Lpc2000

----- Original Message ----- 
From: "Xtian Xultz" <xultz@...>
To: <lpc2000@yahoogroups.com>
Sent: Wednesday, April 26, 2006 3:45 PM
Subject: Re: [lpc2000] 2103 forces dual supply?


> Em Ter 25 Abr 2006 20:55, Robert Adsett escreveu:
>> At 08:04 PM 4/25/2006 -0300, Xtian Xultz wrote:
>> >  Its too dangerous to generate 1.8V (more or less) from the 3.3V with 
>> > two
>> >diodes in series?
>> >Someone tryed this?
>>
>> Just put in an LDO.  You can get them as small as a sot23 giving you 
>> about
>> 90mA with a 30C rise dropping down from the 3V3 supply.
>>
>> Robert
>
> Thats what I am using, LM317 with SOT23 footprint. What makes me sad is 
> that
> both regulators (one for 3,3 and one for 1,8V) plus the resistors ocuppies
> more space on the board than the LPC itself. So, LPC is a really small
> microcontroller (looking for a ARM based wich has only 48 pins, the
> concorrents are 100 or 144 pins, the smallers!) and with a very small
> footprint (soldering 20 mils pins with soldering iron its not easy, I am
> doing, but its not funny. Its interesting that a 25 mils chip is much more
> easy to solder and to design the board) but the power circuit is bigger...

There is a tiny little Maxim dual regulator (MAX8882) in SOT23-6 giving 1.8 
V and 3.3 V. They used only to be available by the reel, but one can buy 
small quantities, now.

Leon
--
Leon Heller, G1HSM
leon.heller@...
http://www.geocities.com/leon_heller 

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