Patent ID: 7116594

Claim:
A sense amplifier circuit comprising: an isolation device comprising a control terminal and first and second terminals, the first terminal of the isolation device coupled to a signal line; a gated diode comprising first and second terminals, the first terminal of the gated diode coupled to the second terminal of the isolation device, and the second terminal of the gated diode coupled to a set line; and control circuitry coupled to the control terminal of the isolation device and adapted to control voltage on the control terminal of the isolation device in order to enable and disable the isolation device, the control circuitry additionally coupled to the set line and adapted to control a voltage on the set line; wherein the signal line is adapted to be coupled to an input signal, and wherein the second terminal of the isolation device is adapted to be used to derive an output for the sense amplifier circuit; wherein said gated diode has a substantially large equivalent capacitance when a threshold voltage of said gated diode is a positive voltage and when a voltage on said first terminal relative to said second terminal is greater than said threshold voltage; wherein said gated diode has a substantially small equivalent capacitance when said threshold voltage of said gated diode is a positive voltage and when said voltage on said first terminal relative to said second terminal is not greater than said threshold voltage; wherein said gated diode has a substantially large equivalent capacitance when said threshold voltage of said gated diode is a negative voltage and when a voltage on said first terminal relative to said second terminal is not greater than said threshold voltage; and wherein said gated diode has a substantially small equivalent capacitance when said threshold voltage of said gated diode is a negative voltage and when said voltage on said first terminal relative to said second terminal is greater than said threshold voltage.