A memory device comprises a memory block, a power gating transistor, and control circuitry. The memory block includes at least one memory cell comprising a storage element electrically connected to a source potential line, a drive strength of the storage element being a function of a voltage level on the source potential line. The power gating transistor, in turn, is connected between the source potential line and a voltage source. The control circuitry is operative to configure the power gating transistor to electrically connect the source potential line to the voltage source while the memory block is in a first mode, and to clamp the source potential line at a voltage different from that of the voltage source when the memory block is in a second mode.