Title:
SWITCHING POWER-SUPPLY CIRCUIT
Document Type and Number:
Japanese Patent JP2715921
Kind Code:
B2
Abstract:
PURPOSE: To obtain a switching power-supply circuit in which a loss caused by the operating delay of a MOS5ET for synchronous rectification with reference to the operation of a main switch is reduced to a minimum under various input conditions and various load conditions in a switching power supply which uses the MOSFET for a rectifying operation.
CONSTITUTION: Control-signal levels V0 to V2 which correspond to an output voltage generated by a control circuit 26 and triangular waves V3 are level- compared by respective comparators 19 to 22, and respective switching elements 3 to 5 are ON-OFF-controlled by using respective comparison output pulses P0 to P2.At this time, the control-signal level V1 is level-shifted sequentially by constant values (VCE,1, VCE2) by means of transistors 12, 13 in a saturated state, and the control-signal levels V0, V2 are generated. Since the control-signal levels V0, V2 are level-shifted by the constant values with reference to the control-signal level 1, the dead time in an ON-OFF-operation of the switching elements 3, 4, 5 can be maintained constant irrespective of an input/output condition.
Inventors:
Yousuke Shinada
Nao Hamamura
Nao Hamamura
Application Number:
JP17497294A
Publication Date:
February 18, 1998
Filing Date:
July 27, 1994
Export Citation:
Assignee:
NEC
International Classes:
H02M3/28; G05F1/613; H02M3/335; (IPC1-7): H02M3/28
Domestic Patent References:
| JP759340A | ||||
| JP4150777A | ||||
| JP4127869A | ||||
| JP63124767A | ||||
| JP62104477A |
Attorney, Agent or Firm:
Yanagi Kawa Shin