Method for characterizing an active track and latch sense-amp (comparator) in a one time programmable (OTP) salicided poly fuse array
AssigneeKoninklijke Philips Electronics N.V.
InventorElie Georges Khoury
Life of this patent
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Abstract
A non intrusive isolation testing method for each of the positive and negative input (in+ & in−) to each comparator in the array is provided. Isolation does not affect the read capability of the comparator and therefore characterization of the comparator is accomplished by using the normal read circuits of the one time programmable (OTP) array. The isolation method relies on gating the control signals by using test signals; as a result inputs to a comparator are not affected electrically. Each input has four possible control signals and therefore needs four gating test signal drivers and so a total of 16 input combinations are available to each comparator.
Claims22
An integrated circuit comprising:
- a comparator including:
- a comparison circuit, a first input port, a second input port, and an output port;
- a first external port for use in characterizing of the comparator;
- and,
- a first switch integral to the integrated circuit and in electrical communication with the first input port for switchably selecting between a first plurality of input signals wherein at least one input signal from the first plurality of input signals is in accordance with the circuit operation requirements and another input signal from the first plurality of input signals switchably selected using the first external port is solely for use in characterizing of the comparator.
A non-intrusive method of characterizing a comparator circuit having a first input port and a second input port and an output port within an integrated circuit memory comprising the steps of:
- providing power to the comparator circuit;
- providing at least an external port;
- providing a plurality of switches within the integrated circuit in electrical communication with the input ports of the comparator circuit for switchably selecting between at least one of a plurality of input signals to the comparator and the at least an external port;
- switching at least a first input signal to the first input port of the comparator;
- switching at least a second input signal to the second input port of the comparator;
- verifying at least one of the at least a first input signal and the at least a second input signal;
- and,
- monitoring at least one of an output signal provided at the output port in response to at least one of the at least a first signal and the at least a second signal and the at least one of the at least a first signal and the at least a second signal using the at least an external port.
Dependencies are inferred from the claim text.