Sensing module, memory device, and sensing method applied to identify un-programmed/programmed state of non-volatile memory cell

A memory device, comprising:

• a memory circuit, comprising:
• M bit lines, arranged in parallel with a first direction;
• N word lines, arranged in parallel with a second direction;
• and
• M*N memory units, wherein a selected memory unit among the M*N memory units is electrically connected to an m-th bit line among the M bit lines and an n-th word line among the N word lines;
• and
• a sensing module, electrically connected to the M bit lines, configured to perform a read operation to the selected memory unit, comprising:
• a sensing amplifier, electrically connected to the selected memory unit at a clamp terminal, configured to generate a sensing current and identify a state of the memory cell based on the sensing current, wherein the clamp terminal is clamped at a low read voltage during the read operation;
• and
• a current sink, electrically connected to the clamp terminal, configured to receive a reference current being equivalent to a summation of the sensing current and a cell current flowing through a memory cell in the selected memory unit, wherein both the sensing current and the cell current flow to the current sink via the clamp terminal, the reference current is constant, and the sensing current is changed with the cell current,
• wherein the cell current is generated based on a high read voltage and the low read voltage being applied to the memory cell, wherein
• the sensing current is higher if the memory cell is un-programmed, and
• the sensing current is lower if the memory cell is programmed.

A sensing method applied to a sensing module being configured to read a state of a memory cell, wherein the sensing method comprises steps of:

• applying a high read voltage and a low read voltage to the memory cell so that a cell current flowing through the memory cell and a clamp terminal is generated, wherein the clamp terminal is clamped at the low read voltage when a state of the memory cell is being read;
• generating a sensing current, wherein the sensing current is higher if the memory cell is un-programmed, and the sensing current is lower if the memory cell is programmed;
• a current sink receiving a reference current being equivalent to a summation of the sensing current and the cell current, wherein both the sensing current and the cell current flow to the current sink via the clamp terminal, the reference current is constant, and the sensing current is changed with the cell current;
• and
• identifying the state of the memory cell based on the sensing current.