boostconverterdc/dc converterdualpower supply
I'm doing a project with a Silicon Photo-multiplayer where the breakdown voltage when negatively biased is -25V. I was wondering is there anyway to connect two DC to DC boost converters to give me a virtual ground and positive and negative rails. I was looking at converters such as these.
I have access to a dual power supply but for reasons of portability it is not suitable. Thanks.
A
In principle, you can make inverted buck converter; however, this will be difficult in real life since suitable parts are rare. You may want to try a different approach; generate negative output from the same positive input using inverting or Cuk converter topology. Read Jim Willams' "Switching Regulators for Poets" -> http://cds.linear.com/docs/en/application-note/an25fa.pdf if you desire more elegant solution.
Costs a GPIO pin, but simple.
simulate this circuit – Schematic created using CircuitLab
Make sure the MOSFET you choose is rated for the 2.5A continuous,has a logic level gate and a low Rds on. Pull the gate low after Vout stabilizes. If that part had a power good output, you could even tie the power good signal to the gate.
Best Answer
You can boost to +25V and +50V, then use +25V as a virtual ground. But why not buck-boost to -25V? Almost any normal buck would do the job.