In a non-insulated DC-DC converter having a circuit in which a power
MOS.cndot.FET high-side switch and a power MOS.cndot.FET low-side switch
are connected in series, the power MOS.cndot.FET low-side switch and a
Schottky barrier diode to be connected in parallel with the power
MOS.cndot.FET low-side switch are formed within one semiconductor chip.
The formation region SDR of the Schottky barrier diode is disposed in the
center in the shorter direction of the semiconductor chip, and on both
sides thereof, the formation regions of the power MOS.cndot.FET low-side
switch are disposed. From the gate finger in the vicinity of both long
sides on the main surface of the semiconductor chip toward the formation
region SDR of the Schottky barrier diode, a plurality of gate fingers are
disposed so as to interpose the formation region SDR between them.