A quick flick through the datasheet suggests that this would be easy
enough to do if you wanted to do it properly. Motor current capability
of the IC is modest - under 2A at <=3D 40V I think. A single high side P
Channel MOSFET in the common VMA/VMB feed would allow supply
sequencing. Effects of inductive load can be designed for. I'd suspect
that the cheap and nasty drivers fail because they are not prepared to
design properly.

TB6560
$6/1.
$2.60/10000
$487.50 callout fee, travel, tax, dinner, E&OE, YMMV.

Suitable MOSFT (there will be cheaper).
$1.45 /1
About $0.050/1000
Prices:      http://search.digikey.com/us/en/products/IRFU5410PBF/IRFU5410P=
BF-ND/812416
Data:  http://www.irf.com/product-info/datasheets/data/irfr5410pbf.pdf

DPak.


Russell
--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.