I need a circuit to convert 4.8 volts from four AA rechargeable batteries to 3.7 to replace the li-ion battery in my circuit. I was thinking of using a step-down converter IC but didn't know where to start. I need chip that is DIP.

 

Or I need a boost converter to convert 2.4 volts to 3.7 (two sets of AA rechargeables.

 

Hello,

Did you already have a look at this page:
http://www.maxim-ic.com/cookbook/powersupply/

This link was also named in the useful websites thread.
http://forum.allaboutcircuits.com/showthread.php?t=9538

Greetings,
Bertus