Systems and methods for minimizing static leakage of an integrated circuit
View Patent ↗To minimize static leakage of an integrated circuit, a charge pump generates a negative voltage to be applied to a “sleep” transistor cascaded to a logic gate of the integrated circuit. An adaptive leakage controller determines continuously or periodically whether to adjust the negative voltage to minimize the static leakage. A negative voltage regulator adjusts the negative voltage depending on the determination. Some embodiments determine whether to adjust the negative voltage by monitoring one or more parameters of the sleep transistor. Some embodiments determine whether to adjust the negative voltage by monitoring one or more parameters of an emulated sleep transistor.
1. A charge pump circuit for minimizing static leakage of a logic gate, comprising:
two capacitances, each having first and second terminals, the first terminal of one of the capacitances at a first circuit input for receiving an alternating signal, the first terminal of the other of the capacitances at a second circuit input for receiving a complement of the alternating signal;
first and second PMOS switches, a gate of each said switches electrically connected to a different one of the second terminals of said two capacitances;
a pump capacitor having first and second terminals, the first terminal electrically connected to both sources of the switches;
an inverter having an input and an output, said output of the inverter electrically connected to said second terminal of the pump capacitor, said input of the inverter receiving said alternating signal;
a negative pass gate having at least two terminals, a first terminal of said negative pass gate electrically connected to the second terminal of the other of the capacitances, and a second terminal of said negative pass gate electrically connected to virtual ground; and
a positive pass gate having at least two terminals, a first terminal of said positive pass gate electrically connected to the second terminal of the one of the capacitances, and a second terminal of said positive pass gate electrically connected to said virtual ground,
the drain of the second switch at a negative output, the negative output configured to supply a negative voltage to a sleep transistor to control static leakage of the logic gate.
2. The charge pump as claimed in claim 1 , wherein the pass gates comprise PMOS transistors.
3. The charge pump as claimed in claim 1 , wherein the pass gates are cross-coupled pass gates.
4. The charge pump as claimed in claim 1 , wherein the drain of the first switch is electrically connected to ground.
5. The charge pump as claimed in claim 1 , further comprising an inverter coupled to said virtual ground, said inverter being configured to apply a positive voltage to said virtual ground to inhibit the charge pump.
6. The charge pump as claimed in claim 1 , wherein said virtual ground comprises a substrate of an integrated circuit.