Re: need L290 substitute


Why is it whenever I find the PERFECT chip for something, it
turns out to be discontinued? I found the L290 from
SGS-Thompson, an old part that converts quadrature encoder
signals to bipolar voltage proportinal to frequency. It looks
like it could be real difficult to get this part, except from
the vultures. It is basically a double F-V converter, so it
produces a voltage proportional to count rate, with the sign of
the output indicating the direction the encoder is turning. I
think I know how to do this with 2 F-V converters and some
logic, but I can't get it below about 6 chips. Does anyone know
of a replacement for the L290 or L290B that does the same
quadrature to bipolar voltage conversion?

CPLD?

How fast do the bits change? Can you do it in software
with a PIC/AVR/8051? Pick your favorite.

--
These are my opinions, not necessarily my employer's. I hate spam.

.