The switch control device controls a switching operation of a power switch. The switch control device includes an auxiliary power device. The auxiliary power device includes a parasitic capacitor, and charges the parasitic capacitor by receiving a power voltage to generate an auxiliary power voltage. The switch control device includes a control pulse generator driven by the auxiliary power voltage and generating a set pulse and a reset pulse according to an input signal that is input for controlling the switching operation of the power switch. The switch control device generates a gate signal that turns on the power switch by being synchronized with the set pulse and generates a gate signal that turns off the power switch by being synchronized with the reset pulse.