Re: Using a uC for DC-DC conversion?

From: Dave VanHorn (dvanhorn_at_cedar.net)
Date: 10/14/04 

Date: Thu, 14 Oct 2004 00:56:56 -0500

> That's the king size edition. I never had anything that could run above
> 12MHz. Everything else was out of the $$$ range.

Remember the CPU clock is 8 MHz.

> This would be the leather seats that I usually can't use. Any uC with a
> decent ADC on board I saw was over $2 in qties.

$1.44 in 100's from Digikey

>>That's where I've had the least problems. (none!) ...
>>
> Probably you were the HW designer and also did the firmware. Then it's
> under your control. It can become challenging when you are asked to join
> the uC party as an additional tenant.

Yes, I was :)

> It's not just batteries, electrolytic capacitors can also put on quite a
> pyrotechnic show. Wonder where fireworks were invented ;-)

Well, I do find the formula that Jim Williams gives, to be quite useful.

> You can prevent saturation on the ol' bipolar transistors with a Schottky
> or other pulldown when the collector goes below base. But the beta still
> puts a damper on things if you want to do the whole switching with that
> one transistor.

Yeah, in this case the driver was a cheap and easy solution. 

-- 
KC6ETE  Dave's Engineering Page, www.dvanhorn.org
Microcontroller Consultant, specializing in Atmel AVR