<p>In the present invention, a power supply device comprises the following: a first switching power supply circuit (2) that is configured so as to convert a first input voltage (Vi) supplied by a first input power source (1) to a desired first output voltage (Vo1) and output the first output voltage (Vo1); a second switching power supply circuit (4) that is configured so as to convert a second input voltage (Vi) supplied by a second input power source (1) to a desired second output voltage (Vo2) and output the second output voltage (Vo2); and a feedback control circuit (6) that is configured so as to control the duty ratio of a first switch (11) and a second switch (21) that should detect and adjust the current flowing through a first inductor (12) and a second inductor (22) so that the first output voltage (Vo1) and the second output voltage (Vo2) become a desired value. The feedback control circuit (6) comprises an oscillator circuit (60) that generates a sawtooth wave signal (Vt). The power supply device carries out slope compensation when adjusting the duty ratio of the first switch (11) and the second switch (21) on the basis of the sawtooth wave signal (Vt).</p>
