Question for Electronic Masters. LT1581

[Barbarin]

Just a second before making definetively the production boards,direct drive 3 and 7 LSIII.. What do you think about the mentioned linear regulator. Batt packs are 3,6V NiMH.
At 10 Amp dropout is almost 0,5V, but at 3 Amps is below 0,2V. Quite good and interesting, specially if using J binned Luxeons. Two of them will work nice on the 7x Luxeon board.

http://www.linear.com/pdf/158125fa.pdf


Ideas, suggestion?

 

[Doug S]

[ QUOTE ]
barbarin said:
Ideas, suggestion?

[/ QUOTE ]
Why yes. Read the third sentance of the "Description" section of the datasheet carefully. /ubbthreads/images/graemlins/smile.gif

 

[evan9162]

Looks like it needs that extra 1V to run the main pass transistor (looking at the block diagram on page 5).

 

[MrAl]

Hello there,

Yes, i have to agree...it wont work connected directly.

To run off of 3.6 volts an idea would be to build up
a simply switched capacitor boost circuit -- an ic
and a few caps -- to supply the extra 1v or so to
the 'Control' input. This supply only has to put out about
10ma or so if you intend to run the main output up to say
1 amp.

Hey if you build this up now you gotta tell us how
well it worked :-)

Take care,
Al