Geckodrive asking for user input

Hi,

I'm cross-posting this everywhere because I need a lot of replies
fast.

I'm nearly done with a G201/G210/G202/G212 replacement design called
the G203 for right now. It is a complete, clean-sheet CPLD based new
circuit. Same size and pinout as the G201 drive but a whole lot of
new features.

Here's where I need input. The G203 uses 3.3V logic which makes the
step/direction opto-solator interface require much lower current. The
quandry:

1) Be 100% backwards compatible with the existing drives. That means
supplying +5VDC to the COMMON terminal and require 5VDC
step/direction signal levels. The G203 would keep an unplug and
replace compatibility with our current drives.

2) Change the COMMON terminal spec from +5VDC to GND. The G203
requires only 2mA max to operate step/direction optos instead of
16mA. The G203 has a max step pulse frequency of 350kHz (>10,000 RPM
on a 1.8-degree motor) without any funny G201 step/direction timing
restrictions.

The result is supply step, direction and PC ground to the G203 and it
will run. It will work now with 3.3V or 5V logic; no level-shifting
breakout boards are required, no +5VDC supplies.

Please let me know: Option (1) or option (2). The first 1,000 boards
must go to the PCB fabrification house Monday.


Mariss