Abstract: An LED lighting circuit mounted in a lighting device having LEDs as a light source, the circuit including: a light emitting unit that includes a plurality of LED circuits for supplying drive currents to a plurality of LEDs connected in series or parallel; a failure detection unit that detects whether each of the drive currents flowing through the plurality of LED circuits is equal to or larger than a predetermined fault current value for those LED circuits as a whole; and a failure alert unit that performs a predetermined alert operation if the failure alert unit detects that at least one of the drive currents is equal to or larger than the predetermined fault current value.

Abstract: A test circuit with which the cost for checking the duty ratio of a clock signal is restrained. A sampling timing generating circuit, to which the measurement-target clock signal MCK is input, outputs first and second sampling trigger signals to A sample-and-hold circuit 102 respective prescribed timings before and after a timing that is one-half period of the measurement-target clock signal after a first edge of the measurement-target clock signal. The sample-and-hold circuit samples and holds the measurement-target clock signal in correspondence with respective ones of the first and second sampling trigger signals. The sample-and-hold circuit forms all or part of a scan path and outputs a signal, which is being held for checking the duty ratio, from a scan output terminal in response to a scan clock signal.

Abstract: An input circuit according to an embodiment of the present invention includes: a comparator circuit comparing a reference voltage with an input voltage; a resistor element provided between a power supply line supplying a power supply voltage of the comparator circuit and an input line applied with the input voltage; and a transmitting circuit transmitting a potential change of the power supply line to a reference voltage supply line supplying the reference voltage.