Help--need part for Waters WISP

M. D. Unson munson at
Thu Apr 3 19:56:49 EST 1997

Hi all,
We have a couple of older Waters WISP automatic sample injectors for
HPLC.  We need to replace a quad nand driver chip.  Unfortunately
since Waters has moved on to their newer and better WISP model, they
no longer stock the chip as a part (though we can buy the entire board
from them for $350!).  We are obviously hoping to find a source for the
chip itself since there is nothing else wrong with the board!
The chip was made originally by Sprague, it is part number UDN5707A.
According to Allegro Microsystems  (which bought Sprague's semi-
conductor division), the 5707A chip was replaced with a 5706A chip.
Both have since been discontinued.  Tech services at Allegro told me that
a company called Cherry Semiconductors in RI might have an equivalent
chip, but that doesn't seem to be the case.
Can any one help us source a supply of this chip?  We'll buy several if
we can get them (up to the price of a new board!).  Anyone have an old
WISP lying around that they don't want?
Please email me directly as I don't always browse this newsgroup.
Thanks in advance,
munson at
M. D. Unson
Chem/Biochem, UC San Diego

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