Setting up an HIP4081A - components needed

Hi,

I would like to drive four AUIRS8409-7P in an H-bridge configuration with an HIP4081A controlled with an arduino with pwm.

I want to order it and the mosfet from canada.newark. I want to be sure to buy everything at once or at least the most components possible.

I know I need diodes and capacitor for the bootstrap on high side, some resistor and I dont really know what else I need. I'm looking at the "Typical Application" drawing on the datasheet of the HIP4081A.

For now, in my cart I have:

-4x mosfet AUIRFS8409-7P (datasheet) -1x mosfet driver HIP4081A(datasheet) -A few 1n4002 diode. I chose them because they were cheap and I think that any small diode can do the trick, but I'm maybe wrong. I guess the backward current is important? (datasheet) -A few tantalum capacitor 1uF. Here I really do know what capacitance I should get or what to look for for a the capacitor. Please correct me for the capacitor. (datasheet)

That is for now, I will edit the post when needed. I know there is some resistor, but I have no clue for their Ohm value.

I dont have a oscilloscope on hand, should it be a good a idea to buy a cheap one like this one. It's a small DIY kit, extremely basic but cheap.

Thank you very much, I know I make a lot of post but I really need your help. Bernard

1N4002 is not suitable, you must use a schottky or ultra fast rectifier for the bootstrapping diodes. 1N4002 takes 2us for reverse recovery which is too long unless you aren't using PWM at all.

Ceramic for decoupling caps won't explode on overvoltage spikes - tantalum are again unsuitable for this sort of circuit and a real fire risk here.

bootstrap caps need to be 10 to 20x the gate capacitance, 12V decoupling cap(s) 10 to 20x the bootstrap caps - its a heirarchy of charge storage. MLCC ceramic caps are low inductance and low resistance and the sort do use.

All the traces in the bootstrap current path need to be short and wide (low inductance) and enclose as little area as possible (low inductance).

This AN is invaluable BTW: http://www.intersil.com/content/dam/Intersil/documents/an94/an9405.pdf

All of which is to say is "yes, if the utmost in performance is expected" - though with an application short of that then maybe not so much. So, short of that, the thing won't utterly fail, go/no-go, for falling short in regard to some jot or tittle. But a guy not knowing so much isn't going to get all of that nailed down anyway. Sometimes this stuff isn't about Q&A'ing a thing to death, you really need to know (or have a good idea of) what you're doing.

http://www.rambal.com/descargas/libros/Nuts%20and%20Volts/2/Stamp%20Controlled%20High%20Power%20H-Bridge.pdf

Don't mind the "stamp controlled" part (it is a side issue, not essential.)

If you skimp on the layout or bootstrap/decoupling components don't be surprised if the MOSFETs pop. They do not tolerate overvoltage on the gate and you need to keep the gate drive supply tightly constrained. In my experience its extremely easy to pop MOSFETs in this sort of circuit if you aren't careful about all the details. An oscilloscope is really really useful when commissioning such a circuit to check for any nasty transients getting in the wrong places.

The issue is the massive transients flying around when a big MOSFET switches (dV/dt in the 10^8 V/s or higher range, dI/dt similar so stray inductance cannot be ignored). You can use gate resistors to slow down the transitions but that limits the max PWM frequency. If not using PWM you can make life easy by larger gate resistors to slow down the switching transients. With PWM fast switching is required to keep losses under control, and the higher the power of the bridge the more important fast switching is.

One useful bit of protection circuitry is having something like 15V or 16V zeners across every FET's gate-source terminals right at the MOSFET leads. Lower voltage zeners will swamp the HIP4081's charge pump, higher will allow the voltages to exceed 20V limit. Note the main MOSFETs are 0.00055 ohms, I'm judging very high powers are involved.

MarkT: 1N4002 is not suitable, you must use a schottky or ultra fast rectifier for the bootstrapping diodes. 1N4002 takes 2us for reverse recovery which is too long unless you aren't using PWM at all.

Ceramic for decoupling caps won't explode on overvoltage spikes - tantalum are again unsuitable for this sort of circuit and a real fire risk here.

bootstrap caps need to be 10 to 20x the gate capacitance, 12V decoupling cap(s) 10 to 20x the bootstrap caps - its a heirarchy of charge storage. MLCC ceramic caps are low inductance and low resistance and the sort do use.

All the traces in the bootstrap current path need to be short and wide (low inductance) and enclose as little area as possible (low inductance).

This AN is invaluable BTW: http://www.intersil.com/content/dam/Intersil/documents/an94/an9405.pdf

Thanks you MarkT,

MCMLR50V224KX7R CERAMIC CAPACITOR, another capacitor, 0.22uF, which make a ration of about 15x the mosfet capacitance. This capacitor is rated 50v, is this this a problem? I dont really see any capacitor in the 12v range.

For the diode, this MUR115G, which has a 25ns reverse recovery time.

Now I see there is some resistor on the HDEL and LDEL pin, I think the value of the resistor has something to do with the delay for the anti shoot-through. I don't know what value to use, but in your link, MarkT, they use some 500k for some test.

I don't know if a gate resistor is a good idea, because reducing the switching speed will only lead to high temperature. And I guess it's not good.

Correct me if i'm wrong on anything please

[quote author=Runaway Pancake date=1437615410 link=msg=2326563] All of which is to say is "yes, if the utmost in performance is expected" - though with an application short of that then maybe not so much. So, short of that, the thing won't utterly fail, go/no-go, for falling short in regard to some jot or tittle. But a guy not knowing so much isn't going to get all of that nailed down anyway. Sometimes this stuff isn't about Q&A'ing a thing to death, you really need to know (or have a good idea of) what you're doing.

http://www.rambal.com/descargas/libros/Nuts%20and%20Volts/2/Stamp%20Controlled%20High%20Power%20H-Bridge.pdf

Don't mind the "stamp controlled" part (it is a side issue, not essential.) [/quote]

Thanks, but the link is dead

Would a low voltage fet with 14nF gate capacitance be a good match for a high voltage drive IC.
I see values of 100mA/1nF in the HIP4081A datasheet.

I think OP had choosen a 9Amp drve IC in another post.
Leo…

Wawa:
Would a low voltage fet with 14nF gate capacitance be a good match for a high voltage drive IC.
I see values of 100mA/1nF in the HIP4081A datasheet.

I think OP had choosen a 9Amp drve IC in another post.
Leo…

I’m not sure what is your point here… Can you explain?

MarkT’s advice is spot on. Exactly what I would have cautioned, and he’s absolutely correct, you will be hard pressed to identify problems without a 'scope.

You didn’t give much info about voltage and current required, so we can’t really give your component selection a grade.

My personal rule of thumb is to size the fet’s free-wheeling diodes (if used) at roughly 1/4 of the h-bridge current. Sometimes using the parasitic diode as the catcher leads to a high stored charge which can often be worked around by using fast(er) recovery diodes in parallel. If it’s low enough voltage, a Schottky can be used. In higher voltages >40V there are other tricks.