Current sensing circuit using proportional current mirrors

A current sensing circuit, comprising:

• a differential sensing amplifier, comprises a first input end, a second input end and an output end, wherein the first input end is coupled to a selected cell via a first data line, the second input end is coupled to a reference cell via a second data line, and the output end outputs a sensing data of the selected cell;
• and
• a pre-charging circuit, coupled to the differential sensing amplifier, and the pre-charging circuit is configured to provide a pre-charging current and perform a pre-charging operation on the first data line,
• wherein the first data line has a cell current and the pre-charging current, the second data line has a reference current, and the pre-charging current is determined according to the reference current, wherein the pre-charging current is greater than the reference current, and the pre-charging current is proportional to the reference current.