Capacitor between PH and BOOT
D/S p.14 BOOST CAPACITOR (BOOT) says it
(e.g. 100nF for 500kHz/5V and 220n for 500kHz/8V.)
How should I have selected the capacitor between Boot as PH?
I make a capacitor between PH and Boot 0.47uF.Will not there be a problem?
Kei,
It may actually not be better by increasing the value of CBOOST. I am not familiar with this controller, but often there can be a race condition between the BOOT voltage and the Vin voltage. When there is a brief power-down / power-up sequence, there can be issues if the BOOT voltage is higher than Vin.
Normally you want to choose a CBOOST that results in about a 0.2Vp-p ripple (on CBOOST) during operation. Making it too big can cause issues, and it only has to be big enough to properly drive the FET gate.
MC.