Bidirectional charge pump generating either a positive or negative voltage

A charge pump for coupling to first and second terminals of a voltage supply to receive a supply voltage having a magnitude and a polarity with respect to a reference voltage and for generating a boosted voltage having a magnitude and a polarity, the charge pump comprising:

• a first input to couple to the first terminal of the voltage supply to receive the supply voltage;
• a second input to couple to the second terminal of the voltage supply to receive the reference voltage;
• a charge pump circuit having a first voltage node and a second voltage node, the charge pump circuit being configured to transfer electrical charge from the first node to the second node;
• a first switch that selectively couples the first node of the charge pump circuit to the first input;
• and
• a second switch that selectively couples the second node of the charge pump circuit to the second input;
• wherein in a first operating condition, the first switch couples the first node to the first input and the second switch substantially isolates the second node from the second input, and in a second operating condition, the second switch couples the second input to the second node and the first switch substantially isolates the first node from the first input;
• and
• wherein in the first operating mode, the second node of the charge pump circuit acquires a voltage having a polarity equal to the polarity of the supply voltage and having a magnitude greater than the magnitude of the supply voltage, and in the second operating mode, the first node of the charge pump circuit acquires a voltage having a polarity opposite the polarity of the supply voltage and a magnitude greater than the magnitude of the supply voltage.

A charge pump for coupling to first and second terminals of a voltage supply to receive a supply voltage having a magnitude and a polarity with respect to a reference voltage and for generating a boosted voltage having a magnitude and a polarity, the charge pump comprising:

• a first input to couple to the first terminal of the voltage supply to receive the supply voltage;
• a second input to couple to the second terminal of the voltage supply to receive the reference voltage;
• a charge pump circuit having a first voltage node and a second voltage node, the charge pump circuit being configured to transfer electrical charge from the first node to the second node;
• a first switch that selectively couples the first node of the charge pump circuit to the first input;
• a second switch that selectively couples the second node of the charge pump circuit to the second input;
• at least one charge pump stage having a first input coupled to the first node, a second input, an output, a first diode coupled between the first input and the output of the charge pump stage, and a capacitor coupled between the output and the second input;
• and
• a second diode coupled between the output of the at least one charge pump stage and the second node of the charge pump circuit.

A charge pump for coupling to a voltage supply to receive a supply voltage having a magnitude and a polarity with respect to a reference voltage and for generating a boosted voltage having a magnitude and a polarity, the charge pump comprising:

• a charge pump circuit having a first voltage node and a second voltage node, the charge pump circuit being configured to transfer electrical charge from the first node to the second node;
• means for coupling the charge pump circuit to the reference voltage for a first mode of operation of the charge pump for producing a voltage at the first node having a polarity opposite the polarity of the supply voltage and having a magnitude greater than the magnitude of the supply voltage;
• and
• means for coupling the charge pump circuit to the voltage supply for a second mode of operation of the charge pump circuit for producing a voltage at the second node having a polarity equal to the polarity of the supply voltage and having a magnitude greater than the magnitude of the supply voltage.

A method of generating a boosted voltage having a magnitude and a polarity with respect to a reference voltage using a supply voltage having a magnitude and a polarity with respect to the reference voltage, the method comprising steps of:

• providing a charge pump circuit having a first voltage node and a second voltage node, the charge pump circuit being configured to transfer electrical charge from the first node to the second node;
• applying the supply voltage to the first node of the charge pump circuit to produce a boosted voltage at the second node, the boosted voltage having a polarity equal to the polarity of the supply voltage and having a magnitude greater than the magnitude of the supply voltage;
• and
• applying the reference voltage to the second node of the charge pump circuit to produce a boosted voltage at the first node, the boosted voltage having a polarity opposite the polarity of the supply voltage and having a magnitude greater than the magnitude of the supply voltage.

A memory device comprising:

• a first input to receive a supply voltage having a magnitude and a polarity with respect to a reference voltage;
• a second input to receive the reference voltage;
• a charge pump coupled to the first and second inputs to respectively receive the supply voltage and the reference voltage, the charge pump including:
• a charge pump circuit having a first voltage node and a second voltage node, the charge pump circuit being configured to transfer electrical charge from the first node to the second node;
• a first switch that selectively couples the first node of the charge pump circuit to the first input of the memory device;
• and
• a second switch that selectively couples the second node of the charge pump circuit to the second input of the memory device;
• and
• a first clock input to receive a first clock signal;
• and
• a clock generator coupled to the first clock input of the charge pump circuit to provide the first clock signal;
• wherein in a first operational mode of the memory device, the first switch couples the first node to the first input and the second switch substantially isolates the second node from the second input, and in a second operational mode of the memory device, the second switch couples the second input to the second node and the first switch substantially isolates the first node from the first input;
• and
• wherein in the first operational mode, the second node of the charge pump circuit acquires a voltage having a polarity equal to the polarity of the supply voltage and having a magnitude greater than the magnitude of the supply voltage, and in the second operational mode, the first node of the charge pump circuit acquires a voltage having a polarity opposite the polarity of the supply voltage and a magnitude greater than the magnitude of the supply voltage.

A memory device comprising:

• a first input to receive a supply voltage having a magnitude and a polarity with respect to a reference voltage;
• a second input to receive the reference voltage;
• a charge pump coupled to the first and second inputs to respectively receive the supply voltage and the reference voltage, the charge pump including:
• a charge pump circuit having a first voltage node and a second voltage node, the charge pump circuit being configured to transfer electrical charge from the first node to the second node;
• a first switch that selectively couples the first node of the charge pump circuit to the first input of the memory device;
• a second switch that selectively couples the second node of the charge pump circuit to the second input of the memory device;
• a first clock input to receive a first clock signal;
• a clock generator coupled to the first clock input of the charge pump circuit to provide the first clock signal;
• at least one charge pump stage having a first input coupled to the first node, a second input, an output, a first diode coupled between the first input of the charge pump stage and the output, and a capacitor coupled between the output and the second input of the charge pump stage;
• and
• a second diode coupled between the output of the at least one charge pump stage and the second node of the charge pump circuit.