Boost converter with a 2 A switch and selectable frequency
The Texas Instruments TPS61085PW is a step-up (boost) DC-DC converter built around a 2 A integrated switch, covering input voltages from 2.3 V to 6 V and delivering an adjustable output up to 18.5 V. A single logic pin selects the switching frequency — 650 kHz or 1.2 MHz — letting the designer optimise between inductor size and conversion efficiency without changing the controller.
Switching frequency trade-off and inductor selection
At 1.2 MHz the converter can use a physically smaller inductor — a real advantage when board area is tight — but the higher switching losses reduce efficiency at light loads compared to the 650 kHz setting. The 2 A switch current rating is the ceiling for the peak inductor current; the actual output current depends on the input-to-output voltage ratio and the chosen frequency, so the designer must derate for the target load.