Power switch devices and methods are provided where an undervoltage event in a supply voltage is detected. Information regarding the undervoltage event is stored in a memory element. The memory element is supplied by a control signal.

A delay-time correction circuit delays an input signal for generating a pre-drive signal to a drive unit generating a drive signal. A transition-change sensor senses a transition change in one of a turn-on operation and turn-off operation. A correction-signal generator generates a correction signal in response to the transition change sensed by the transition-change sensor and to the input signal. A delay output unit generates an output signal corresponding to the pre-drive signal by delaying the input signal using the correction signal. The delay output unit delays the output signal that instructs the other of a turn-on operation and turn-off operation, from the input signal, in accordance with a length of a period for the transition change in the one of a turn-on operation and turn-off operation that is performed immediately before the other of a turn-on operation and turn-off operation.

A delay-time correction circuit delays an input signal for generating a pre-drive signal to a drive unit generating a drive signal. A transition-change sensor senses a transition change in one of a turn-on operation and turn-off operation. A correction-signal generator generates a correction signal in response to the transition change sensed by the transition-change sensor and to the input signal. A delay output unit generates an output signal corresponding to the pre-drive signal by delaying the input signal using the correction signal. The delay output unit delays the output signal that instructs the other of a turn-on operation and turn-off operation, from the input signal, in accordance with a length of a period for the transition change in the one of a turn-on operation and turn-off operation that is performed immediately before the other of a turn-on operation and turn-off operation.

An integrated processing unit is supplied by a power supply voltage present at the terminals of a capacitor configured to supply a maximum permissible voltage drop. A periodic pulse signal is generated having a period that is less than or equal to a current period determined from the maximum permissible voltage drop and a current consumption of the processing unit. The power supply voltage is compared with a threshold voltage at the pulse rate of the periodic pulse signal. A control signal generated from that comparison is delivered to the processing unit and has a first value when the power supply voltage is greater than or equal to the threshold voltage and a second value when the power supply voltage is less than the threshold voltage.

An integrated processing unit is supplied by a power supply voltage present at the terminals of a capacitor configured to supply a maximum permissible voltage drop. A periodic pulse signal is generated having a period that is less than or equal to a current period determined from the maximum permissible voltage drop and a current consumption of the processing unit. The power supply voltage is compared with a threshold voltage at the pulse rate of the periodic pulse signal. A control signal generated from that comparison is delivered to the processing unit and has a first value when the power supply voltage is greater than or equal to the threshold voltage and a second value when the power supply voltage is less than the threshold voltage.

A motor controller includes a rectifier for converting AC power supplied from an AC power supply into DC power and outputting the DC power; an AC voltage detector for detecting an AC voltage value of the AC power supply and outputting the AC voltage value as a detection value; a power failure detector for determining that a power failure is occurring, when a state in which the outputted detection value is equal to or lower than a regulation voltage has continued for a regulation time or more; and a power failure detection condition determiner for determining or modifying the regulation time.

A power supply circuit includes an internal power source that receives power supply from an external power source, an abnormality detection circuit that receives power supply from the internal power source to detect abnormalities of the external power source, a protection target circuit that receives the power supply from the external power source, and a protection function unit that restricts electric power supplied to the protection target circuit to a predetermined range, when the abnormality detection circuit detects the abnormalities.

A power supply circuit includes an internal power source that receives power supply from an external power source, an abnormality detection circuit that receives power supply from the internal power source to detect abnormalities of the external power source, a protection target circuit that receives the power supply from the external power source, and a protection function unit that restricts electric power supplied to the protection target circuit to a predetermined range, when the abnormality detection circuit detects the abnormalities.

A technique for managing undervoltage in a compute system is disclosed. The technique includes a method that further includes: detecting an AC undervoltage condition in the compute system; and upon detecting the AC undervoltage condition: dynamically determining a holdup time as a function of the present load; determining a monitoring period as a function of the dynamically determined holdup time; waiting for the determined monitoring period to expire; and upon expiration of the determined monitoring period, perform a shutdown process if the AC undervoltage condition persists.

A technique for managing undervoltage in a compute system is disclosed. The technique includes a method that further includes: detecting an AC undervoltage condition in the compute system; and upon detecting the AC undervoltage condition: dynamically determining a holdup time as a function of the present load; determining a monitoring period as a function of the dynamically determined holdup time; waiting for the determined monitoring period to expire; and upon expiration of the determined monitoring period, perform a shutdown process if the AC undervoltage condition persists.