The inductor would store and return most of the energy. Your control circuit would only supply the rest - adding flexibility and taking out any temperature drifts.
Farnell stocks "power chokes" in that ball park
offers 68mH - you'd need three in series - and can take 600mA. They are intended to be used "current compensated" for mains filtering, so it's not a slam dunk, but might be worth thinking about.
Le Fri, 31 May 2013 12:29:50 -0400, Phil Hobbs a écrit:
Nice chip, but that one is a false synchronous buck. It has a comparator to detect inductor current reversal and then open the bottom switch. This makes for a buck with a zero drop wheeling diode which won't work for your app.
A self oscillating half bridge driver IR25603, a dual MOS and an opamp should do the trick.
Right, one of those HV 555s I was teasing John and Bill about a couple of months back. ;)
The CTO at the customer is an ME who has done a very creditable job of picking up circuit design as he went along, so I expect that a single-chip solution would give him more of a warm fuzzy feeling about doing their own piezo controller. However, saving 98% of the cost of the current purchased parts will probably be pretty compelling even so.
Cheers
Phil Hobbs
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