| 摘要 |
PURPOSE:To discriminate easily and surely a failed part after the package assembling of a memory provided with a redundancy circuit by connecting a fuse of a programmable element and a transistor (TR) of diode operation and impressing a reverse potential to the connection. CONSTITUTION:No current is conducted to the FETQ3, Q4 of diode connection connected to the fuse 4 of a discriminating circuit 3 at the normal operation when voltages at terminals VCC, VSS are at power supply voltage and ground voltage respectively, and no effect on an output buffer circuit is given because of the connection of the circuit 3. In impressing the reverse potential to the terminals VCC and VSS, when the fuse 4 is not blown, a node N1' reaches a prescribed voltage dividing potential by the FETQ3, Q4, and when the fuse is blown, the potential reaches a high potential depending on the FETQ4. When the potential depending on the discrimination of the presence of a failure via the bonding and section 2 is observed, the discrimination of a failed part is attained easily and surely even after the package assembling. |
