Could anyone suggest me a p-channel mosfet (SOT23 package)

I need to source about 8.5 V upto 3.5 amp

 

You're really pushing the limits for a P-ch MOSFET in a SOT23 package.

SI2323CDS-T1-GE3
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=SI2323CDS-T1-GE3CT-ND
Datasheet: http://www.vishay.com/docs/65700/si2323cd.pdf

 

Geese, 39 milliohms at 4.5V Vgs.

Gotta love that DK search engine!

 

Do not always believe what is written there.

Always look at the datasheet.

 

Excellent point, mik3. Added link to datasheet.

[eta]
Digikey is usually pretty good about including links to the manufacturers' datasheet, but this part was an exception.

As it was late and I was tired, I didn't bother to check if they actually linked to a mfgr's datasheet.

 

Excellent point, mik3. Added link to datasheet.

Experience!