Title:
PNPN SWITCH CIRCUIT
Document Type and Number:
Japanese Patent JPS5890825
Kind Code:
A
Abstract:
PURPOSE: To obtain a PNPN switch excellent in noise resistance having a steep rise, by inserting a capacitor between a base of an NPN transistor (TR) and ground.
CONSTITUTION: A capacitor C0 is inserted between the base of an NPN TRQ2 and ground in a PNPN switch circuit consisting of a PNP TRQ1, a Zener diode D1, the NPN TRQ2 and an NPN Darlington TRQ3. Thus, a transient current flowing to a resistor R2 is reduced through capacitance division to prevent the NPN TRQ2 from turning on. In applying a capacitor to the collector of the NPN TRQ2, the PNPN switch circuit has excellent noise resistance against noise with steep rise. The capacitor can easily be realized by a BC diode.
Inventors:
SATOU HIROAKI
Application Number:
JP18809881A
Publication Date:
May 30, 1983
Filing Date:
November 24, 1981
Export Citation:
Assignee:
NIPPON ELECTRIC CO
International Classes:
H02M1/08; H03K17/16; H03K17/615; H03K17/73; H03K17/732; (IPC1-7): H03K17/16; H03K17/72
Domestic Patent References:
| JPS5521542A | 1980-02-15 |
Attorney, Agent or Firm:
Uchihara Shin