Abstract: A sensing circuit for a non-volatile memory operating from a supply voltage and comprising non-volatile memory cells and a non-volatile reference cell maintained in an un-programmed condition, the sensing circuit comprising means for determining the sensed current of a memory cell when accessed and comparing it with the reference current to determine whether the accessed memory cell is programmed or un-programmed. To allow opertion over a wide range of supply voltages, the sensing circuit comprises a scalable current mirror circuit connected to the reference and memory cells and providing a ratio, M, of reference current to sensed current that, in response to changes in the supply voltage, varies.