Calculate Value of Cboost & Leakage Current

[billy fok]

currently am using high side driver and i need to calculate the value of Cboost.
may i how i determine the "Bootstrap capacitor leakage current".

 

[Svein]

Show a figure or a schematic, otherwise we cannot answer.

 

[billy fok]

Show a figure or a schematic, otherwise we cannot answer.

I hope that i have attached the right schematic. I apply 15v to Vcc and 5v pulse to IN.
when i measure HO is zero. but i need to have 15V output from my HO. hope you are able to help me

 

[davenn]

so what is the chip ?
what does its datasheet say about it's use ?
post a link to the datasheet

Dave

 

[billy fok]

so what is the chip ?
what does its datasheet say about it's use ?
post a link to the datasheet

Dave

thanks for the reply! http://www.rcscomponents.kiev.ua/datasheets/irs21850spbf.pdf

 

[Baluncore]

This appears to be a continuing problem of insufficient data.
https://www.physicsforums.com/threads/working-of-driver.805987/#post-5059370

The chip is probably still the IRS21850S, SINGLE HIGH SIDE DRIVER IC.
The value of the boost capacitor will be dependent on the output load capacitance and the clock rate.

 

[davenn]

This appears to be a continuing problem of insufficient data.
https://www.physicsforums.com/threads/working-of-driver.805987/#post-5059370

The chip is probably still the IRS21850S, SINGLE HIGH SIDE DRIVER IC.
The value of the boost capacitor will be dependent on the output load capacitance and the clock rate.

ah hah

Billy fok
some advice ... if you want people to help you and give your good answers
You really have to please start supplying ALL the information in your posts
none of us are mind readers

regards
Dave

 

[Baluncore]

The procedure for calculation of C_boost can be found in IR application note AN-1123.
http://www.irf.com/technical-info/appnotes/an-1123.pdf

See pages 9 through to page 12, where C_boot > Q_tot / V_drop.
We do not know the part number of the driven MOSFET/IGBT gate so we cannot know Q_tot, the total gate charge.