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.

A switching regulator includes a power stage circuit and a control circuit. The power stage circuit operates a high-side switch and a low-side switch therein according to a high-side signal and a low-side signal respectively to generate an inductor current flowing through an inductor therein. The adjustment signal generation circuit in the control circuit generates an adjustment level according to the high-side signal, the low-side signal, and/or the inductor current, wherein the adjustment level is switched between a reverse recovery level and an anti-latch-up level, and is electrically connected to a low-side isolation region of the low-side switch. The reverse recovery level is lower than the input voltage. The anti-latch-up level is higher than the reverse recovery level to avoid a latch-up effect.

A switching regulator includes a power stage circuit and a control circuit. The power stage circuit operates a high-side switch and a low-side switch therein according to a high-side signal and a low-side signal respectively to generate an inductor current flowing through an inductor therein. The adjustment signal generation circuit in the control circuit generates an adjustment level according to the high-side signal, the low-side signal, and/or the inductor current, wherein the adjustment level is switched between a reverse recovery level and an anti-latch-up level, and is electrically connected to a low-side isolation region of the low-side switch. The reverse recovery level is lower than the input voltage. The anti-latch-up level is higher than the reverse recovery level to avoid a latch-up effect.

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.

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.

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.

Protection circuits, USB interface integrated circuits, and methods for protecting host circuitry from USB port pin overvoltages, in which a switch is connected between a USB port pin and a middle node, and a detection circuit compares the middle node voltage with a reference voltage. A control circuit turns off the switch and turns on a clamp circuit to conduct pull down current from the middle node in response to the middle node voltage exceeding the reference voltage to mitigate overvoltage conditions on a host pin coupled to the middle node. When the middle node voltage falls below the reference voltage, the control circuit delays for a predetermined time and then turns off the clamp circuit and turns on the switch.

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.

This electrostatic protection circuit makes it possible for a discharge operation to be started only in the case where a rise in an applied voltage is steep, and for static electricity to be sufficiently released. This electrostatic protection circuit includes a discharge circuit that is connected between a first node and a second node and discharges charge produced by static electricity, a latch circuit that is connected between the first node and the second node and outputs a signal that controls operation of the discharge circuit to the discharge circuit, a switch circuit that is connected to the latch circuit and changes the signal that controls operation of the discharge circuit, and a control circuit that is connected between the first node and the second node and outputs a signal that controls operation of the switch circuit to the switch circuit.