US 6,184,594 B2 · Multi-stage charge pump having high-voltage pump control feedback and method of operating same

Abstract

A charge pump circuit having a plurality of serially-connected stages. A first stage, which operates in response to a VDD supply voltage and a clock signal, alternately charges and discharges a pair of capacitors to generate a pair of first output voltages, each having a peak voltage which is approximately twice the VDD supply voltage. The first output voltages are provided to a second stage. The second stage alternately charges and discharges a pair of capacitors using the first output voltages, thereby generating a pair of second output voltages that are approximately twice the first output voltage. Each successive charge pump stage uses the output voltages provided by the previous stage to generate output voltages that are approximately twice as large. Some voltage drop is experienced as the output voltages are transmitted from stage to stage through pass transistors. The output voltages provided by various stages can be fed back to control the charging and discharging of the capacitors within the stages. For example, the second output voltages can be fed back to the second stage to control pass transistors that are used to charge capacitors within the second stage.

Claims13

Dependent claims

A charge pump circuit comprising:

a first stage coupled to receive an input signal, wherein the first stage is configured to generate first output signal and a complementary second output signal in response to the input signal, the first and second output signals each varying between a first voltage and a second voltage that is approximately twice the first voltage;
a second stage coupled to receive the first and second output signals from the first stage, wherein the second stage is configured to generate a third output signal and a complementary fourth output signal in response to the first and second output signals, each of the third and fourth output signals varying between the second voltage and a third voltage that is approximately twice the second voltage, the second stage including a first transistor having a drain terminal coupled to receive the first output signal from the first stage, and a second transistor having a drain terminal coupled to receive the second output signal from the first stage;
and
a feedback circuit configured to route the fourth output signal to a gate of the first transistor and configured to route the third output signal to a gate of the second transistor.

1 more element

A method of generating a boosted voltage in response to an input signal, the method comprising the steps of:

generating a first pair of complementary output signals in response to the input signal in a first stage, the first pair of complementary output signals varying between a first voltage and a second voltage that is approximately twice the first voltage;
generating a second pair of complementary output signals in response to the first pair of complementary output signals in a second stage, each of the second pair of complementary output signals varying between the second voltage and a third voltage that is approximately twice the second voltage;
and
providing the second pair of complementary output signals to gates of corresponding transistors which are configured to transmit the first pair of complementary output signals from the first stage to the second stage.

1 more element

A charge pump stage for connection between a previous charge pump stage and a subsequent charge pump stage, the charge pump stage comprising:

a first voltage supply terminal coupled to receive a first supply voltage;
a ground supply terminal coupled to receive a ground supply voltage;
a first capacitor having a first terminal and a second terminal;
a second capacitor having a first terminal and a second terminal;
a switching circuit coupled to the second terminals of the first and second capacitors, wherein during a first half cycle, the switching circuit is configured to couple the second terminal of the first capacitor to the ground supply terminal and the second terminal of the second capacitor to the previous charge pump stage, and wherein during a second half cycle, the switching circuit is configured to couple the second terminal of the first capacitor to the previous charge pump stage and the second terminal of the second capacitor to the ground supply terminal;
a first transistor having a source coupled to the first terminal of the first capacitor, a drain coupled to the previous charge pump stage and a gate coupled to the first terminal of the second capacitor;
and
a second transistor having a source coupled to the first terminal of the second capacitor, a drain coupled to the previous charge pump stage and a gate coupled to the first terminal of the first capacitor.

5 more elements

Dependencies are inferred from the claim text.

Multi-stage charge pump having high-voltage pump control feedback and method of operating same

Life of this patent

Multi-stage charge pump having high-voltage pump control feedback and method of operating same

Life of this patent

Abstract

Claims13