Sorry I had not seen this ... C66 = 1uF
I've no experience with the larger IPR ... write to Peavey support and ask ... they've always been good at answering my questions, you can also buy spare components from them ... let us know what happens.
Surely the place that lost the capacitor should be replacing it? ... also no idea why he would remove it in the first place?
Good luck!
I've no experience with the larger IPR ... write to Peavey support and ask ... they've always been good at answering my questions, you can also buy spare components from them ... let us know what happens.
Surely the place that lost the capacitor should be replacing it? ... also no idea why he would remove it in the first place?
Good luck!
You may replace it with a good quality polypropylene / ceramic / aluminium electrolytic capacitor of similar value, with no consequences. This (bootstrap) capacitor is just a part of the charge-pump that supplies the high-side gate driver and is therefore not very critical.I recently sent my peavey IPR2 7500 for IR2110 chip replacement and the guy lost a silver capacitor (C1060 in schematics) near the chip, in the case of IPR 1600 it shows as C66 in schematics, i was wondering if any of you knows the value or where to get a replacement
If it is indeed the 'bootstrap' capacitor (providing turn-on bias for the upper MOSFET), the selection is not trivial. Many aluminum electrolytics are not up to the task. It has to be able to fully charge in as little as 3 to 5% on-time of the lower MOSFET. That requires low ESR, low inductance, and the correct value.
Cheers
Cheers
I fully disagree with Rick PA Stadel, as the bootstrap capacitor does not completely discharge along with the MOSFETs' gates and therefore there is no question of "fully charging" it within the cycle. In fact, the voltage across this capacitor stays more or less at a constant value (~Vcc -Vcom) from turn-on to turn-off, as it is usually sized at more than 100x the gate capacitance, to keep any voltage drops negligible.
Moreover, it is not recommended to use unusually low ESR capacitors for bootstrap storage, as the charging currents need to be limited to modest values. Some designs also add a small resistor (<10R) in series to achieve this.
Further, I've used all kinds of capacitors for this purpose including aluminium electrolytic and have never had a problem with the high-side gate-drive. And I'm also fairly sure that a "silver capacitor" is not necessary.
Moreover, it is not recommended to use unusually low ESR capacitors for bootstrap storage, as the charging currents need to be limited to modest values. Some designs also add a small resistor (<10R) in series to achieve this.
Further, I've used all kinds of capacitors for this purpose including aluminium electrolytic and have never had a problem with the high-side gate-drive. And I'm also fairly sure that a "silver capacitor" is not necessary.
Sorry -- I was only considering the first few cycles -- just to make sure the output filter inductor gets reset each cycle.
Wonder where it was that I remember reading those bits about it -- IR's app notes, probably.
Aren't the charge-current-limiting resistors (<10R) in series with the charging diode?
Best Regards
Wonder where it was that I remember reading those bits about it -- IR's app notes, probably.
Aren't the charge-current-limiting resistors (<10R) in series with the charging diode?
Best Regards
The bootstrap capacitor would still charge through the load circuit in most cases. This is especially true for a buck converter in which the bottom device being a diode, is unable to provide the capacitor with a path for its charging current.
Likely, from the following:
HV Floating MOS-Gate Driver ICs
Low ESR doesn't do much good as the low-side MOSFET appears in series but it may be best to avoid very low ESR types. The typical 100nF ceramic capacitor works well and is a popular value used by many people. At 1uF, polyester / PP is probably the one to get. Nevertheless, electrolytic capacitors are not altogether forbidden.
Yes, that prevents the capacitors CVcc and Cboot from appearing directly in parallel with each other, thereby also extending the life of the bootstrap diode.