本发明提高半导体设备之电源电压之转换效率。本发明之非绝缘型DC-DC转换器系具有高侧开关用之功率MOS‧FET及低侧开关用之功率MOS‧FET串联地连接之电路者；而于同一半导体芯片5b内形成：低侧开关用之功率MOS‧FET，及并联地连接于该低侧开关用之功率MOS‧FET之萧特基障壁二极管D1。萧特基障壁二极管D1之形成区域SDR配置于半导体芯片5b之短方向之中央，于其两侧配置低侧之功率MOS‧FET之形成区域。而且从半导体芯片5b之主面之两长边附近之闸极指叉6a，朝向中央之萧特基障壁二极管D1之形成区域SDR，以夹入该形成区域SDR之方式，延伸配置复数条闸极指叉6b。

In a non-insulated DC-DC converter having a circuit in which a power MOS-FET high-side switch and a power MOS-FET low-side switch are connected in series, the power MOS-FET low-side switch and a Schottky barrier diode (D1) to be connected in parallel with the power MOS-FET low-side switch are formed within one semiconductor chip (5b). The formation region SDR of the Schottky barrier diode (D1) is disposed in the center in the shorter direction of the semiconductor chip (5b), and on both sides thereof, the formation regions of the power MOS-FET low-side switch are disposed. From the gate finger (6b) in the vicinity of both long sides on the main surface of the semiconductor chip (5b) toward the formation region SDR of the Schottky barrier diode (D1), a plurality of gate fingers (6b) are disposed so as to interpose the formation region SDR between them.