Semiconductor device, start-up circuit having first and second circuits and a single voltage output terminal coupled to a second node between the semiconductor unit and the first circuit, and operating method for the same

An operating method for a start-up circuit, wherein the start-up circuit comprises:

• a semiconductor unit coupled to a first node and a second node;
• a first circuit, coupled between the first node and the second node, constituted by a plurality of diodes electrically connected in series and in the same direction, wherein an anode end of the first circuit is connected to the first node and a cathode end of the first circuit is connected to the second node;
• a second circuit, coupled between the first node and a ground terminal, constituted by a plurality of diodes electrically connected in series and in the same direction, wherein an anode end of the second circuit is directly connected to the ground terminal and a cathode end of the second circuit is connected to the first node;
• a voltage input terminal coupled to the semiconductor unit;
• and
• a single voltage output terminal coupled to the second node, connected directly to the cathode end of the first circuit, the operating method for the start-up circuit comprising:
• providing an input voltage to the voltage input terminal to generate an electric current flowing from the voltage input terminal, through the semiconductor unit, to the single voltage output terminal to generate an output voltage at the single voltage output terminal, wherein the single output voltage forms a reverse bias to the diodes of the first circuit and the second circuit.

A semiconductor device, comprising:

• a semiconductor unit coupled to a first node and a second node, comprising a source, a drain and a gate between the source and the drain, wherein the gate is coupled to the first node;
• a first diode element coupled between the source and the gate, wherein an anode end of the first diode element is connected to the gate and a cathode end of the first diode element is connected to the source;
• a second diode element, coupled to the gate and the first circuit, wherein an anode end of the second diode element is directly connected to a ground terminal and a cathode end of the second diode element is connected to the first node;
• and
• a single voltage output terminal coupled to the second node between the source and the first diode element, and connected directly to the cathode end of the first diode element and for providing a voltage forming a reverse bias to the first diode element and the second diode element, wherein the first diode element and the second diode element respectively have a plurality of diodes electrically connected in series and in the same direction.