I need a .33 ohm resistor for a sense resistor for MC34063 regulator.

I can't find them anywhere on the Mouser site. Am I just looking in the wrong place? Where should I be looking?

 

Digikey has 13 types.

 

Why not start with 3X 1Ω resistors, and parallel them?

You can also wind your own bifilar resistor, it is not hard and uses plain wire.

 

Why not start with 3X 1Ω resistors, and parallel them?

Space. The board needs to be as small as possible.

 

Digikey has 13 types.

Thanks.

Looks like the smallest is 1/2 watt for .33. Am I missing something?

Wonder why I can't find them on mouser?

 

Take a look here
http://www2.mouser.com/Passive-Components/Resistors/Current-Sense-Resistors/_/N-7fjcf?P=1z0vijb

 

OK, so you can't parallel them, but the bifilar is a very compact option. Depending on how you wind it it can be smaller than a conventional resistor.

http://www.allaboutcircuits.com/vol_1/chpt_8/12.html

 

Mouser rates them in milliohms so search for that.
Who says there aren't any simple answers?

 

I think part of the problem with mouser is the goofy why they list values. For example they list meg ohms (mOhms) at the very top of the list. Or is that milli ohms????

 

Take a look here
http://www2.mouser.com/Passive-Components/Resistors/Current-Sense-Resistors/_/N-7fjcf?P=1z0vijb

Thanks


Is mohms actually milli ohms?? Seems a strange way to list them if so.

Looks like they have no through hole stuff at 330 mohms. But I guess if I want to practice SMD, resistors are a good way to start.

 

1/3 watt .33 Ω through hole at Digikey: 0.098" Dia x 0.256" L (2.50mm x 6.50mm), $ .57 each

http://www.digikey.com/product-detail/en/NFR2500003307JR500/PPC.33ACT-ND/614228