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DPRG: PowerTrends 7805 switching regulator replacement

Subject: DPRG: PowerTrends 7805 switching regulator replacement
From: Kipton Moravec kmoravec at airmail.net
Date: Fri Jan 16 08:36:45 CST 1998

David Beckham wrote:
> 
> Kipton Moravec wrote:
> >
> > Jim Brown wrote:
> > >
> > > Have yall seen these drop in switching regulator replacements for
> > > the 78xx series?
> > >
> > > They're a little bigger, it is pinout compatible (input, common, output),
> > > they're about 85% efficient, plus, they're rated for 1.5a.
> > >
> > > http://www.powertrends.com/pages/pt78st1.html
> > >
> > > The part numbers go like 78st1xx where they're equivalent to 78xx parts.
> > >
> > > For example, the 78st105 is equivalent to the 7805.
> > > 78st112 is equivalent to the 7812.
> > >
> > > It says it _requires_ a 100uf cap, but I guess power supply designs
> > > should have a hefty cap anyway.
> > >
> > > Anyone off hand know of the street price, or who has them?
> >
> > Nu Horizons Electronics Corp, 2081 Hutton Drive, Carrollton, TX, (214)
> > 488-2255 is the local distributer.  http://www.nuhorizons.com/  I will
> > call Genie tomorrow and get a price and availability number.  I just
> > happen to be in the market for a 1.2 Amp 5V power supply.
> >
> > Regards,
> > Kip
> 
> I ordered a sample from their website today, and was informed that the 5
> volt unit needs a minimum of 9 volts in (up to 36 or so).  The
> implication was they need 4 volts headroom to operate.  Not necessarily
> a problem, but something to be aware of, since the 7805 doesn't need
> that much.

Interesting.  I have the PowerTrends Data Book and both 1.5 A versions
the 78SR105 and the 78ST105 (for fast transient response) say 7 - 30 VDC
input voltage.  But the web site says 9 - 38 VDC. Go figure.  

The 78HT205 2.0 Amp version says 7 - 28 VDC in the data book.

I just spoke to Geanie at Nu Horizons.  

78SR105V - $15.35 each qty 10
78ST105V - $15.35 each qty 10

They have them in stock, which means they can deliver in about two days.

Regards,
Kip

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