| 摘要 |
PURPOSE:To enable detecting a load current, even if a circuit is in a reflux mode, by connecting a current-sensing MOS transistor in parallel with a current- monitoring MOS transistor and by preventing a reverse current from flowing through said current-monitoring MOS transistor. CONSTITUTION:When N-channel MOS transistor 4 is in the ON state, a current flowing through a load is equal to the total of drain currents of N-channel MOS transistors 2 and 3, and the drain current of said N-channel MOS transistor 3 can be monitored with a sense voltage VS generated in a sense resistor 9. When the N-channel MOS transistor 4 is turned OFF, the current flows through the sense resistor 9 because the body of sense FET 3, 6 is connected with VGND via diode. Thus, a load current can be detected, even after the N- channel MOSFET 4 changes in the OFF state. |
