EEVblog Electronics Community Forum

Electronics => Projects, Designs, and Technical Stuff => Topic started by: groksteve on January 06, 2021, 10:08:43 pm

Title: Gate driver IC for many, many power MOSFETs
Post by: groksteve on January 06, 2021, 10:08:43 pm

I'm working on a circuit that will use a MCU to switch many (>40) power MOSFETs at 60kHz.

Does anyone know of a gate driver IC with many channels so that I can minimize the number of parts? I'd really prefer to not have one driver IC per transistor if possible.
I've seen that there are several dual driver parts but when I look at the 4 or 8 driver versions they are almost always tailored to a specific purpose like motor driver or PMIC.

Thanks for any input!

Title: Re: Gate driver IC for many, many power MOSFETs
Post by: T3sl4co1l on January 07, 2021, 12:32:11 am

I suppose you could go to ~1.17 parts/FET with a CMOS inverter/buffer plus complementary emitter follower (get a dual transistor type).   Maybe if you have a bus driver with just enough voltage and current for the purpose.

Not really going to be any better, any other way, besides the proper dual drivers, or the specials.

Anyway, you need a resistor per gate, maybe a diode and another resistor (for asymmetrical drive), and a few bypass caps.  Adding one more part to the total isn't a huuuuge deal (but, still, is added assembly cost).

*Shrug*, 40 channels is 40 channels, it's not going to be cheap any way you cut it.  What application do you have, that doesn't fit any of the standard solutions?

Do you really have that many, on a common ground?  Just how "common" will it really be, with that much switching going on?  I guess these aren't small currents, since they need drivers.  Will you need level shifters/translators/isolators to get the gate signals up to the drivers, too? :-//

Tim

Title: Re: Gate driver IC for many, many power MOSFETs
Post by: groksteve on January 07, 2021, 01:41:28 am

Thanks for the reply!
That's what I was thinking, expensive.

The application is independently controlling >40 ignition systems based on flyback transformers.
I don't have control over the transformer end of things. The requirements are that I deliver a 4V/2A signal with 60kHz 95% duty cycle to each of the igniters.
Could you suggest another approach that might work better with the same level of control?


Cheers

Title: Re: Gate driver IC for many, many power MOSFETs
Post by: SilverSolder on January 07, 2021, 02:43:10 am

How long does the signal have to be active for?

Title: Re: Gate driver IC for many, many power MOSFETs
Post by: groksteve on January 07, 2021, 04:03:22 am

400ms minimum, ideally 550ms

Title: Re: Gate driver IC for many, many power MOSFETs
Post by: viperidae on January 07, 2021, 05:45:45 am

If you only need 4V at 2A, I'm sure there are a bunch of logic level MOSFETs you can choose from that won't require a driver.