PWM control based Half-Bridge Boost Circuit Design with Power Mosfet

Hello,
I want to design a Half-Bridge circuit to boost my low-voltage PWM signals up to 400V. When I search several web sites, I find IR2110 useful for this design. And I decided to design this circuit illustrated belove.
Actually, I have not experience with high voltage, and also such as analog design. I designed all of the low voltage circuits and only this boost circuit remains.
I want to design max 70W circuit and also enough protection for high current and high voltage.
Is this circuit adequate such an application? Can I get your opinion?
With Kind Regards,
Sunay

Sunay,

Where did you find the schematic you posted, could you post a link? Or is it something you created yourself?

What is your load for the boosted PWM? what are you trying to use it for exactly?

There are a few things that seem very odd to me, unless I'm severely misinterpreting the way the circuit is supposed to work.

Why do you have the 400mA fuses F2 and F3 in series with the MOSFET gates? Usually if anything is there it's a small value resistor meant to slow the MOSFET turn on time and soften the peak current the driver IC must source to them.

Why are diodes D5, D6, D7, and D8 placed where they are? I wouldn't think D7 and D8 would do much of anything at all, and that D5 and D6 would just lower your efficiency.

Why is C6 in series with one of your outputs? That would AC couple the output and therefore you wouldn't be able to pass the DC current during the high value of your PWM output.

Depending on the maximum ON time of your PWM and the load that you have attached, you may need a lot more bulk capacitance than just C6 to properly rectify your AC input to a more stable DC voltage and provide enough hold up while it is sourcing power to your load.

You may want to think more about the 4 Amp fuse on the input. The power draw from the 230VAC line would have to be nearly a kW before it would blow, so a smaller one may be a better choice for safety purposes (again, depends on your load). Inrush current during start up would also have to be considered for sizing this fuse, and that might lead to the decision to include some sort of inrush current limiter as well.

If the 70W you mentioned is the direct load for the boosted driver output, then you might need an impractically large bank of capacitors in order to facilitate the necessary energy storage since the boost circuit isn't inductor/transformer based.

Do be very careful during your testing and experimenting. Playing with such things can be extremely dangerous without knowing what you are doing. If you have someone nearby that has safety experience with high voltage power circuits, it is probably a good idea to consult with them about everything beforehand.

Here is some useful information from the "International Rectifier website page":https://ec.irf.com/v6/en/US/adirect/ir?cmd=catProductDetailFrame&productID=IR2110 for the IRF2110. The attached pictures are of the demo board schematic and bill of materials they provide.

You mentioned 400V (which rectified 230VAC wouldn't get you anyway). If you really need to provide a 70W PWM from this high a voltage you should probably be thinking about a more adequate regulated power source to draw from than just capacitors anyway. You could design/build your own AC/DC switching supply to do this, but that would require either the know how or else a lot of determination (and time) to learn how. Such things are usually more difficult than most anticipate. Another option is to just buy a supply or module already designed to provide the voltage and power you need, and then attach it to the VBUS input of the standard IR2210 circuit after you build it. Unfortunately the cheapest supply I could find at Digi-Key that could provide near 400V and at least 70W is much bigger than you probably want and is therefore more expensive than you probably want. Here it is, "the AIT02ZPFC-01NL-ND":http://search.digikey.com/us/en/products/AIT02ZPFC-01NL/AIT02ZPFC-01NL-ND/2203619 , just for the sake of being thorough and to give you the option anyway.

One last note is that a 400V PWM at that sort of power is likely going to radiate all sorts of EMI into the air while it's switching, especially if the load is connected through any length of cable since that will act like an antenna for it. Just something to keep in mind so that it doesn't catch you by surprise later.

Hello Alec,

First of all thanks for your replies.

I want to use this circuit that I mentioned my first post, to drive an ultrasonic transducer which operates nearly 40khz and its power 70W.

So I also want to control frequency and duty cycle, thats why I used a microcontroller to create PWM signal. Then, it needs to amplify this low-voltage PWM signal up to 400V-600V and 70W. So IR2110 is a suitable chip to drive power N mosfet half bridge circuit.

I can get dc supply by using rectifier diodes, and its not so important to get great dc supply anyway.Just it feeds n-mosfets. The important think is two mosfet must not be on the same time.

Anyway, D6 and D5 diodes are used for current protection thats why they are connected as serial to mosfet. D7 and D8 diodes for voltage protection. They have 800V breaking voltages.

With kind regards,

Sunay

Have you looked at a flyback design? Usually flybacks are the most poular choice for low power (less than 200W) and for stepping up the voltage. They usually consist of one switching device and a small transformer. You can even get an integrated package such as power integrations TOP Switch.

Flyback devices can also generate very high voltages, certainly much higher than 400V if required.