A passive element memory device is provided that includes memory cells
comprised of a state change element in series with a steering element.
Controlled pulse operations are used to perform resistance changes
associated with set and reset operations in an array of memory cells.
Selected memory cells in an array are switched to a target resistance
state in one embodiment by applying a positive voltage pulse to selected
first array lines while applying a negative voltage pulse to selected
second array lines. An amplitude of voltage pulses can be increased while
being applied to efficiently and safely switch the resistance of cells
having different operating characteristics. The cells are subjected to
reverse biases in embodiments to lower leakage currents and increase
bandwidth. The amplitude and duration of voltage pulses are controlled,
along with the current applied to selected memory cells in some
embodiments. These controlled pulse-based operations can be used to set
memory cells to a lower resistance state or reset memory cells to a
higher resistance state in various embodiments.