Current sink system based on sample and hold for source side sensing

A sensing method for a memory cell, the method comprising:

• applying a bias to the memory cell to induce a read current from the memory cell to a data line;
• providing a reference current from a reference current source;
• drawing a sink current from the data line in response to a magnitude of an operating voltage between first and second nodes, including:
• setting the operating voltage between the first and second nodes in response to a magnitude of the reference current during a first time interval using a feedback path;
• and
• holding the operating voltage between the first and second nodes independent of the feedback path during a second time interval following the first time interval;
• and
• determining a data value stored in the memory cell based on a difference in current between the read current and the sink current during the second time interval.

A memory device comprising:

• a memory array arranged to provide a read current from a selected memory cell in the array to a data line;
• a reference current source arranged to provide a reference current;
• current sink circuitry coupled to the data line, the current sink circuitry arranged to draw a sink current from the data line, the current sink circuitry operable to enable a feedback path to establish the sink current during a first time interval, and to disable the feedback path and hold the sink current during a second time interval following the first time interval;
• and
• sense amplifier circuitry coupled to the data line, the sense amplifier circuitry responsive to a difference in current between the read current and the sink current during the second time interval to generate an output signal indicating a data value stored in the selected memory cell.