High voltage high side MOSFET driving

Hi!

I need to design a high voltage high side MOSFET switch configuration, using n-channel IRFP460. Type of load is inductive (0,3H - 0,5H). Switching frequency is variable - in a range of 100Hz - 4kHZ. Is there a possibility to drive the gate of this MOSFET with IR2110? If it is, how should be chosen the bootstrap capacitor? What is the maximum Vbs quiescent current, and how is it determined? How to determine the minimum voltage between Vb and Vs? If this IC can not be applied, what kind of circuit should be used?

Thanks

A mosfet is driven by voltage rather than current. (Whereas transistors operate on a bias current.)

A typical N-channel enhancement-mode mosfet operates on a gate voltage of 2 to 5V. Tiny current might flow through the gate.

I tried to make an inverter by pulsing several amps through the low V side of a large transformer. Perhaps your setup is similar?

I found that a problem emerged in the form of high voltage spikes at each transition. These are caused by inductive kick. Several ringing waves followed. You can expect such spikes to occur in your setup as well.

I burned a few mosfets as I tried to overcome the problem.

I smoothed the transitions a little. But the result was to heat up the mosfets, due to them spending more time in transition, dropping voltage.

I added capacitors of different values across the coil(s). This had the effect of smoothing the transitions, which heated up the mosfets.

Diodes across the coils (another cure which is typically used) did not altogether cure the ringing waveforms.

for high side switching only you will still need an isolated 12-15VDC supply going up to the hide side part of the IR2110, regards, Orson Cart.

The IR2110 is a bootstrapped half bridge driver and its lower frequency operation
is going to be limited by the size of the fly cap and the bleed current of the high
side driver circuitry. Now the 2110 is not a spectacularly high voltage device if
I recall. But it is pretty well known. I believe it is meant for the older 10V-ish
power FETs and may have a UVLO issue if you're trying to drive logic level
power devices. If not then you can expect a weaker output drive at 5V rail.

A proper snubber may be wanted at the load(s).

Hi!

Thank You all for the reply. In the application of IR2110, the low frequency was, so far, the limiting factor because of bootstraping capacitor. Due the fact that this is the testing circuit, I've searched the P channel 500V / 20A power mosfets - and found this one IXTH20P50P-ND. It's not cheap as IRFP460, but for now it will serve it's purpose. Other option is IRF9640 in paralell operation. These MOSFETs will be driven by TC426 or TC4426 inverting mosfet drivers. Thanks once again.