CIRCUITS AND METHODS TO USE ENERGY HARVESTED FROM TRANSIENT ON-CHIP DATA
Circuits and methods that use harvested electrostatic energy from transient: on-chip data are described in the Application. In one aspect, a method inverter circuit use harvested electrostatic charge held at any electric potential higher than the common ground reference potential of CMOS circuits in a chip, to partially drive a 0→1 logic transition at the output of the inverter at lower energy drain from the on-chip power grid than a conventional CMOS inverter with similar performance, slew rates at inverter input and output and with similar output driving transistor geometries.
1 . (canceled)
2 . An apparatus, comprising:
a power supply voltage terminal configured to provide a power supply voltage;
an input terminal;
an output terminal;
a shared capacitor terminal operatively coupled to the output terminal; and
a circuit switch associated with a delay, the circuit switch configured to, responsive to a high-to-low logic transition at the input terminal, sequentially ( 1 ) electrically couple then decouple the shared capacitor terminal and the output terminal via a first pulse and (2) electrically couple then decouple the shared capacitor terminal and the output terminal via a second pulse, the second pulse beginning after the first pulse begins and after the delay, the second pulse partially overlapping the first pulse.
3 . The apparatus of claim 2 , further comprising:
a NOR gate including a first input, a second input, and an output, the first input of the NOR gate being the input terminal and the second input of the NOR gate connected to the output terminal.
4 . The apparatus of claim 2 , further comprising:
a NOR gate including a first input, a second input, and an output, the first input of the NOR gate being the input terminal and the second input of the NOR gate connected to the output terminal; and
a first NFET including a gate terminal, a source terminal, and a drain terminal, the gate terminal of the first NFET connected to the input terminal, the source terminal of the first NFET connected to reference ground, the drain terminal of the first NFET connected to the output terminal.
5 . The apparatus of claim 2 , further comprising:
a NOR gate including a first input, a second input, and an output, the first input of the NOR gate being the input terminal and the second input of the NOR gate connected to the output terminal;
a first NFET including a gate terminal, a source terminal, and a drain terminal, the gate terminal of the first NFET connected to the input terminal, the source terminal of the first NFET connected to reference ground, the drain terminal of the first NFET connected to the output terminal; and
a second NFET including a gate terminal, a source terminal, and a drain terminal, the gate terminal of the second NFET connected to the output of the NOR gate, the source terminal of the second NFET connected to the output terminal, the drain terminal of the second NFET connected to the shared capacitor terminal.
6 . The apparatus of claim 2 , wherein
a NOR gate including a first input, a second input, and an output, the first input of the NOR gate being the input terminal and the second input of the NOR gate connected to the output terminal;
a first NFET including a gate terminal, a source terminal, and a drain terminal, the gate terminal of the first NFET connected to the input terminal, the source terminal of the first NFET connected to reference ground, the drain terminal of the first NFET connected to the output terminal;
a second NFET including a gate terminal, a source, a terminal, and a drain terminal, the gate terminal of the second NFET connected to the output of the NOR gate, the source terminal of the second NFET connected to the output terminal, the drain terminal of the second NFET connected to the shared capacitor terminal; and
following the high-to-low logic transition at the input terminal, a leading edge of an active-high pulse at the output of the NOR gate activates the second NFET during operation such that harvested charge on the shared capacitor terminal charges the output terminal raising a voltage at the output terminal above the reference ground.
7 . The apparatus of claim 2 , further comprising:
a NOR gate including a first input, a second input, and an output, the first input of the NOR gate being the input terminal and the second input of the NOR gate connected to the output terminal;
a first NFET including a gate terminal, a source terminal, and a drain terminal, the gate terminal of the first NFET connected to the input terminal, the source terminal of the first NFET connected to reference ground, the drain terminal of the first NFET connected to the output terminal;
a second NFET including a gate terminal, a source, a terminal, and a drain terminal, the gate terminal of the second NFET connected to the output of the NOR gate, the source terminal of the second NFET connected to the output terminal, the drain terminal of the second NFET connected to the shared capacitor terminal;
following the high-to-low logic transition at the input terminal, a leading edge of an active-high pulse at the output of the NOR gate activates the second NFET during operation such that harvested charge on at the shared capacitor terminal discharges the output terminal raising a voltage at the output terminal above the reference ground; and
a PFET including a gate terminal, a source terminal, and a drain terminal, the source terminal of the PFET being connected to the power supply voltage terminal and the drain terminal of the PFET being connected to the output terminal.
8 . The apparatus of claim 2 , further comprising:
a NOR gate including a first input, a second input, and an output, the first input of the NOR gate being the input terminal and the second input of the NOR gate connected to the output terminal;
a first NFET including a gate terminal, a source terminal, and a drain terminal, the gate terminal of the first NFET connected to the input terminal, the source terminal of the first NFET connected to reference ground, the drain terminal of the first NFET connected to the output terminal;
a second NFET including a gate terminal, a source, a terminal, and a drain terminal, the gate terminal of the second NFET connected to the output of the NOR gate, the source terminal of the second NFET connected to the output terminal, the drain terminal of the second NFET connected to the shared capacitor terminal;
following the high-to-low logic transition at the input terminal, a leading edge of an active-high pulse at the output of the NOR gate activates the second NFET during operation such that harvested charge on the shared capacitor terminal discharges the output terminal raising a voltage at the output terminal above the reference ground;
a PFET including a gate terminal, a source terminal, and a drain terminal, the source terminal of the PFET being connected to the power supply voltage terminal and the drain terminal of the PFET being connected to the output terminal; and
an inverter, an input of the inverter connected to the output of the NOR gate, an output of the inverter connected to the gate terminal of the PFET.
9 . The apparatus of claim 8 , wherein an active high pulse at the input of the inverter during operation causes the PFET to activate for a duration equal to a pulse duration of the active high pulse.
10 . The apparatus of claim 8 , wherein a propagation delay of the inverter during operation is substantially similar to a time for the output terminal to be charged from the reference ground to a voltage comparable to a voltage at the shared capacitor terminal.
11 . The apparatus of claim 8 , wherein, during operation, a pulse width of an active high pulse at the output of the NOR gate is comparable to a sum of a propagation delay of the inverter and a time for the PFET to charge the output terminal to a logic threshold voltage of the NOR gate.
12 . The apparatus of claim 11 , wherein, during operation:
the high-to-low logic transition at the input terminal causes the active high pulse at the output of the NOR gate,
the active high pulse at the output of the NOR gate causes the second NFET to be activated, and
the active high pulse at the output of the NOR gate, delayed by the inverter, causes the PFET to be activated
13 . The apparatus of claim 2 , further comprising:
a PFET including a gate terminal, a source terminal, and a drain terminal, the gate terminal of the PFET connected to the input terminal, the source terminal of the PFET connected to the power supply voltage terminal, and the drain terminal connected to the output terminal.
14 . An apparatus, comprising:
a power supply voltage terminal configured to provide a power supply voltage;
a reference ground voltage terminal;
a node ( 1 ) operatively coupled to an output terminal and (2) configured to provide a node voltage;
an input terminal; and
the output terminal.
15 . The apparatus of claim 14 , further comprising:
a NOR gate including a first input, a second input, and an output, the first input of the NOR gate being the input terminal and the second input of the NOR gate connected to the output terminal;
a first NFET including a gate terminal, a source terminal, and a drain terminal, the gate terminal of the first NFET connected to the input terminal, the source terminal of the first NFET connected to the reference ground voltage terminal, the drain terminal of the first NFET connected to the output terminal;
a second NFET including a gate terminal, a source, terminal, and a drain terminal, the gate terminal of the second NFET connected to the output of the NOR gate, the source terminal of the second NFET connected to the output terminal, the drain terminal of the second NFET connected to the node;
a first PFET including a gate terminal, a source terminal, and a drain terminal, the source terminal of the first PFET being connected to the power supply voltage terminal and the drain terminal of the first PFET being connected to the output terminal;
an inverter, an input of the inverter connected to the output of the NOR gate, an output of the inverter connected to the gate terminal of the first PFET; and
a second PFET including a gate terminal, a source terminal, and a drain terminal, the gate terminal of the second PFET connected to the input terminal, the source terminal of the second PFET connected to the power supply voltage terminal, and the drain terminal of the second PFET connected to the output terminal.
16 . The apparatus of claim 15 , wherein, during operation, following a high-to-low logic transition at the input terminal, a leading edge of an active-high pulse at the output of the NOR gate activates the second NFET such that harvested charge at the node is discharged to the output terminal.
17 . The apparatus of claim 15 , wherein an active high pulse at the input of the inverter during operation causes the first PFET to activate for a duration equal to a pulse duration of the active high pulse.
18 . The apparatus of claim 15 , wherein a propagation delay of the inverter during operation is substantially comparable to a time for the output terminal to be charged from the reference ground voltage terminal to the node voltage.
19 . The apparatus of claim 15 , wherein, during operation:
a high-to-low logic transition at the input terminal causes an active high pulse at the output of the NOR gate,
the active high pulse at the output of the NOR gate causes the second NFET to be activated, and
the active high pulse at the output of the NOR gate causes the inverter to activate the first PFET.
20 . A method, comprising:
providing a power supply voltage at a power supply voltage terminal;
providing a node voltage at a node operatively coupled to an output terminal; and
receiving, at the output terminal, a low-to-high logic transition driven by the node voltage then the power supply voltage following a high-to-low logic transition at an input terminal.
21 . The method of claim 20 , wherein an energy consumed to drive a low-to-high logic transition at the output terminal is partially provided by the power supply voltage terminal and partially provided by the node.