Abstract: A protection circuit includes: a high-side switch connected to a power terminal to which a predetermined power supply voltage VBB is supplied from an onboard battery; and an NMOS transistor MT1 connected to the high-side switch and configured to prevent an electrical conduction to the high-side switch when the onboard battery is reverse-connected to the power terminal, wherein a semiconductor integrated circuit is protected from a breakdown due to the reverse connection of the external power supply. A semiconductor integrated circuit apparatus includes the above-mentioned protection circuit configured to protect a semiconductor integrated circuit connected between the power terminal and the ground terminal, from an electro-static discharge breakdown. The protection circuit is connected to the clamp circuit unit inserted between the power terminal and the ground terminal, and is configured to protect the clamp circuit unit from a breakdown when the external power supply is reverse-connected.

Abstract: An oscillation circuit for generating a clock signal of a switching power supply circuit is provided. The oscillation circuit includes a circuit configured to perform frequency spreading control of the clock signal in synchronization with an output operation control signal for periodically turning on/off an output operation of the switching power supply circuit.

Abstract: An overcurrent protection circuit includes a current control part configured to control conductance of a transistor so as to limit an output current flowing when the transistor is turned on to a predetermined upper limit or less, and a duty control part configured to forcibly turning on/off the transistor at a predetermined duty ratio when a temperature protection circuit detects a temperature abnormality in a state where the current control part limits the output current.

Abstract: An apparatus for driving a light emitting device includes a constant current control circuit configured to control a current flowing through the light emitting device to be constant, and an extension circuit configured to generate a post-extending PWM signal obtained by extending a period of an input PWM signal having a first level. The constant current control circuit is turned on during the period of the post-extending PWM signal having the first level, and the constant current control circuit is turned off during a period of the post-extending PWM signal having a second level.

Abstract: An apparatus for driving a light emitting device includes a constant current control circuit configured to control a current flowing through the light emitting device to be constant, and an extension circuit configured to generate a post-extending PWM signal obtained by extending a period of an input PWM signal having a first level. The constant current control circuit is turned on during the period of the post-extending PWM signal having the first level, and the constant current control circuit is turned off during a period of the post-extending PWM signal having a second level.

Abstract: An oscillation circuit for generating a clock signal of a switching power supply circuit is provided. The oscillation circuit includes a circuit configured to perform frequency spreading control of the clock signal in synchronization with an output operation control signal for periodically turning on/off an output operation of the switching power supply circuit.