Variable gain amplifier
AssigneeCambridge Silicon Radio Limited
InventorHashem Zare-Hoseini
Life of this patent
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Abstract
A variable gain amplifier includes an integrator having an input, an output and a feedback loop connected between the input and output, a plurality of input chains connected in parallel between the amplifier input and the input of the integrator, each input chain including a resistor and a first switch and a plurality of second switches, each second switch connected between an intermediate node between the resistor and first switch of a respective input chain and the feedback loop of the integrator, wherein the resistance of the resistors in the input chains is scaled by a scaling factor with respect to one another and the on-resistances of the first and second switches connected to each intermediate node are scaled by the corresponding scaling factor.
Claims7
A variable gain amplifier comprising:
- an input voltage node;
- an integrator having an input, an output and a feedback loop;
- and
- a plurality of input chains connected in parallel between the input voltage node and the input of the integrator, each input chain including a resistor and a first switch connected in series;
- characterised in that:
- the resistor of each input chain is connected to the input voltage node;
- and
- the integrator feedback loop includes a plurality of second switches connected in parallel, each second switch connected to an intermediate node between the resistor and first switch of a respective input chain and coupled to the output of the integrator, wherein the resistance of the resistors in the input chains is scaled by a scaling factor with respect to one another and the on-resistances of the first and second switches connected to each intermediate node are scaled by the corresponding scaling factor.
Dependencies are inferred from the claim text.