| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power supply circuit that attains a relatively high power supply voltage even with a low received power when generating power for an internal circuit by rectifying electromagnetic waves given from outside. <P>SOLUTION: A diode-connected DMOS 5 and an NMOS 6 are connected in series between a node N1 at an end of a resonant circuit comprising a coil 1 and a capacitor 2 and a ground potential GND. A gate of the NMOS 6 is connected to a node N2 where a power supply voltage VCL is output. When this causes the power supply voltage VCL accumulated in a capacitor 3 to exceed a threshold voltage VTN of the NMOS 6, the NMOS 6 becomes consistently kept in an on state, performing half wave rectification by the diode-connected DMOS 5. Since the DMOS 5 has the low absolute value of threshold voltage, the voltage drop in conduction is small, thereby attaining a higher power supply voltage VCL. <P>COPYRIGHT: (C)2010,JPO&INPIT |
