Allegro says they have replaced it with the 3967 and 3977.
Have a look here:
http://www.allegromicro.com/sf/3967/They might even send you a sample.
David
derekhawkins wrote:
>Look at the bottom of that page;
>
>UCN5804B pulls
>Famous stepper motor driver integrated circuit (spec sheet available
>see our 93I002) these chips have been discontinued and are hard to
>find. We lucked onto a pile of solder pulls and they are offered here
>at a greatly reduced price. These trims have all been tested. Inquire
>about 100 lot pricing.
>25I001 Unit Price : $3.50
>
>
>