Hi,
Many of my projects (and products) use boost converters, and on the occasions I have needed an extra higher voltage, low current rail I've just used a charge pump on the switch node, like getting 9V from a 2v - 5V boost for example. One could use a coupled inductor to get higher outputs for devices with limited switch node voltage, but neither solution provides short circuit protection. In standard boosts, the input goes through the inductor and diode to output. With a charge pump it goes through an extra two diodes. Assuming these are all schottky you'll get ~ 3x 0.3 = ~0.9 drop, so even a single alkaline AA has enough current to take these out when the output is shorted for longer than a second.
Using a coupled inductor with a boost for a flyback could provide the same output as a single inductor but how would the converter react with its output shorted? I guess that question should really be - how does a flyback boost converter react to having its output shorted? Obviously with this there is no longer a direct path from input to output, I'm assuming the peak current limiting of the boost converter would determine the input current. Might be a relatively easy way of preventing damage for when the design can't prevent the output being shorted.
This isn't some specific project, just thinking of methods to add inherent short circuit protection to boost converters without relying on it being built into devices. For example the MCP1640 is a synchronous boost and claims to have short circuit protection since the output MOSFET is controlled, but the datasheet doesn't provide details of what exactly happens. Whether it resets, or just maxes out the peak inductor current or what.
I've noticed that coupled inductors with different ratios than the standard 1:1 are becoming more available (and cheaper) so it looks like a more viable option when multiple voltages are required or isolation, or short circuit protection.