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From: "Nucharin W. Jansen"
Subject: Re: Mike, I tried UCC3941-5 but it didn't work..
Date: Sat, 09 Nov 2002 21:33:49 +0700
Organization: C.S. Communications Co. Ltd.
References: <3DCB3046.5E796622@fanwap.com> <3DCC625A.27A11DFA@earthlink.net>
NNTP-Posting-Date: Sat, 9 Nov 2002 14:33:52 +0000 (UTC)
X-Mailer: Mozilla 4.8 [en] (Windows NT 5.0; U)
> > Mike, I saw your old article. I agree that the pinout are awkward.
> > Today I tried UCC3941-5 and it didn't work.
> > I just got 2v out from 1 cell ni-cd ( 1.3v )
> > VDG got only ~5v.
> > I didn't use 10uF and 10v zener diode connect to VDG.
> > Is these wrong ?
> > I use a small inductor ( look like green resistor color ).
> > I hate TI and UNITRODE datasheet.
> > Btw, MAX761 and MAX757 work well for me.
> > I looking for another high power IC ( 1 cell boost converter ).
> > TL499A step up at 40 -50 mA @ 3.6v
> > Tong/.
> > -------------
> > Subject: Re: Voltage "tripler"
> > View: Complete Thread (21 articles)
> > Original Format
> > Newsgroups: sci.electronics.design
> > Date: 2001-04-18 00:25:52 PST
> > > > > TI has a very useful DC-DC boost chip designed for exactly this purpose. The
> > > > > UC3941 will work from .8v to 3v and boost it up to 6v at 100mA. I've used
> > > > > tham and found them nice and stable but sensitive to layout and the pinout
> > > > > locations are awkward. As to the $5 part, that's what Digikey charges for
> > > > > single units, dropping to $3 at 100 units. Plus it needs 3 small caps, 2
> > > > > resistors, a coil and a schottky diode.
> > > > >
> > > > > Mike
> > > > >
> > > > >
> > > > > > Could anybody give me suggestions for a circuit that will roughly triple the
> > > > > > input voltage, according to the following specifications:
> > > > > >
> > > > > > - Cost: Less than $5 for parts
> > > > > > - Input Voltage: 1.00..1.4 V DC
> > > > > > - Output Voltage: 3.6..4.0V DC
> > > > > > - Output Current: >= 30mA
> > > > > > - Quiescent Current: <= 20uA
> Seems to me that if you do not follow the datasheet recommendations,
> that one *should* expect problems.....
TI and Unitrode datasheet doesn't include some information always.
I don't know minimum current for Feedback Pin. ( UCC3914-ADJ )
So, I tried to test UCC3914-5 fix output 5v.
These IC has 2 outputs. A normal and 9v output ( VGD ).
I will try again. I just brought 10v zener diode and 1uF capacitor.
BTW, TI is great! with fastest sample IC ship via UPS.
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