Isolated converter and led driver using the isolated converter

• Main Authors: Wernars, Johannes Petrus, Hong, Liang, Fang, Yuhong, Premraj, Ashwin, Clauberg, Bernd, Li, Ming
• Format: Patent
• Language: English
• Published: 25.04.2023
• Subjects: ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY

An isolated converter has a transformer with a primary winding (in a primary side circuit) and a secondary winding magnetically coupled to the primary winding. A first Y-capacitor is electrically connected between the primary side circuit and the secondary winding. The detection circuit is for detecting information at the primary side, preferably information about the input supply received at the input, and more preferably the information is that whether the input supply is an alternating current (AC) supply or a direct current (DC) supply, and the detection circuit includes the first Y-capacitor. The detection circuit enables the detected information to be provided directly to a secondary side controller, without needing opto-isolators or other isolated data transmission. The detection circuit (20) comprises a capacitor divider comprising the first Y-capacitor (C5), and further comprising a second impedance and a third capacitor (C7) connected in series with the first Y-capacitor (C5), with the first Y-capacitor (C1), the second impedance, and the third capacitors (C5, C6, C7) in series between a primary side ground (PGND) and the input (12), wherein the detection circuit is for detecting a voltage across a second impedance to obtain a signal indicating the information at the primary side. Preferably the second impedance comprises a second capacitor (C6).