[ASK] Converting typical Buck switcher into split rail power supply

[BravoV]

Just curious if is it that simple to make a typical Buck switcher to generate positive and negative rails using this method ? Any other considerations ?

TIA

Edit : Some corrections

[Paul Price]

No.

If the circuit you show is very lightly loaded both the Virtual-Ground and V+ outputs would have about the same output voltage refereced to V-Negative.

[chris_leyson]

You could also us a single switch in a combined SEPIC and Cuk converter, see Analog Devices app note AN-1106. http://www.analog.com/media/en/technical-documentation/application-notes/AN-1106.pdf Another option is a "flybuck" converter and wire up the coupled inductor to the negative rail, a word of warning though the rail generated by the coupled inductor has NO short circuit protection.

[BravoV]

No.

If the circuit you show is very lightly loaded both the Virtual-Ground and V+ outputs would have about the same output voltage refereced to V-Negative.

Are you saying the V-Ground and V+ must be loaded all the time, or both rails V+ "and" V- must be loaded at the same time and all the time ?

I got the idea after reading TI's app note -> SLVA369A - Creating a Split-Rail Power Supply With a Wide Input Voltage Buck Regulator , and thinking if I can apply the example like this one below at "other" buck switcher ?

[BravoV]

You could also us a single switch in a combined SEPIC and Cuk converter, see Analog Devices app note AN-1106. http://www.analog.com/media/en/technical-documentation/application-notes/AN-1106.pdf Another option is a "flybuck" converter and wire up the coupled inductor to the negative rail, a word of warning though the rail generated by the coupled inductor has NO short circuit protection.

Thanks Chris, never read that b4, noted on the short circuit weakness.