High frequency charge pump/integrator circuit
AssigneeTexas Instruments Incorporated
InventorsJohn D. Morgan, William H. Giolma, Richard Boucher
Life of this patent
Estimating the term…
Abstract
A dropping resistor and a pair of differential current steering pairs coupled to the resistor with each operable to draw and cease drawing current through the resistor in response to associated corresponding input signals. An integrator is coupled through an emitter follower to one end of the resistor for integrating the current due to the difference in voltage from that voltage established when only one of the pair draws current through the resistor. Preferably the resistor is integrated on a semiconductor chip together with the remainder of the charge pump and integrator circuitry.
Claims12
A charge pump circuit, comprising
- a dropping resistor;
- a current steering circuit having an output coupled to said dropping resistor and having a pair of inputs for receiving respective input signals, said current steering circuit being responsive to a first condition of said input signals for drawing no current through said dropping resistor, being responsive to a second condition of said input signals for drawing a first level of current through said dropping resistor, and being responsive to a third condition of said input signals for drawing a second level of current through said dropping resistor, wherein said second level of current is greater than said first level of current;
- and
- an integrator circuit having an input coupled to said dropping resistor for integrating a current caused by the voltage change across said dropping resistor, said voltage change being with respect to a voltage established by said first level of current flowing through said dropping resistor.
A charge pump circuit, comprising:
- a dropping resistor;
- a pair of differential current steering circuits, each circuit having an output coupled to a first end of said dropping resistor, each current steering circuit being responsive to a respective input signal to draw and cease drawing current through the dropping resistor;
- and
- a pump resistor coupled to said first end of said dropping resistor for providing an output current of a given sense when both said current steering circuits draw current through said dropping resistor, for providing an output current of an opposite sense when neither of said current steering circuits draws current through said dropping resistor and for providing substantially no output current when one of said current steering circuits draws current through said dropping resistor and the other does not.
A charge pump circuit, comprising:
- a dropping resistor connected between a source of supply voltage and a circuit node;
- a switched current source having a first operating mode for supplying a given current in a given sense to said node, having a second operating mode for supplying twice said given current in said given sense to said node and having a third operating mode for supplying substantially no current to said node;
- an amplifier having an input coupled via a pump resistor to said node;
- a reference voltage source connected to a reference input of said amplifier providing a voltage selected for causing said pump resistor to supply substantially no current to said amplifier during said first operating mode of said switched current source;
- and wherein
- said dropping resistor, said pump resistor, said switched current source, said reference voltage source and said amplifier each being formed in an integrated circuit.
Dependencies are inferred from the claim text.