Abstract: In a redundant configuration with multiple power sources connected in parallel to enhance reliability, a power source in which an overvoltage failure occurred has been difficult to identify and unable to be deactivated, which has impeded the improvement of reliability. However, it has become possible to deactivate selectively only the power source in which an overvoltage failure has occurred, by providing a independency-discrimination circuit that identifies the occurrence of the overvoltage failure by use of the state of a parallel operation control circuit, and connecting the independency-discrimination circuit, an overvoltage detection circuit, and a connection circuit.

Abstract: The invention relates to an ESD protection with ability to enhance trigger-on speed of a low voltage Triggered PNP (LVTPNP) unit for protecting internal circuits of an integrated circuit from attack of an ESD stress. The ESD protection unit incorporates either detection circuit or power clamp circuit to efficiently trigger on a trigger node as a heavily doped region of LVTPNP devices among an I/O pad, a VDD pin and a VSS pin. As soon as the trigger node of each LVTPNP device receives a trigger signal from either the ESD detection circuit or power clamp circuit, the threshold voltage of the LVTPNP devices are capable of being therefore reduced to enhance trigger-on speed of the LVTPNP devices that discharge ESD current.

Abstract: A surge protector for alternating current service includes at least an incoming hot line and a neutral line, but usually includes an incoming hot line, an incoming neutral line and a safety ground line. The surge protector has an input transformer and a series connected transformer with input connection to the input transformer secondary winding, and connected in series to a non-linear surge suppression circuit, and therefore has a gross output connection to the non-linear surge suppression circuit, and a low impedance input to the secondary winding of the series connected transformer from the non-linear surge suppression circuit, and has a surge cancelled hot line output connection.