1. A method comprising: an electronic device generating a pre-synaptic pulse that starts at a baseline value and reaches a first voltage value a first period of time after receiving a pre-synaptic spike at a first input, followed by a second voltage value a second period of time after said pre-synaptic spike, followed by a return to said baseline voltage a third period of time after said pre-synaptic spike; the electronic device generating a post-synaptic pulse that occurs a predetermined period of time after receiving a post-synaptic spike at a second input; applying said generated pre-synaptic pulse to a pre-synaptic node of a synaptic device in series with a rectifying element comprising a turn-on voltage based on a threshold; and applying said generated post-synaptic pulse to a post-synaptic node of said synaptic device; wherein said synaptic device comprises a phase change memory (PCM) that has a set voltage, a reset voltage and a threshold voltage; and wherein said pre-synaptic pulse has a magnitude greater than said turn-on voltage but less than the sum of said turn-on voltage and said threshold voltage.