The input voltage of my system is ±15V. I need to generate the ±5V voltage. As I need it to power precise analog components (ADC, op amps), my plan is to use DC/DC converter for reducing it to, lets say ±7V, and than to use linear regulator (like LT3032) to get the required ±5V (as linear regulators in general have lower noise). As total current of my system is about 1A, I would avoid solution with only linear regulators because of substantial dissipation. However, I am not sure how to implement DC/DC conversion for negative rail. I know that there are options for supply inversion (make negative rail from positive), but it seems (maybe I am wrong) that those inversion rails circuits are usually for currents less than 1A. And those circuits only use positive rail, although I have also the negative one coming to the system.
I saw somewhere schematic with two (non-isolated) DC/DC converters, connected like in the following figure, but I am not sure if this is possible (at least work for higher currents)? Please suggest what would be the proper solution.
Thank you in advance.
Best Answer
Yes but redrawn looks like this.
simulate this circuit – Schematic created using CircuitLab
If done with 1 IC on a custom PCB it would look like 2 independent circuits with Nch for postive switches and Pch for negative.
Some are independent adjustable, others tracking single control adjustable and others fixed Buck regulators.
You can create a split rail +/-V out also with other IC's that can share 1 inductor but multiple switches inside IC.
PSU AC-DC modules are pretty Cheap to buy these days online < $0.5 to $0.1/Watt and you can get +/-5V free off your old PC MOBO or PSU