A boost apparatus including a boost power conversion circuit and a control chip is provided. The boost power conversion circuit is configured to receive a DC input voltage and provide a DC output voltage to a light-emitting-diode (LED) load in response to a pulse-width-modulation (PWM) signal. The control chip has a first complex function pin, and is configured to: generate the PWM signal to control the operation of the boost power conversion circuit; perform an OCP detection on the boost power conversion circuit through the first complex function pin when the PWM signal is enabled to determine whether to activate an OCP mechanism; and perform an OVP detection on the boost power conversion circuit through the first complex function pin when the PWM signal is disabled to determine whether to activate an OVP mechanism.