A differential PCM memory may include first and second PCM elements, and a sense amplifier circuit configured to sense a difference between first and second sense currents passing through the first and second PCM elements, respectively, during a sense operation. The differential PCM memory may include a first margin current branch coupled in parallel with the first PCM element and configured to selectively add a first margin current to the first sense current, and a second margin current branch coupled in parallel with the second PCM element and configured to selectively add a second margin current to the second sense current.