VEHICLE LAMP AND LIGHTING CIRCUIT

A lighting circuit of a semiconductor light source includes a light control circuit and a constant current circuit. The light control circuit is configured to generate a pulsed light control signal having a duty ratio corresponding to the input pulse signal and having at least one edge softened in each pulse. The constant current circuit includes a linear regulator. The constant current circuit is configured to stabilize a lamp current flowing into the semiconductor light source to a target amount corresponding to the light control signal.