| 摘要 |
PURPOSE:To unnecessitate a gate bias circuit even in the ON state, and realize the saving of power and the preventing of an accident of service interruption, by using a device having a nonvolatile memory function, in the main body of a power MOSFET or its bias circuit. CONSTITUTION:When the source 3 of a high power MOSFET Q1 acting as a main switch is grounded, a drain 4 is connected to a load terminal, and a gate 5 is connected to the floating gate terminal 6 of a MOSFET Q2 having function of electrically rewritable nonvolatile memory. A second gate terminal 8 of Q2 is grounded, a drain terminal 7 is connected to a bias circuit. By electric charge stored in the floating gate terminal 6 of Q2, the gate terminal 5 of Q1 is biased, and Q1 turns ON. Once Q1 turns ON, the ON state of Q1 is maintained, even if the bias circuit connected to the terminal 7 of Q2 is eliminated, if only charge stored in the terminal 6 is kept. On the contrary, in the case of making Q1 turn ON, the terminal 7 is reverse-biased. |
