Abstract: A video signal judgment circuit for judging the condition of a video signal compounded of a picture signal and a synchronization signal is provided. The video signal judgment circuit is adapted to first filter the video signal by a low-pass filter (LPF) having an adjustable cutoff frequency and then separate the synchronization signal from the filtered signal to provide a pulsed synchronization detection signal. Upon comparison of a detection signal formed on the basis of the synchronization detection signal with an adjustable judgment reference value, the video signal judgment circuit outputs a video signal judgment signal indicative of the condition of the video signal as to whether or not the video signal is nullified or deteriorated.

Abstract: A video signal judgment circuit for judging the condition of a video signal compounded of a picture signal and a synchronization signal is provided. The video signal judgment circuit is adapted to first filter the video signal by a low-pass filter (LPF) having an adjustable cutoff frequency and then separate the synchronization signal from the filtered signal to provide a pulsed synchronization detection signal. Upon comparison of a detection signal formed on the basis of the synchronization detection signal with an adjustable judgment reference value, the video signal judgment circuit outputs a video signal judgment signal indicative of the condition of the video signal as to whether or not the video signal is nullified or deteriorated.

Abstract: A semiconductor device includes, in first and second power source systems, electrostatic discharge (ESD) protective bonding pads connected by bonding wires to first and second power supply terminals and first and second ground terminals, first and second signal ESD protective element sections that are each connected to first and second signal bonding pads and the ESD protective bonding pads and protect first and second I/O circuits, respectively, and a power source ESD protective element section connected to first and second ESD protective bonding pads. The semiconductor device is capable of minimizing an increase in the chip size while implementing ESD damage countermeasures in which the power supply (or ground) terminal of one power source system serves as the reference potential terminal for the signal terminal of the other power source system.

Abstract: A power supply capable of making soft start efficiently. A power supply (10) is such that the time lag from the soft start trigger representing the start of soft start control to the actual soft start can be decreased by offsetting the potential of a soft start signal from the ground potential. The offset is slightly lower than the minimum potential of a triangular signal. The highest potential level of the soft start signal is preferably lower than the power supply potential.