Question about IC connections (UDN2917EB - stepper controler)

[enginenear]

Hello,
I'm a little bit confused with the diagram provided in the datasheet of this IC:

1) On page 1, under maximum ratings, it says: Pin 5 "E1 - Output emmitter voltage"... 1.0 V
Is this a voltage I need to supply, or an output? what exactly is this pin doing?

2) What is the function of SENSE(4), Vref(44), and ENABLE(42)?

Furthermore: I know that the input "PHASE" controls the direction of the current through each coil, but where is the input to actually energize each coil? ie: where do i connect my parallel port outputs, to make the controller send 'steps'?

Thanks,

 

[enginenear]

really? nobody?

 

[vonsproken]

Hi, I will try to help.

E1 (pin 5) and E2 (pin 19) go down to ground (0V), a resistor can be tied between these pins and ground to also limit current. I'm guessing the 1V is the voltage drop through the transistors.

Enable (Pin 2 and pin 42) These are used to enable it to work, tie these down to ground.

Your phase is what you connect to driver to say which way you send your current through the coils, look at the truth table on page 2 to see which way the current travels. I have a question, what are you driving? a bipolar stepper motor, this is important for me to know.

Pin 4 sense can be used to sense the current going through the circuit, this is only if you use a resistor between E1/E2 and ground.

I think you need more of an expert to answer your question about the other pins and to confirm what I say.