Hello,
I want to add to my device a DC-DC buck converter that has a wide range input from approximately 10-30VDC with an output of 12V fixed. However, because the input is a battery and the voltage might drop (as stated from 10-30), my buck converter will stop bucking. i was looking for an ic that has a bypass mode but did not find one for this input range. so i decided to look into designing one myself, can anyone help me with some ideas?
Thanks...

 

How about a Buck-Boost Converter?

If not then ...
Will your bypass device use a MOSFET or Relay ?
Sense the Low Battery Voltage and then switch your bypass device ON.
Use hysteresis to prevent chatter

 

i forgot to mention i have a target price and limited components. a buck boost converter will cost me more than 3 dollars.

 

Hello,

Have a look at the MAX15004/15005
4.5V to 40V Input Automotive
Flyback/Boost/SEPIC Power-Supply Controllers

Bertus

 

How about a Buck-Boost Converter?

If not then ...
Will your bypass device use a MOSFET or Relay ?
Sense the Low Battery Voltage and then switch your bypass device ON.
Use hysteresis to prevent chatter

I just want to add a baypass circuit on my buck converter, am still looking for reliable circuit designs and cheap.