Capacitor for Bootstrap in BRD1260c
Hi Team,
We are using BRD1260C IC in one of our motors application. The BPH (Bootstrap Cap) we are using
is 4.7uF. Our motor frequency is around 45Hz to run with 1400RPM. so is the Bootstrap capacitor value sufficient? or do we need more value?
The Top & bottom pulse is having duty of 30% respectively.
Comments
Hi,
Good day.
The BPH capacitor which supplies the high-side controller bias current is a function of the commutation duty ratio and PWM frequency. Please see attached file for reference in determining the minimum value of capacitor needed for the BPH. Minimum recommended value is 0.33uF and 4.7uF may be enough but still kindly double check since this will also depend on your switching frequency.
In addition kindly see below link for additional reference. BPH selection is on page 5 of the datasheet.
https://www.power.com/sites/default/files/documents/bridgeswitch_family_datasheet.pdf
Thank you very much.
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