5V from mains

Can anyone point me in the right direction ? I saw a chip that does this a
long time ago, but can't remember what/where...
TIA

 

Web search "off line switcher". Or "smoke".

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google? See http://cfaj.freeshell.org/google/

 

: Can anyone point me in the right direction ? I saw a chip that does this a
: long time ago, but can't remember what/where...
: TIA
AFAIR the 5V were not isolated from the mains. Perhaps thats not what you
want.

 

Does it have to be a chip? They make 5V switching wall warts now that are
so small they fit inside the mains plug, you can't even really call it a
"wart" any more.

 

Harris semiconductor did the chip that he probably saw, but I don't think
Intersil now do it, it seemed to disappear a while ago. These are ideal
for specific things, such as powering logic circuits inside mains
equipment, where insulation/isolation is provided elsewhere. However for
any application where this is not the case, the minature wall wart
approach is a lot safer. It also simplifies getting approvals, so unless
the production 'run' is large, may well be the better solution. For a non
isolated supply, inside a piece of equipment, the PowerIntegrations
LNK304, is the current popular choice. It is used inside many things like
lamp dimmer assemblies.

Best Wishes