The second feedback pin FB2 may be used for mode selection. FIG. 4 is a circuit diagram showing an example configuration of a mode selector 130. The mode selector 130 includes resistors R31 and R32 arranged between the FB2 pin and the ground, a switch SW31, and a comparator CMP31. During a judgment period immediately after the startup of the power management circuit 100, the switch SW31 is turned on. After the judgment, the switch SW3 is turned off. This arrangement is capable of preventing wasted current from flowing via the resistors R31 and R32.

With an application (system) to be set to the first mode MODE1, the FB2 pin is coupled to the output capacitor Co2 directly or via a resistive voltage dividing circuit. When the mode is judged, the output voltage V_OUT2 is zero, and accordingly, the voltage V_FB2 applied to the FB2 pin is zero. Accordingly, the comparator CMP31 judges that V_FB2<V_TH. In this case, a mode signal MODE is set to a level (e.g., high level) that indicates the first mode.

With an application (system) to be set to the second mode MODE2, the FB2 pin is set such that it is pulled up to a high-level voltage (e.g., power supply voltage on the order of 5 V or other voltages) via a resistor R33. In the mode judgment operation, the switch SW31 is turned on. In this state, a voltage that is proportional to the high-level voltage of 5 V is input to the comparator CMP31. As a result, the comparator CMP31 judges that V_FB2>V_TH. In this case, the mode signal MODE is set to a level (e.g., low level) that indicates the second mode.