from about 3.75 A. Does it sound correct to you guys?

Taking account of the output Schottky diode volt drop of about 0.3 volts and, guessing an operating frequency of 100 kHz and inductor value of around 7 μH, with the input voltage at 2.8 volts, the peak current taken from the input source will be around 3.75 amps: -

Internet boost converter calculator

That particular design will be running in CCM with a duty cycle of about 47%. MOSFET losses might cause the efficiency to drop slightly below 90% but it totally depends on the quality of components you use.