US 11,689,097 B2
High-voltage to low-voltage interface in power converter circuit
Wen Chuen Liu, Santa Clara, CA (US); Xugang Ke, Milpitas, CA (US); Min Chen, Fremont, CA (US); and Wei Gu, San Jose, CA (US)
Assigned to Analog Devices, Inc., Wilmington, MA (US)
Filed by Analog Devices, Inc., Wilmington, MA (US)
Filed on May 5, 2021, as Appl. No. 17/308,517.
Prior Publication US 2022/0360165 A1, Nov. 10, 2022
Int. Cl. H02M 3/335 (2006.01); H02M 1/36 (2007.01)
CPC H02M 1/36 (2013.01) [H02M 3/33507 (2013.01)] 15 Claims
OG exemplary drawing
 
10. An interface circuit to couple an input voltage in a first voltage domain to a controller of a power converter circuit in a second voltage domain, the interface circuit comprising:
a depletion-mode transistor having a gate terminal, a source terminal, a drain terminal, and a substrate terminal, wherein the substrate terminal is connected to a ground potential;
a start-up circuit including:
a current limiter circuit having an input coupled to with a terminal of a high-voltage transistor, the current limiter circuit having an output coupled to with and provide an input voltage to an input of the controller of the power converter circuit; and
a first shunt regulator circuit having an input coupled to with the terminal of the high-voltage transistor, the first shunt regulator circuit to maintain a first voltage at the terminal of the high-voltage transistor; and
a line voltage detection circuit to sense a current proportional to a line voltage, the line voltage detection circuit including:
a second shunt regulator circuit having an input coupled to with the terminal of the high-voltage transistor, the second shunt regulator circuit to maintain a second voltage at the terminal of the high-voltage transistor, the second voltage lower than the first voltage.