What stepper IC controller do you use?

Select the IC you would or have used in your DIY stepper motor controller board.

I used the LMD18200 part because it can drive 3A continuous. Also use the Keling motors. Many of the NEMA23C motors require 2.8A or 3.0A, whereas many of the driver chips are only able to deliver 2.5A.

currently constructing a driver for bipolar stepper motors (3A) using LMD18245

Youy forgot an option for discrete drivers.... :)

Currently working on a PIC based system with discrete FET output stage capable of 8A at upto 80V in bipolar mode with upto 32 microstep mode. Based upon the drive circuit Microchip publish on their site. Just about got all the components together to take this forward.

Now I have four "Mardus-Kreutz" boards (unipolar 8A 80Volt discrete components, microstep modes Full, 1/2, 1/4/,1/8, 1/5, 1/10, 1/16.

I am working on a 5A 48V Bipolar microstepper 4 axis board with the same microstep characteristics.

built my own with gecko 201's and 54 volt supply,geckos are my choice

What what I'm learning is that most NEMA 23+ motors will need arround a 4 amp controller. Along as the board and provide this, there haven't been too much say or biased towards one controller vs another. davidmb: I thought about this too, but I'm thinking of opting buying my first controllers cards, then improve upon them once i have the experience to know what is the pro's and cons of a certain configuration. I also have considered in using USB laser mouses to use as motion tracking as they are cheap and very accurate. ( but that's for another discussions :p )

Well I bought some Keilling 425 oz/in motors and there very nice weight, can't wait to get them fired up!

Right now I have used an Intersil HIP-4081A at 80V @ 2.5A with good luck but now I am running my 495oz in bipolar stepper motors at 86VDC using a design I did to get around the 80V limit of most commercial drivers.
1) My 2 H Bridges are each made up using 4ea IRFB33N15D TO-220 PKG 150V FETS driven by 2ea NSC LM5109 Drivers.
2) My power supply is a Toroid Transformer from AnTek that after my bridge rectifier & 2ea 15,000uF 100V 105 degree caps delivers a perfect 86VDC @ 6A plus a 98VDC @ 1A output. This is done by adding thier 12V winding to the top of the 2 32V windings that are also put in series.
3) The 98VDC is used to power my Series Pass Regulator Circuit made up using a TO-220 HUF75842P3 150V 43A .042 ohm RDSon FET & a TL431 Shunt Regulator. The regulator to work correctly needs a minimum of 5V more then the voltage on the fet's drain. So to get a regulated 86VDC output at 6A using a .042 ohm RDSon FET we must have right at 88VDC but 87.4V works fine also. So by adding the 12V winding to the other windings I got the headroom I needed though a 6V winding would have worked.
4) This setup controlled from a ATMEGA mpu chip provides me with 1, 1/2, 1/4, 1/8, 1/12 stepping & by using it's internal ADC the H-Bridge Current converted to a voltage can be read & controlled perfectly.
5) My design will work to 100VDC but my newer upgrade to this design has me changing out the LM5109 for a LM5104 which allows for Deadtime programming. This makes it all the much better.

Now for those who want to upgrade or update a driver design that doesn't work above lets say 50VDC there is a way to add a P-Channel FET to the N-Channels being used in the H-Bridge thus allowing a higher voltage to be switched to the stepper motor. Since once the N-Channel turns on it pulls the gate of the P-Channel to ground thus turning it fully on. This does require a discreet H-Bridge design as all 4 fets high side & low side must now be setup to turn on the P-Channel hence on the high side the Drain is run thru a resister to Vcc with the Source grounded & the P-Channel's gate attached to the N channel's Drain. On the Low side a resister is added from the Drain to Vcc with again the P-Channels Gate being attached to the drain.

Note: I have been able to alter the timing from a Unipolar design then do my P-Channel mods to all 4 of the pull to ground N-Channel Fets. All 4 of the N-Chan FETS must have a P-Chan FET attached else the turn on / off timing will be off. But remember that the P-Channels with the ability to do this well cost a bit more then just making up your own design with driver chips from NSC.

SLA7024 and LB1845

No, not really my choice but where I'm at they come free from old Epson printers.

Do they work? the LB1845 did wiggle a bit and made some strange hiss, the SLA7024 just sat motionless.

I use MCR1207 hybrid for the unipolar stepper motors.

Right now we use AC servo motor and driver from www.gskcnc.cn only, for it is more accurate and prices is as cheap as stepper.