Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
PROGRAM CIRCUIT
Document Type and Number:
Japanese Patent JPH05242691
Kind Code:
A
Abstract:

PURPOSE: To prevent a malfunction of a program circuit when a fuse circuit supposed to be cut is connected with a high resistance and a power supply voltage VCC is slowly rising.

CONSTITUTION: A circuit 1 is a delay circuit with a VCC power supply as an input and a contact point D is once charged up to a high level by a P channel MOS transistor 4 when a power supply is turned on. After the elapse of the delaying time of the circuit 1, the transistor 4 is turned off and an inverter circuit 2 outputs a low level. When a fuse is not cut, the contact point D becomes a low level by the circuit 2. When the fuse is cut, the high level is held. When the fuse is connected with a high resistance, the circuit 2 does not make the potential of the contact point D to a low level because of the high resistance fuse regardless of the rising VCC power supply and a malfunction of the program circuit is prevented.


Inventors:
SERIZAWA KENICHI
Application Number:
JP3999092A
Publication Date:
September 21, 1993
Filing Date:
February 27, 1992
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
NIPPON ELECTRIC IC MICROCOMPUT
International Classes:
G11C17/14; (IPC1-7): G11C17/14
Attorney, Agent or Firm:
Naoki Kyomoto (2 outside)



 
Previous Patent: JPS5242690

Next Patent: JPS5242692