Circuits and methods to harvest energy from transient on-chip data

An apparatus, comprising:

• an inverter having an input terminal and an output terminal;
• a first N-channel field effect transistor (NFET) and a first P channel field effect transistor (PFET) with their drain terminals shorted together at the output terminal of the inverter, a source terminal of the first NFET and a source terminal of the first PFET are connected to a ground and a power supply, respectively;
• a second PFET having a source terminal and a drain terminal configured to couple the output terminal of the inverter to a harvest terminal whose capacitance holds harvested charge at a voltage lower than a voltage of the power supply;
• the input terminal and the output terminal of the inverter, during operation, having electric potentials making full-swing transitions between the voltage of the power supply and a voltage of the ground, the input terminal of the inverter connected directly to a gate input terminal of the first PFET;
• a second NFET having a gate input terminal configured to be driven by the input terminal of the inverter and having a source terminal and a drain terminal connected to the ground and the output terminal of the inverter, respectively;
• and
• a 2-input gate with its inputs configured to be driven by the input terminal and the output terminal of the inverter, the 2-input gate having an output terminal configured to drive a gate input terminal of the second PFET and an input terminal of a delay element having an inverted output configured to drive the first NFET of the inverter.