boost converter efficiency

[satya82]

Hi Forum

I would like to know is the capacitor value will effect the efficiency for boost converter? In my hardware design first capacitor value of 2uF were used and gave 67% efficiency. Secondly, capacitor value 0.68of were used and gave 78% efficiency and lastly capacitor value of 1uF used and gave 82% efficiency.

need your advice

thank you

 

[schmitt trigger]

More than the actual capacitance, the capacitor's ESR will be the one affecting the efficiency.

What type of capacitors were you using? What frequency are you switching?

 

[satya82]

switching frequency is 400khz and used ceramic and polyester film capacitor.

 

[schmitt trigger]

Film caps have lots of equivalent series inductance, not a good choice for 400 khz.

And ceramic caps are the best, as long as you are using MLCCs.

 

[smijesh]

Ceramic capacitors are the best choice, Use parallel multiple capacitor instead of single one it will reduce ESR and high frequency ripple. Hence higher efficiency
Cout.min = Output Current*Duty cycle/ Switching Frequency**Output ripple voltage