The present disclosure presents a surge protection circuit, and a power supply device and an LED lighting device both applying the surge protection circuit. The surge protection circuit includes an inductive circuit and an energy-releasing circuit. The inductive circuit is coupled to a power loop for a load, and is configured to receive and temporarily store surge energy in the power loop. The energy-releasing circuit is connected in parallel with the inductive circuit, and is configured to release the surge energy for preventing the surge energy from affecting later-stage circuit(s).

Systems and methods herein use a sensing circuit to detect an overvoltage at a voltage node as a drain current. A current-mode comparator converts the detected current into a control signal, which is provided to a control circuit. The control circuit uses the control signal cut of a bias current to turn off switches in a protection circuit to create a high-impedance electrical path between the voltage node and the to-be-protected voltage node.

Reduced flyback electrostatic discharge (ESD) surge protection is disclosed. An ESD protection circuit differentiates ESD events from normal power on based on supply rise time. During an ESD protection cycle, the ESD protection circuit briefly clamps a supply on an identified ESD edge to limit and protect an electronic device from high voltage and/or current. In some cases, a surge condition may occur as the ESD protection circuit becomes disabled, such as in the presence of a fast rise time power supply. When the power supply is also inductive, a flyback voltage overshoot at the sudden release of the ESD clamp can result in permanent over voltage-related device damage. An exemplary ESD protection circuit includes a controlled disable state which reduces or eliminates flyback during such a surge by gradually ramping down current from the ESD protection cycle.

A circuit board with an electrostatic discharge protection mechanism and an electronic apparatus having the same are provided. The circuit board includes a substrate, at least one signal trace, and a conductive element. The at least one signal trace is disposed on the substrate. The conductive element is electrically connected to a ground plane of the substrate and crosses over the at least one signal trace. The conductive element has at least one discharging portion. The position of the at least one discharging portion corresponds to the at least one signal trace. A gap exists between the at least one discharging portion and the at least one signal trace. A static electricity of the at least one signal trace is discharged to the at least one discharging portion.

A circuit board with an electrostatic discharge protection mechanism and an electronic apparatus having the same are provided. The circuit board includes a substrate, at least one signal trace, and a conductive element. The at least one signal trace is disposed on the substrate. The conductive element is electrically connected to a ground plane of the substrate and crosses over the at least one signal trace. The conductive element has at least one discharging portion. The position of the at least one discharging portion corresponds to the at least one signal trace. A gap exists between the at least one discharging portion and the at least one signal trace. A static electricity of the at least one signal trace is discharged to the at least one discharging portion.

Reduced flyback electrostatic discharge (ESD) surge protection is disclosed. An ESD protection circuit differentiates ESD events from normal power on based on supply rise time. During an ESD protection cycle, the ESD protection circuit briefly clamps a supply on an identified ESD edge to limit and protect an electronic device from high voltage and/or current. In some cases, a surge condition may occur as the ESD protection circuit becomes disabled, such as in the presence of a fast rise time power supply. When the power supply is also inductive, a flyback voltage overshoot at the sudden release of the ESD clamp can result in permanent over voltage-related device damage. An exemplary ESD protection circuit includes a controlled disable state which reduces or eliminates flyback during such a surge by gradually ramping down current from the ESD protection cycle.

A lighting driver (600, 800, 900) receives an AC Mains voltage (15), employs a rectifier (630, 830, 930) to produce a rectified voltage, and supplies an output current (665) to a lighting device (20) in response to the rectified voltage. A surge protection circuit (840, 940) of the lighting driver includes a voltage clamping device (MOV2) connected across the output of the rectifier, and a differentiator circuit (843/845/847/849, 943/945/947/949) configured to differentiate between a temporary voltage spike at the input to the rectifier and a loss of neutral connection to the lighting driver. When a temporary voltage spike is detected, the voltage clamping device is activated to clamp the rectified voltage until the temporary voltage spike ends. When a loss of neutral is detected, the voltage clamping device is latched into a disabled state until the AC Mains voltage input to the lighting driver is turned off.

The present application proposes an over-voltage protection circuit for a USB Type-C connector. The USB Type-C connector has at least one input signal pin. The over-voltage protection circuit includes a control circuit, a voltage level shift circuit, and a system clamping circuit. The control circuit generates a control signal according to a bias voltage. The voltage level shift circuit is electrically connected to the at least one input signal pin and the control circuit, and arranged to receive the control signal and at least one input signal and the control signal from the at least one input signal pin, and regulate a voltage level of the at least one input signal according to the control signal. The system clamping circuit is electrically connected to the level shift circuit, and clamps the voltage level of the regulated input signal down to below a threshold.

The present application proposes an over-voltage protection circuit for a USB Type-C connector. The USB Type-C connector has at least one input signal pin. The over-voltage protection circuit includes a control circuit, a voltage level shift circuit, and a system clamping circuit. The control circuit generates a control signal according to a bias voltage. The voltage level shift circuit is electrically connected to the at least one input signal pin and the control circuit, and arranged to receive the control signal and at least one input signal and the control signal from the at least one input signal pin, and regulate a voltage level of the at least one input signal according to the control signal. The system clamping circuit is electrically connected to the level shift circuit, and clamps the voltage level of the regulated input signal down to below a threshold.

A crowbar circuit includes a first inductor coupled to a positive terminal of a power supply at a first terminal, and at a second terminal coupled in series with a main thyristor having a main gate drive for limiting a discharge current through main thyristor; a resistor coupled to the main thyristor at a first terminal and to the negative terminal at a second terminal; an auxiliary thyristor having an auxiliary gate drive coupled in series with a first capacitor at a first terminal and an auxiliary inductor at a second terminal, the auxiliary inductor coupled between the first terminal of the resistor and the first capacitor; a first diode couple between the first terminal of the resistor and the first terminal of the auxiliary thyristor; and a second diode coupled between the positive terminal and the negative terminal.