Adaptable voltage control for a variable gain amplifier
AssigneeBroadcom Corporation
InventorsMario Caresosa, Guangming Yin
Life of this patent
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Abstract
A method and apparatus for adaptively controlling a variable gain amplifier (VGA). The operation of the VGA is separated into a low gain mode and a high gain mode and the mode in which the VGA is currently operating in is adaptively sensed. A threshold voltage is compared to a control voltage of the VGA; if the VGA is currently operating in the low gain mode and the control voltage is higher than the threshold voltage, the VGA is switched from the low gain mode to the high gain mode; and if the VGA is currently operating in the high gain mode and the control voltage is lower than the threshold voltage, the VGA is switched from the high gain mode to the low gain mode.
Claims30
One or more circuits for controlling a variable gain amplifier (VGA) operable in a low gain mode and a high gain mode, wherein a level of gain when operating in one of the low gain mode and high gain mode is adjustable according to a control signal, the one or more circuits comprising:
- interface circuitry for sensing the operating mode of the variable gain amplifier;
- and
- a controller operably coupled to the interface circuitry, the controller operable to, at least, determine the current operating mode of the variable gain amplifier;
- if the current operating mode is the low gain mode,
- compare the control signal to a first threshold representing a relatively higher level of gain, and
- set a new operating mode of the variable gain amplifier to the high gain mode, if a level of gain represented by the control signal is greater than the level of gain represented by the first threshold;
- if the current operating mode is the high gain mode,
- compare the control signal to a second threshold representing a relatively lower level of gain, and
- set the new operating mode of the variable gain amplifier to the low gain mode, if the level of gain represented by the control signal is less than the level of gain represented by the second threshold;
- and make the current operating mode of the variable gain amplifier equal to the new operating mode.
An integrated circuit comprising:
- a variable gain amplifier (VGA) operable in a low gain mode and a high gain mode, wherein a level of gain when operating in one of the low gain mode and high gain mode is responsive to a control signal;
- comparator circuitry operable to compare the control signal to a first threshold representing a relatively higher level of gain and to a second threshold representing a relatively lower level of gain;
- control logic operable to, at least,
- determine a current operating mode of the variable gain amplifier;
- change the operating mode of the variable gain amplifier to the high gain mode, if the current operating mode is the low gain mode and a level of gain represented by the control signal is greater than the level of gain represented by the first threshold;
- and
- change the operating mode of the variable gain amplifier to be the low gain mode, if the current operating mode is the high gain mode and the level of gain represented by the control signal is less than the level of gain represented by the second threshold.
A communication system having a variable gain amplifier (VGA) operable in a low gain mode and a high gain mode, wherein a level of gain when operating in one of the low gain mode and the high gain mode is adjustable according to a control signal, the system comprising:
- at least one controller enabled to sense the operating mode of the variable gain amplifier, the at least one controller operable to, at least,
- in the low gain mode,
- compare the control signal to a first threshold representing a relatively higher level of gain, and
- if a level of gain represented by the control signal is greater than the level of gain represented by the first threshold, change the operating mode of the variable gain amplifier to the high gain mode;
- and in the high gain mode,
- compare the control signal to a second threshold representing a relatively lower level of gain, and
- if the level of gain represented by the control signal is less than the level of gain represented by the second threshold, change the operating mode of the variable gain amplifier to the low gain mode.
Dependencies are inferred from the claim text.