US Patent No. 9,860,945

DIGITALLY-CONTROLLED SWITCH-MODE START-UP CIRCUIT FOR LED-BASED LIGHTS


Patent No. 9,860,945
Issue Date January 02, 2018
Title Digitally-controlled Switch-mode Start-up Circuit For Led-based Lights
Inventorship Erik J. Mentze, Austin, TX (US)
Karl Thompson, Converse, TX (US)
Assignee PHILIPS LIGHTING HOLDING B.V., Eindhoven (NL)

Claim of US Patent No. 9,860,945

1. An apparatus, comprising:
a voltage regulator configured to provide an output voltage for operating a lighting controller;
a power FET coupled to the voltage regulator and configured to provide a supply current to the voltage regulator from a line
input;

a gate drive circuit coupled to a gate of the power FET and configured to operate the power FET as a switching-mode power
supply during a start-up mode and period of the lighting controller;

a digital control loop configured to:
monitor an auxiliary output voltage node coupled to a source of the power FET; and after a first threshold voltage is reached
by the monitored output voltage, control the gate drive circuit to couple the gate of the power FET to ground; and

wherein the digital control loop is further configured to after a second threshold voltage is reached by the monitored output
voltage, control the gate drive circuit to couple the gate of the power FET to a supply voltage node.