Variable-gain amplifier circuit and method of changing gain amplifier path
AssigneeNovatek Microelectronics Corp.
InventorKuo-Yu Chou
Life of this patent
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Abstract
A variable-gain amplifier circuit and a method of changing gain amplifier paths are provided for receiving and amplifying an image sensing signal. The variable-gain amplifier circuit includes variable path and gain amplifier circuits. According to the amplification factor for the image sensing signal, the gain amplifier paths in the variable path and gain amplifier circuits are changed based on a control signal, so as to achieve the appropriate construction of the variable-gain amplifier circuit. The image sensing signal generates the required image result through appropriate numbers of variable gain amplifiers, thereby decreasing the power consumption of the circuit and reducing the design requirement of the circuit.
Claims14
A variable-gain amplifier circuit, for receiving and amplifying an image sensing signal, comprising:
- a first variable path and gain amplifier circuit, having a first variable gain amplifier (VGA), for making the signal at the output end to be the signal at the input end either being amplified by the first VGA or bypassing without being amplified by the first VGA according to a first control signal;
- a second variable path and gain amplifier circuit, having a second VGA, for making the signal at the output end to be the signal at the input end either being amplified by the second VGA or bypassing without being amplified by the second VGA according to a second control signal;
- and
- a controller coupled to the first and the second variable path and gain amplifier circuits, generating the first control signal and the second control signal according to a digital signal of an analog-to-digital converter, so as to control paths in the first and second variable path and gain amplifier circuits,
- wherein the output end of the variable-gain amplifier circuit is coupled to the analog-to-digital converter, and when the signal at the output end of the variable-gain amplifier circuit is the image sensing signal being amplified by the first VGA and the second VGA, the analog-to-digital converter reduces the resolution of the output digital signal.
A variable-gain amplifier circuit, for receiving and amplifying an image sensing signal, comprising:
- a plurality of variable path and gain amplifier circuits connected in series, wherein each of the variable path and gain amplifier circuits comprises a VGA, and makes the signal at the output end to be the signal at the input end either being amplified by the VGA or bypassing without being amplified by the VGA according to a control signal;
- and
- a controller coupled to the variable path and gain amplifier circuits, generating the control signals according to a digital signal of an analog-to-digital converter, so as to control paths in the variable path and gain amplifier circuits,
- wherein the output end of the variable-gain amplifier circuit is coupled to the analog-to-digital converter, and when the signal at the output end of the variable-gain amplifier circuit is the image sensing signal being amplified by the first VGA and the second VGA, the analog-to-digital converter reduces the resolution of the output digital signal.
A variable-gain amplifier circuit, for receiving and amplifying an image sensing signal, comprising:
- a first VGA;
- a second VGA;
- and
- a path changing circuit, coupled to the first VGA and the second VGA, wherein the path changing circuit makes the signal at the output end of the variable-gain amplifier circuit to be the image sensing signal being amplified by the first VGA or the second VGA, or bypassing without being amplified by both the first and the second VGAs, or being amplified by both the two VGAs according to a control signal;
- and
- a controller coupled to the path changing circuit, generating the control signal according to a digital signal output of an analog-to-digital, so as to control the path changing circuit,
- wherein the output end of the variab1e-gain amplifier circuit is coupled to the analog-to-digital converter, and when the signal at the output end of the variable-gain amplifier circuit is the image sensing signal being amplified by the first VGA and the second VGA, the analog-to-digital converter reduces the resolution of the output digital signal.
A method of changing the gain amplifier paths, for receiving and amplifying an image sensing signal, comprising:
- providing a first VGA and a second VGA;
- making an intermediate signal to be the image sensing signal either being amplified by the first VGA or bypassing without being amplified by the first VGA according to a first control signal;
- making an output signal to be the intermediate signal either being amplified by the second VGA or bypassing without being amplified by the second VGA according to a second control signal,
- wherein the first control signal and the second control signal are generated according to a digital signal output of an analog-to-digital converter coupled to the output end of the variable-gain amplifier circuit, so as to control the gain amplifier paths, and when the signal at the output end of the variable-gain amplifier circuit is the image sensing signal being amplified by the first VGA and the second VGA. the analog-to-digital converter reduces the resolution of the output digital signal.
A method of changing the gain amplifier paths, for receiving and amplifying an image sensing signal, comprising:
- providing a first VGA and a second VGA;
- and
- making an output signal to be the image sensing signal at the input end being amplified by the first VGA or the second VGA, or bypassing without being amplified both the first and second VGAs, or being amplified by both the VGAs according to a control signal,
- wherein the control signal is generated according to a digital signal of an analog-to-digital converter coupled to the output end of the variable-gain amplifier circuit, so as to control the gain amplifier paths, and when the signal at the output end of the variable-gain amplifier circuit is the image sensing signal being amplified by the first VGA and the second VGA, the analog-to-digital converter reduces the resolution of the output digital signal.
Dependencies are inferred from the claim text.