Title:
SWITCHING REGULATOR
Document Type and Number:
Japanese Patent JPS6139853
Kind Code:
A
Abstract:
PURPOSE:To enhance the reliability by turning OFF a switching transistor by the differentiated output when a surge is inputted, thereby preventing the surge from passing to an output. CONSTITUTION:A switching regulator has a switching transistor Q, an error amplifier CMP, a pulse width modulator PWM, controls to feed back in a direction for increasing the output voltage if the output voltage V0 is lower than a set value and for decreasing the output voltage if it is higher than the set value to output a stabilized voltage V0. In this case, a differentiator GRD for differentiating an input voltage Vi is added, the output terminal of a high value priority circuit OR is connected to the input terminal of the PWM, and the output terminals of the CMP and GRD are respectively connected to the two input terminals of the OR. Thus, when a surge voltage is applied to the input, the voltage is supplied as the differentiated output Vg by the GRD to the OR, the OR selects higher one of the two inputs Vd and Vg and outputs. Thus, the surge voltage is prevented from passing to the output side by the switching of the transistor Q.
Inventors:
SHIMIZU KEIICHI
Application Number:
JP15892784A
Publication Date:
February 26, 1986
Filing Date:
July 31, 1984
Export Citation:
Assignee:
TOSHIBA ELECTRIC EQUIP
International Classes:
H02M3/155; H02M3/156; (IPC1-7): H02M3/156
Attorney, Agent or Firm:
Tatsuo Ito