Check out IR2153. It's a bootstrapped halfbridge driver with the
oscillator built in, so we can lose the 555. $1.68 at Digi-Key. It
also has an internal 15.6V zener so the PNP and zener in my circuit
would go away too. MOSFET IRFZ48V is $1.05 ea. Not as good as
the one you chose, but it'd work OK here at .012 ohms. I'll bet
we're still under $5 for the whole works. I do like the idea of
losing the shottkey.

On Sat, 27 Nov 2004 03:06:32 -0500, Spehro Pefhany
wrote:

A more expensive (almost double), but still very simple method could
use two MOSFETs (losing the Schottky and gaining some efficiency), an
ST L6384 bootstrapped half-bridge driver, 2 n-channel HRF3205's (0.008
ohms/$2.20 ea) and a 50% duty cycle 555 as previously.