公开(公告)号：US20170359872A1

公开(公告)日：2017-12-14

申请号：US15688082

申请日：2017-08-28

Applicant: PHILIPS LIGHTING HOLDING B.V.

Inventor： ERIK J. MENTZE ,  KARL THOMPSON

IPC: H05B33/08 ,  H02M1/36 ,  H05B37/00 ,  H02M1/00

CPC classification number: H05B33/0815 ,  H02M1/36 ,  H02M2001/0045 ,  H05B33/0812 ,  H05B33/0845 ,  H05B33/0851 ,  H05B33/0887 ,  H05B37/00

Abstract: Power consumption in a start-up circuit for a LED-based light bulb may be reduced by digitally switching a transistor of the start-up circuit coupled to the input voltage. When the transistor is digitally switched between on and off, a reduced amount of power is dissipated by the transistor, because it may not enter a saturation region of operation where the resistance of the transistor between drain and source terminals increases. The transistor may be coupled to a voltage regulator for generating one or more output voltages, including a supply voltage for a host controller IC. The transistor may be switched on and off by a digital signal generated by logic circuitry, which may decide to switch the transistor on and off based on a voltage level at an output of the voltage regulator.