I need to convert 1Vdc to 5Vdc. I can find a lot of circuit for
bigger amounts but nothing for the little bit I want. So any help is
appreciated.
Andy
Try the
www.linear.com LT3400. It works down to 0.85 volts. The attached
LTSpice simulation shows an efficiency of 87%, driving 5 volts into 100
ohms. I don't trust the simulator so much since I got over 300% efficiency
on a previous model, but this seems about right. They claim 92% typical.
They also have an LTC3401 which runs at 3 MHz and has synchronous
rectification for up to 97% efficiency. You can try these models using the
LTC jigs.
These parts can actually produce one or two watts output.
You can get free samples direct from Linear and order small quantities.
These parts cost about $2 to $3.
Paul
===========================================================================================
Version 4
SHEET 1 2552 1624
WIRE 1696 1120 1600 1120
WIRE 1872 1120 1696 1120
WIRE 1920 1120 1872 1120
WIRE 2064 1120 2000 1120
WIRE 1600 1152 1600 1120
WIRE 1872 1184 1872 1120
WIRE 2064 1248 2064 1120
WIRE 2064 1248 2016 1248
WIRE 1600 1264 1600 1232
WIRE 1696 1328 1696 1120
WIRE 1728 1328 1696 1328
WIRE 2080 1328 2016 1328
WIRE 2240 1328 2080 1328
WIRE 2336 1328 2240 1328
WIRE 2336 1344 2336 1328
WIRE 2240 1360 2240 1328
WIRE 2080 1408 2016 1408
WIRE 2080 1424 2080 1408
WIRE 2240 1456 2240 1424
WIRE 2336 1456 2336 1424
WIRE 1872 1488 1872 1472
WIRE 2080 1520 2080 1504
FLAG 1872 1488 0
FLAG 2080 1520 0
FLAG 1600 1264 0
FLAG 2240 1456 0
FLAG 2336 1456 0
FLAG 2336 1328 OUT
FLAG 1600 1120 IN
SYMBOL POWERPRODUCTS\\LTC3400 1872 1328 R0
SYMATTR InstName U1
SYMBOL ind 1904 1136 R270
WINDOW 0 32 56 VTop 0
WINDOW 3 5 56 VBottom 0
SYMATTR InstName L1
SYMATTR Value 4.7µ
SYMATTR SpiceLine Rser=0.1
SYMBOL RES 2064 1312 R0
SYMATTR InstName R1
SYMATTR Value 1.5Meg
SYMBOL res 2064 1408 R0
SYMATTR InstName R2
SYMATTR Value 500k
SYMBOL VOLTAGE 1600 1136 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value .9
SYMBOL cap 2224 1360 R0
SYMATTR InstName C1
SYMATTR Value 4.7µ
SYMBOL res 2320 1328 R0
SYMATTR InstName Rload
SYMATTR Value 100
TEXT 2168 1504 Left 0 !.tran 500u startup
