Buck-Boost Converter IC for 5V 3A Output from 4 Ni-Cad Batteries (4.5–5.5V Input)

Hi All,
First question so hopefully you can go easy on me!

I am trying to get a steady 5V at about 3A max to run a raspberry Pi and other peripherals.

The source is 4 Ni-Cad batteries whose output can range from say 4.5 to 5.5V depending upon charge level.

I was going to use a TL497A but from the looks of it, it will only operate as a step up OR a step down but not both from the same configuration.

Does anyone know of a power management chip that will do what im after? ...Or perhaps someone could point out where I am going wrong with my thinking?

Thanks!

For example: http://www.linear.com/parametric/Buck-Boost_Regulator or http://www.analog.com/en/power-management/swi...s-integrated-fet-switches/products/index.html . So the LTC3113 or ATP2164 (among others) would be suitable for your application. But be aware that your battery voltage might drop well below the 4.5V when drawing that much current, so better take a regulator which can work with less input voltage than 4.5V. Hope that helps.

Hi Thanks heaps!

Exactly the sort of info I was after. I will look through these and find one that has a inhibit pin that I can use with 3.3V logic as I want to boot the RPi from an interrupt from an MPU-6050 accelerometer.
Cheers Enrico!

I have used SEPIC converters for this sort of application, they are good for up to an amp or two, can be a problem to get stable on occasions, but have some other advantages over the buck/boost type of converter.