SLVAF68 July 2021 TPS61086
A practical approach to create a negative output voltage with a larger (more negative) amplitude from a negative input voltage using the TPS61086 is proposed in this application report. As it has been confirmed with the actual application case (VIN =-2.9 V~-6.0 V, VOUT =-12 V, L=3.3uH) by PSpice simulation and experimental results, the solution operates properly. The ground of TPS61086 is not connected directly to the system ground with the new configuration. In this case, the sensing point for the feedback is not direct from the actual load since the feedback voltage always needs to be referenced to the ground of the TPS61086, and the new configuration should be carefully reviewed in terms of voltage ratings, current waveforms, the feedback path, PCB layout and so on to get the desired results.