US Patent No. 10,263,532

MULTIPLE POWER SOURCES FOR A SWITCHING POWER CONVERTER CONTROLLER


Patent No. 10,263,532
Issue Date April 16, 2019
Title Multiple Power Sources For A Switching Power Converter Controller
Inventorship John L. Melanson, Austin, TX (US)
Eric J. King, Dripping Springs, TX (US)
Assignee SIGNIFY HOLDING B.V., Eindhoven (NL)

Claim of US Patent No. 10,263,532

1. An apparatus comprising:a first power supply having a first source follower transistor to conduct a start-up current for a controller and supply an operating voltage for the controller; and
a second power supply having a second source follower transistor to conduct a steady-state operational current for the controller and supply an operating voltage from a supply node for the controller, wherein a source of the first source follower transistor and a source of the second source follower transistor are coupled to the supply node and, during operation of the apparatus, when the source of the second source follower transistor is biased with the operating voltage at the supply node to cause the second source follower transistor to turn ON, the second source follower transistor changes the operating voltage and the change in the operating voltage at the supply node causes the first source follower transistor to automatically turn OFF.