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US 2011/0086594 A1Published application
Providing A Temperature Dependent Bias For A Device
AssigneeJavelin Semiconductor, Inc.
InventorJames Francis McElwee
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Abstract
In one embodiment, a method includes generating a first current in a bias current circuit and biasing an amplifier with the first current when the amplifier is operating in a first temperature range, and generating a second current in the bias current circuit and biasing the amplifier with the second current when the amplifier is operating in a second temperature range. These two currents may correspond to different profiles with respect to temperature, to maintain substantial linearity of the amplifier over the temperature ranges.
Claims20
A method comprising:
- generating a first current in a bias current circuit and biasing an amplifier with the first current when the amplifier is operating in a first temperature range, the first current corresponding to a first profile with respect to temperature;
- and
- generating a second current in the bias current circuit and biasing the amplifier with the second current when the amplifier is operating in a second temperature range, the second current corresponding to a second profile with respect to temperature.
An apparatus comprising:
- a first differential pair including a first metal oxide semiconductor field effect transistor (MOSFET) and a second MOSFET, the first and second MOSFETs having first terminals coupled to a first current source, the first MOSFET gated by a first temperature dependent voltage and the second MOSFET gated by a second temperature dependent voltage;
- and
- a second differential pair including a third MOSFET and a fourth MOSFET, the third and fourth MOSFETs having first terminals coupled to a second current source, the third MOSFET gated by the second temperature dependent voltage and the fourth MOSFET gated by the first temperature dependent voltage, wherein the second and fourth MOSFETs are to provide an output current according to a multi-level profile with respect to temperature.
A system comprising:
- a transceiver to receive baseband signal information from a baseband processor and to output a radio frequency (RF) signal;
- an amplifier to amplify the RF signal to output an amplified RF signal;
- and
- a current generator to generate a bias current for the amplifier, the bias current being temperature dependent and having at least a first profile in a first temperature range and a second profile in a second temperature range, to reduce variation with respect to temperature of a gain characteristic curve of the amplifier and maintain substantial linearity.
1 more element
Dependencies are inferred from the claim text.