Hi, all,
I'm doing a miniaturized version of my low noise diode laser controller for a big biomed customer. It's supposed to replace an existing unit for retrofitting, as well as being designed in to their new products.
The wrinkle is that it has to run off a single +5V supply instead of our usual +24V. Sooooo, it needs a boost converter.
To reduce the dissipation in the TEC driver, I'm going Class H there, as I mentioned in another thread, which means I also need a buck converter. Bucks and inverting buck-boost converters I've done lots of, but I've never done a positive boost before.
There's also a possibility that +5V won't be enough headroom on the Class H stage. Some TECs such as CUI's use much finer fingers and so get equivalent delta-T and heating capacity at higher voltages and lower currents. Thus I'd like to have a population option to run the buck off the output of the boost. This is of course fairly fraught, given the stability problems of boost converters running in CCM and the negative input resistance of all switchers. Also, space is at a huge premium on this board.
Advice welcome!
Cheers
Phil Hobbs