I'm trying to get the most of the instantaneous power available from a lithium primary cell and, as it stands now, the efficiency is proving to be a bit of a roadblock. Like the person who made this post: e2e.ti.com/.../824651, I'm getting efficiency numbers closer to the mid-60's rather than the mid-80's that I would expect (e.g. for approx. 380 - 400mW output in the 100-150mA range, I'm getting input currents of around 240mA at 2.5V).
For a quick overview of the system: the inductor I'm using is the HTEK16080H-1R0MSR, which seems to fits the device requirements, and I have the device in Power Save mode, but where I think I might be running into trouble is the way I'm using it. Instead of a standard constant voltage source, I'm using it at a constant current source with the feedback coming from the conditioned output of an amplifier, which is measuring current with a small (100mOhm) sense resistor. There is an analog switch in the current path, but I'm measuring no more than ~80mV across it and the current sense resistor combined. The parasitic resistance in the rest of the circuit is negligible (<1Ohm).
Is this part simply not suitable for this application or is there some other factor I should consider/change?
Thanks,
Tyler