To provide an inexpensive boot-strap type switching power supply circuit which stably performs power feeding to a circuit for driving a switching element even at light loading.
The switching power supply circuit comprises: the switching element 1; a boot strap circuit having a boot-strapping capacitor C1 connected to a source of the switching element 1 at its one end; the drive circuit 4 which generates a drive signal fed to a gate of the switching element by using a boot strap voltage VB outputted from the boot strap circuit; a voltage controlling DMOS 5 arranged between the source of the switching element 1 and the ground; and a current limit part (including a voltage detecting DMOS 6, a voltage detecting NMOS 7, a voltage detecting resistor 8, a comparator 11, and a DMOS driver 9) for limiting a current flowing in the voltage controlling DMOS 5.
IKUTA YOSHINORI
JP2007068269A | 2007-03-15 | |||
JP2002281744A | 2002-09-27 | |||
JP2005304210A | 2005-10-27 |
Inoue On
Kazutoshi Shibuya
Next Patent: DC GROUND-FAULT DETECTION DEVICE AND MULTIPLEX DC POWER SUPPLY CIRCUIT