Dual differential trans-impedance sense amplifier and method

A sense amplifier circuit connected to a semiconductor memory, comprising:

• (a) current inverting means for receiving a reference current from a reference column in said semiconductor memory, said current inverting means producing a first and second inverted electric current both precisely half but opposite in flow direction versus the reference current;
• (b) first trans-impedance means for receiving a difference of a first cell electric current from a first selected core memory cell indicative of its memory state, and said first inverted electric current from said current inverting means;
• (c) second trans-impedance means for receiving a difference of a second cell electric current from a second selected core memory cell indicative of its memory state, and said second inverted electric current from said current inverting means, each of said current inverting means, first and second trans-impedance means being effective for both pushing and pulling currents into and out of themselves;
• and
• (d) bias means for biasing said current inverting means and the first and second trans-impedance means, wherein said bias means is effective for providing a temperature compensated bias voltage to each of said current inverting and first and second trans-impedance means.

A method of memory cell sense determination by combining sense and reference currents received respectively from a core memory cell in a semiconductor memory and from a reference cell in said semiconductor memory, comprising the steps of:

• (a) receiving said reference current from said reference cell in said semiconductor memory;
• (b) differencing a selected portion of said reference current with said sense current from the core memory cell in said semiconductor memory into a low impedance summation node to produce a differential current indicative of the state of said core memory cell;
• and
• (c) receiving said differential current with a trans-impedance circuit effective for producing an output signal responsive to said differential current and effective for sourcing and sinking said differential current depending on its direction of flow.