On 2011-09-17 4:52 PM, Franc Zabkar wrote:

FWIW, Hitachi has a HA17432VLTP device with a "3B"
marking code in an MPAKV package:
http://www.datasheetarchive.com/dl/D...DSA-247658.pdf

It is designated for "industrial use".

Its pinout is K-A-Ref whereas the pinout of the HA17431VLTP device
(marking 3A) is Ref-A-K.

Specifications:
http://www.renesas.com/_full_product...ators_root.jsp

AH, I think that's it or something very close! Hitachi even
specifies that the part is intended to be used in switching
power supplies, in conjunction with an optocoupler in the
feedback circuit, so it's a very probable match.

The device on the boards I've been working on is SO-89, which
Hitachi is calling "UPAK". Any of their "U" versions of the
431 & 432 have this package, with marking codes 4A, 4B, etc.
So this is probably the same basic kind of part, but a different
manufacturer, using 3B as marking code for the SO-89 version.

Thanks for the tip!

--
Cheers,
Robbie Hatley
Stanton, CA, USA
lonewolf (at) well (dot) com
http://www.well.com/user/lonewolf/