I'm currently working on a simple but beefy DC-DC converter, that takes 12VDC and outputs 0-12VDC. It's intended to be part of a modular bench supply, so the minimum load current is unknown, but it's specified for up to 10A out yet should be able to sustain 10mA loads without too much ripple.

Here's my specifications (they are flexible):

12VDC in, 0-12VDC out

Output load 0-10A

Switching freq 100kHz

Current ripple: 20%

Voltage ripple: 1%

Synchronous rectifier topology, so forward losses are around 0.1V

So here's the question: If I design for 10A load, my calculator tells me to use a 15uH inductor. But if I lower the current, that value *increases* proportionally. I can find 10A, 15uH inductors, but not 10A, 1500uH inductors. What do I choose, and what kind of ill effects can I expect if I use the lower-value inductor with lower load currents? Does the larger output capacitor compensate well enough, at least when operating in constant-voltage mode?