eem2am
Banned
10w boost converter
hello
i am doing continuous mode boost converter for LED driver:-
Vin = 8 to 17V
Vout = ~28V max
I out = 350mA
Power out = 10W.
Maximum FET Drain current is 2A.
Switching frequency = 510KHz.
PWM controller IC = LTC1871.
....Due to the potentially low input voltage , the switching mosfet will have to be a logic level FET.
The PCB that it must be built on is just 6.5cm by 1.5cm and double sided.
As you can imagine, it is crammed and there is no room for any appreciable heatsink.
-There isn't even that much copper PCB area to spare for the drain node of the FET to aid cooling.
There is no fan to cool it.
The LED board is however, MCPCB , and its screwed to a heatsink.
Considering my inability to use much of (or any of) a heatsink for the FET , what are your thoughts on using this SOT223 FET (BSP318S):-
**broken link removed**
-Or do you think the following IRLR120 D-PAK (chunkier looking) MOSFET would be better?
http://www.datasheetcatalog.org/datasheet/irf/irlr120.pdf
At this high frequency , i reckon the switching losses are going to be the decider.
So i am thinking of going for the smaller SOT223 and snubbering it to shift out some of that current and reduce the switching losses a bit.
Have readers any thoughts on a great MOSFET for this application?
hello
i am doing continuous mode boost converter for LED driver:-
Vin = 8 to 17V
Vout = ~28V max
I out = 350mA
Power out = 10W.
Maximum FET Drain current is 2A.
Switching frequency = 510KHz.
PWM controller IC = LTC1871.
....Due to the potentially low input voltage , the switching mosfet will have to be a logic level FET.
The PCB that it must be built on is just 6.5cm by 1.5cm and double sided.
As you can imagine, it is crammed and there is no room for any appreciable heatsink.
-There isn't even that much copper PCB area to spare for the drain node of the FET to aid cooling.
There is no fan to cool it.
The LED board is however, MCPCB , and its screwed to a heatsink.
Considering my inability to use much of (or any of) a heatsink for the FET , what are your thoughts on using this SOT223 FET (BSP318S):-
**broken link removed**
-Or do you think the following IRLR120 D-PAK (chunkier looking) MOSFET would be better?
http://www.datasheetcatalog.org/datasheet/irf/irlr120.pdf
At this high frequency , i reckon the switching losses are going to be the decider.
So i am thinking of going for the smaller SOT223 and snubbering it to shift out some of that current and reduce the switching losses a bit.
Have readers any thoughts on a great MOSFET for this application?