US 12,438,469 B2
Switched-mode power supply having coupled step-down converter stages
Alexander Moser, Werl (DE); and Thomas Sprink, Salzkotten (DE)
Assigned to Phoenix Contact GmbH & Co. KG, Blomberg (DE)
Appl. No. 17/311,083
Filed by Phoenix Contact GmbH & Co. KG, Blomberg (DE)
PCT Filed Nov. 18, 2019, PCT No. PCT/EP2019/081624
§ 371(c)(1), (2) Date Nov. 10, 2021,
PCT Pub. No. WO2020/114758, PCT Pub. Date Jun. 11, 2020.
Claims priority of application No. 2018/5855 (BE), filed on Dec. 5, 2018.
Prior Publication US 2022/0181979 A1, Jun. 9, 2022
Int. Cl. H02M 3/335 (2006.01); H02M 1/00 (2006.01); H02M 3/158 (2006.01)
CPC H02M 3/33569 (2013.01) [H02M 1/0074 (2021.05); H02M 1/0077 (2021.05); H02M 3/158 (2013.01); H02M 1/007 (2021.05)] 12 Claims
OG exemplary drawing
 
1. A switched-mode power supply, comprising:
an input circuit powered by an input voltage, wherein the input voltage is based on a voltage difference between a positive input voltage and a negative input voltage;
an output circuit coupled to the input circuit and configured to provide an output voltage; and
a direct current (DC) isolating element between the input circuit and the output circuit and configured to observe a prescribed safety requirement with regard to isolation between the input voltage and the output voltage,
wherein the input circuit comprises two coupled step-down converter stages, wherein the two coupled step-down converter stages comprise a first step-down converter stage configured to step down the positive input voltage and a second step-down converter stage configured to step down the negative input voltage, wherein the two coupled step-down converter stages are connected to the input circuit upstream of the DC isolating element,
wherein the two coupled step-down converter stages are configured to cause a voltage drop in the input voltage and thus reduce an isolation voltage across the DC isolating element,
wherein the two coupled step-down converter stages are coupled to one another on an output side via an output capacitor,
wherein a coil of the first step-down converter stage and a coil of the second step-down converter stage are wound on and coupled via a common core,
wherein the two coupled step-down converter stages are configured to be controlled jointly via a control signal,
wherein the input circuit comprises a control circuit configured to generate the control signal, and
wherein a reference potential of the control circuit is associated with a center tap between the two coupled step-down converter stages.