TI Is unhelpful, and their Datasheet is HORRIBLE! Please help!

I've got a uc3770an stepper motor driver controller.
Their data sheet gives me a phase pin. This pin is the only input out of the three that do ANYTHING! Anyone have a clue what the others do!?

what do you want it to do? do you understand principle of driving stepper motor?

quick look at schematic in the datasheet tells that this is a single full bridge which can be used to drive one of the two stepper motor coils.
to run one motor you need two chips and that gives you two phases you need to control speed and direction of one stepper motor.

Yes I understand the principle
I have had the chips running a stepper motor already but I have no idea what the other two input pins are. I asked at TI I even phoned and the engineers didn't even want to try because they had no idea.
There is no clear explanation on what the two pins do but when I connect them on the chips to power or ground nothing happens. It would be really awesome to get the thing to work fully because right now the steppers have minimal torque and can barely spin against the stress of my finger touching it.
(I did know about the two chips to run it, I have it all setup right now with a PIC but if you have ideas I can test them with an Arduino)

What made you choose that IC in the first place?

They were free samples from TI and I wanted some drivers for a cool project I am doing. If it was successful I was going to order a dozen of them.

I agree that the datasheet for the UC3770 is pretty thin.

However, there is a reference on it's product page and datasheet to the UC3717, and that datasheet has much more to offer. Including a test and application circuit showing how to make use of the current sense comparators controlled by the 'other two pins' you are asking about. See figures 6 and 12.

https://www.ti.com/lit/ds/symlink/uc3717a.pdf

The datasheet for the UC3770 was written in 2000 and comes from the Unitrode Corporation. That was taken over around then by TI. (Details).

The UC3770A is an enhancement of the UC3717, also made by Unitrode, and it seems that the datasheet for the UC3770 is written in a way that expects knowledge of the UC3717.

It doesn't look as though any changes have been made to these products or the data sheets in the last decade. I suspect that none of these have been made recently, and that TI are just packaging IC dies that they got from Unitrode.

Hey, Thanks for the datasheet! That has way more information and I actually know what the pins do
I'll try and hook it up later today, Ill be back if I have anymore problems.
Thanks