Antifuse circuit being programmable by using no connection pin

摘要

An antifuse circuit provides a stabilized high voltage to an antifuse programming circuit through the use of an NC pin which is not used in the chip operation. For the purpose, the antifuse circuit includes a power-up detecting circuit for generating a power stabilization signal by detecting a supply voltage; a power-up pulse circuit for generating a first and a second control signal in response to the power stabilization signal; an antifuse programming circuit for, under the control of the first and the second control signals, detecting whether an antifuse element is programmed or not, latching the result of the detection and programming the antifuse element in response to an external high voltage and a precharge signal; a pin for receiving the external high voltage so as to program the antifuse element; a pad for providing the external high voltage to the inside of the chip; and a diode for supplying the external high voltage to the antifuse programming circuit and preventing a voltage of the antifuse programming circuit from being provided to the pin.