The LM2705 is a micropower step-up DC-DC converter in a small 5-pin SOT-23 package. A current-limited, fixed-off-time control scheme conserves operating current, which results in high efficiency over a wide range of load conditions. The 21-V switch allows for output voltages as high as 20 V. The low 400-ns off-time permits the use of tiny, low-profile inductors and capacitors to minimize footprint and cost in space-conscious portable applications. The LM2705 is ideal for LCD panels requiring low current and high efficiency as well as white-LED applications for cellular phone back-lighting. The LM2705 device can drive up to 3 white LEDs from a single Li-Ion battery. The low peak-inductor current of the LM2705 makes it ideal for USB applications. For all available packages, see the orderable addendum at the end of the data sheet.