Nice work! Looks good. I could easily knock together a board design if you wish.
Originally Posted by H500 The circuit is simpler than the lmd18245 designs I looked at. |
One thing you haven't taken into account is that you're comparing a unipolar driver to a bipolar driver.
To be fair you'd need two times the amount of FETs combined in h-bridges with back-emf suppressing diodes, current sense resistors or a high-side current sense amplifier, 2 x 4 bit DACs, plus your two comparators and RC oscillators to feed the PWM. The LMD18245 attracts it's price tag because it does all this and more (thermal protection, almost lossless coil current detection) for you.
Comparing apples and oranges really..
Alan.