Re: [CAD_CAM_EDM_DRO] Geckodrive asking for user input

Hi Mariss,
I am sure a +5vdc to +3.3vdc interface would not be
hard to make so the new gecko's would be able to work
for any machine. In addition a +3.3vdc to +5vdc
interface would be nice.
Michael

--- Mariss Freimanis <mariss92705@...> wrote:

> 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
>
>
>
>
>