Patent ID: 6856564

Claim:
A sensing circuit having a sensing node electrically coupled to a memory cell and reference node electrically coupled to a reference level, the sensing circuit comprising: a differential amplifier having first and second differential input nodes and first and second differential output nodes; a switching circuit having first and second switching input terminals and first and second switching output terminals, and a clock node at which a first clock signal is applied, the switching circuit electrically coupled to the first and second differential input nodes and the first and second differential output nodes and, in accordance with the first clock signal, switching the coupling of the first and second switching input nodes to a respective one of the first and second differential input nodes and switching the coupling of the first and second switching output nodes of a respective one of the first and second differential output nodes; first and second capacitors electrically coupled to a respective switching output node; a clocked comparator having an output node, a clock node at which a second clock signal is applied, and first and second input nodes electrically coupled to the first and second capacitors, respectively, in response to the second clock signal, the clocked comparator generating an output signal having a logic state based on the relative voltage levels of the first and second capacitors; and a current source having first and second current output nodes electrically coupled to a respective one of the capacitors, the current source switching the coupling of each current output node to a respective one of the capacitors based on the logic state of the output signal of the clocked comparator.