Hi,
I would like to integrate the ISO5451 in a high power IGBT motor control application in an upcoming design of our company and have a few questions I would like to have clarification about.
1.) Can I use bootstrapping for the high side driver configuration to get rid of an additional isolated dc/dc converter? If so, do you have any design recommendations about that? I target a switching range from 4kHz to 20kHz and so the switching power worst case will be at 4kHz, where the capacitor needs to hold the voltage for 250us. Qg of the IGBT will be around 200nC, Vdd will be 15V, so Cbs > 10 * Qg/Vdd = 133nF. Now also the driver takes some continous current (worst case ICC2 is 6mA), so this leads to additional 10 * ICC2 * 250us / Vdd = 1uF, so in total i should be safe when i take something like 3.3uF as a bootstrap cap, right?
2.) When VCC2 falls low after a DESAT error and the IC turns off on the secondary site, the controller does still latch everything to a safe state and still needs an active nRST trigger?
3.) In the datasheet there is the diode Ddst, that diode should be able to handle the full supply voltage of the motor controller, right?
4.) Does the controller limit the peak currents for source and sink of 2.5/5A respectively as it is done with the smart gate control for MOSFETs from TI? What happen, when the gate resistor is too low, so that the limit would exceed?
Best,
Hans
