Title:
【発明の名称】リップルフィルタ回路
Document Type and Number:
Japanese Patent JP2547655
Kind Code:
B2
Abstract:
PURPOSE:To prevent the influence of a fluctuation from appearing in a ripple filter by providing a comparator for comparing the output voltage of a ripple filter circuit and a power supply voltage, and controlling a third transistor in the cut-off direction by the output signal of the comparator circuit at the time when the power supply voltage is dropped. CONSTITUTION:When a power supply voltage VCC is dropped, the base of a transistor Tr8 is also dropped in a certain ratio (R6/(R6+R7)). However, since a comparator part A2 is added, as for the base potentials of transistors Tr7, Tr8, when the voltage VCC of a current line is changed downward suddenly, the base potential of Tr7 becomes higher than the base potential of Tr8. Therefore, Tr7 is turned on, and also, Tr6 is turned on. Thus, since Tr3 is in the turn-off direction, it becomes a high impedance, and it can be prevented that a ripple is mixed in from the power source line VCC. Accordingly, even if the power supply voltage of the power source line is fluctuated suddenly, the fluctuation of the power source line does not appear in the ripple filter output.
Inventors:
FUJISAWA MASANORI
KOSHIZUKA SHIGEO
KOSHIZUKA SHIGEO
Application Number:
JP20325690A
Publication Date:
October 23, 1996
Filing Date:
July 31, 1990
Export Citation:
Assignee:
SANYO DENKI KK
International Classes:
H03H11/04; H02J3/01; (IPC1-7): H03H11/04; H02J3/01
Domestic Patent References:
| JP62295126A | ||||
| JP61161001A | ||||
| JP6146645U | ||||
| JP623938Y2 |
Attorney, Agent or Firm:
Kenji Yoshida (2 outside)