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US 7,583,148 B2Granted
Transconductance control circuit, method of controlling transconductance, and a power amplifier
AssigneeJennic Limited
InventorKim Ll
Life of this patent
Estimating the term…
Abstract
A transconductance control circuit, comprising: a test transconductance circuit for providing an output current from a reference voltage; apparatus for deriving a bias current for the test transconductance circuit from the output current, the bias current including a component that varies with temperature and a component that varies with process; and apparatus for providing the bias current to other transconductance circuits.
Claims19
A transconductance control circuit, comprising:
- a test transconductance circuit for providing an output current from a reference voltage;
- apparatus for deriving a bias current for the test transconductance circuit from the output current, the bias current including a component that varies with temperature and a component that varies with
- process, wherein the apparatus for deriving the bias current comprises apparatus for determining a difference current representing the difference between the output current and a reference current, the reference current including a component that varies with temperature, and a current amplifier for amplifying the difference current to produce the bias current;
- and
- apparatus for providing the bias current to other transconductance circuits.
2 more elements
A method of controlling transconductance of a transconductance circuit, comprising:
- producing an output current from a reference voltage using a test transconductance circuit;
- deriving a bias current for the test transconductance circuit from the output current, wherein the bias current includes a component that varies with temperature and a component that varies with wherein deriving the bias current comprises determining a difference current representing a difference between the output current and a reference current, the reference current including a component that varies with temperature, and amplifying the difference current to produce the bias current;
- and
- providing the bias current to other transconductance circuits.
1 more element
A power amplifier, comprising:
- a power transconductance circuit;
- a load impedance;
- and
- a gain control circuit, comprising:
- a test transconductance circuit for providing an output current from a reference voltage;
- apparatus for deriving a bias current for the transconductance circuit, the bias current including a component that varies with temperature and a component that varies with process, wherein the apparatus for deriving the bias current comprises apparatus for determining a difference current representing a difference between the output current and a reference current, the reference current including a component that varies with temperature, and a current amplifier for amplifying the difference current to produce the bias current;
- and apparatus for providing the bias current to the power transconductance circuit to control the gain of the power amplifier.
4 more elements
A power amplifier comprising:
- a power transconductance circuit;
- a load impedance;
- and
- a gain control circuit, comprising:
- a test transconductance circuit for providing an output current from a reference voltage;
- apparatus for subtracting the output current from a reference current to produce an error current, wherein the reference current includes a component that varies with temperature and a component independent of temperature and process;
- a current amplifier for amplifying the error current to produce the bias current;
- and a current mirror for providing the bias current to the power transconductance circuit to control the gain of the power amplifier;
- wherein the relative magnitudes of the component that varies with temperature and the component independent of temperature and process are selected such that the gain of the power amplifier is substantially independent of temperature and process.
6 more elements
A transconductance control circuit, comprising:
- a test transconductance circuit for producing an output current iref from a reference voltage Vref;
- apparatus for determining an error current representing a difference between the output current and a reference current;
- an amplifier for amplifying the error current to produce a bias voltage for the test transconductance circuit;
- and
- apparatus for providing the bias current to other transconductance circuits;
- wherein the transconductance of the transconductance circuit is maintained at substantially iref/Vref.
3 more elements
Dependencies are inferred from the claim text.