> >A very simple and cheap gate driver is as per attached gif.

> I would be very tempted to use Microchips gate drive chips.
> MCP1401/2 inverting/non-inverting gate driver in SOT23-5 package
> 500mA drive capability.

The temptation may be easy to resist :-).
Digikey know not of the product, nor do the other 20 sellers at 
www.findchips.com :-(

The products sound useful if minimum component count is desired but 
performance wise they sound about as capable as the simple circuit I 
posted. It's not "my circuit" -  it has been around auld lang syne and 
it may even have been used by Noah for his FET drivers on the Ark's 
ventillator motors (of which he probably had quite a few).

Microchip show samples (of the IC, not of Noah's cct) and you can 
follow the "buy online now" link to a putative Indian seller, but if 
you don't log in it's not obvious who the seller is.

Microchip show budgetary price as $US0.44 in volume and, as the 
circuit as proposed would ideally have two of these that's probably 
$US1 in moderate volumes for drivers alone.

Given Mahit's general comments about pricing and what he could obtain 
where he lives, I suspect that my sub $US0.10 solution (possibly 
little more than that for two of them) may prove attractive.

The discrete circuit does not have, as shown, some of the specs of the 
uChip parts but it would be very satisfactory in this application. 
I've used it as shown for 20 kHz 8 bit PWM Addition of a speedup 
capacitor alone increases bandwidth into the low MHz region. Output 
voltage range is limited only by the transistors used and drive 
current capability can be "butal" if you want it to be. (For "brutal" 
you'll need to up the transistors from the BC337/BC327 I usually use).
As is 500 mA is easy. Input levels are by design. Logic input will 
withstand whatever voltage the diode is rated at that you put on the 
input if you choose to put one there :-). Otherwise still quite a lot.

The capacitive drive rise times are essentially another way of stating 
the current drive capabilities and 34nS to raise 1000 pF to 10V say is 
equivalent to about 340 mA constant current so is consistent with the 
500 mA drive claim.


        Russell


> MCP1401/2 inverting/non-inverting gate driver in SOT23-5 package
> 500mA drive capability.
> logic level input.
> output supply range 4.5-18V
> high capacitive load drive capability - 470pF in 19nS, 1000pF in 
> 34nS (typ)
> matched rise and fall times.
> latch-up protected, will withstand 500mA reverse current on output.
> logic input will withstand negative swing to -5V

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