Sensing circuit and method

A circuit (28) and method of sensing data stored in a memory circuit provide a reference current (IREF) that tracks memory cell current (IBIT) over a range of temperatures and power supply voltages. A comparator circuit (66) senses the memory cell current with respect to the reference current to produce the stored data (VDATA) By sensing current rather than voltage, the voltage swing on a high capacitance bitline (39) can be reduced to improve speed. The reference current is set during testing of the circuit by applying programming voltages (VWELL, VCG, VBL) to a reference device (52) that matches a storage device (36) in the memory cell (30).