Bias current supply techniques
AssigneeAnalog Devices Global Unlimited Company
InventorsChristopher Peter Hurrell, Derek J. Hummerston
Life of this patent
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Abstract
Techniques for supplying a bias current to a load are provided. In certain examples, a circuit can include a level-shift capacitance, a current source, and a load configured to receive a bias current in a first state of the circuit. The current source and the level-shift capacitance can be coupled in series between the load and a supply voltage in the first state. In some examples, during a second state of the circuit, the level-shift capacitance can receive charge, and can be isolated from one of the load or the current source.
Claims20
A circuit comprising:
- a transistor load;
- and
- a supply circuit configured to receive a supply voltage and to supply an operating current to the transistor load during a first state of the circuit and to charge a level-shift capacitor during a second state of the circuit, the supply circuit comprising:
- the level-shift capacitor;
- and
- a current source;
- wherein the level-shift capacitor is coupled in series with the current source to supply the operating current to the transistor load during the first state;
- and
- wherein the level-shift capacitor is isolated from the current source during the second state.
A method of providing a bias current to a load, the method comprising:
- isolating a level-shift capacitor of a supply circuit from a current source of the supply circuit during a first state of the supply circuit;
- charging the level-shift capacitor during the first state of the supply circuit;
- coupling the level shift capacitor and a current source together in series to provide a series-connect level-shift capacitor and current source;
- and
- coupling the series-connected level-shift capacitor and current source to a bias input of the load to supply the bias current to the load during a second state of the supply circuit.
A circuit comprising:
- a load configured to receive a bias current in a first state of the circuit;
- a level-shift capacitance;
- and
- a current source;
- wherein the current source and the capacitance are coupled in series between the load and a supply voltage in the first state;
- wherein the capacitance is configured to receive charge during a second state of the circuit;
- and
- wherein the capacitor is isolated from the current source during the second state.
Dependencies are inferred from the claim text.