Patent ID: 7304527

Claim:
A fuse sensing circuit comprising: a first amplifier circuit having first and second inputs and first and second outputs; a fuse connected between a first node and the first input of the first amplifier circuit; a reference resistor connected between the first node and the second input of the first amplifier circuit; a second amplifier circuit, which is a differential amplifier, having first and second inputs, the first and second outputs of the first amplifier circuit being connected to the first and second inputs of the second amplifier circuit, the second amplifier circuit comprising first and second PMOS transistors and first and second NMOS transistors, each transistor having a source, a drain and a gate, the first PMOS transistor and first NMOS transistor being connected in series between a second node and ground and the second PMOS transistor and the second NMOS transistor being connected in series between the second node and ground; a switch for connecting the second node to a power supply; whereby the first amplifier circuit generates an output signal on its first and second outputs indicative of whether the fuse is programmed or not and the second amplifier circuit generates an output signal on a first output indicative of whether the fuse is programmed or not.