need to build a 16.1V stablized buckboost

[terramir]

I need to build a 16.1V buck boost That can handle a Voltage input anywhere from 18.5 to 9 V and current anywhere from 100 mA to 7A
is this possible to make with high efficency?
Let me know if you have a circuit
terramir

 

[terramir]

:cry: please does someone know of a buckboost circuit that could help me here?
I really need some help
terramir

 

[Sebi]

I mean, better to do this in two steps: build a boost converter with 36V output, and another buck 36V to 16.1V (L4970A from STmicro)

 

[Oznog]

Sure you can!
There's the Cuk converter, which unfortunately creates only negative voltages, so you'd probably cascade the buck/boost converters together.

Efficiency is limited. You can use a MOSFET in place of the flyback diode (if your chip supports it) and save part of the voltage drop losses there. But copper & core losses in the inductors leave you in the range of 80%-90%. Losses are lowest when when your ratio is 1:1 and gets higher from there. Unfortunately, getting losses down requires a lot of very specific knowledge of inductors and detailed specifications on the inductor core you've got, so count on the low end, maybe 70%.

I had did this with the PIC, by the way.

7 amps will require some pretty sizable inductors.