High linearly wigig baseband amplifier with channel select filter
AssigneeTensorcom, Inc.
InventorsZaw Soe, Kevin Jing, Steve Gao
Life of this patent
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Abstract
A circuit comprises a Sallen-Key filter, which includes a source follower that implements a unity-gain amplifier; and a programmable-gain amplifier coupled to the Sallen-Key filter. The circuit enables programmable gain via adjustment to a current mirror copying ratio in the programmable-gain amplifier, which decouples the bandwidth of the circuit from its gain settings. The programmable-gain amplifier can comprise a differential voltage-to-current converter, a current mirror pair, and programmable output gain stages. The Sallen-Key filter and at least one branch in the programmable-gain amplifier can comprise transistors arranged in identical circuit configurations.
Claims16
A circuit comprising:
- a Sallen-Key filter comprising a source follower that implements a unity-gain amplifier;
- and
- a programmable-gain amplifier coupled to the Sallen-Key filter, the circuit configured to provide programmable gain via adjustment to a current mirror copying ratio in the programmable-gain amplifier to decouple bandwidth of the circuit from its gain settings.
A method for avoiding linearity dependence on operating region of transistors in an amplifier in a Sallen-Key filter, comprising:
- employing a source follower in the Sallen-Key filter to provide unity gain, the source follower comprising an active device and a load device;
- and
- selecting a DC level of an input signal to the Sallen-Key filter to ensure adequate headroom of at least one of the load device and devices in a current-mirror pair employed as a programmable-gain amplifier.
A method for fabricating an integrated circuit, comprising:
- designing a transistor layout comprising an array of unit devices, the transistor layout to be common to a Sallen-Key filter and at least a programmable-gain amplifier;
- sizing the transistors in the transistor layout to provide for a common unit device size and current density;
- generating a design of the Sallen-Key filter and the programmable-gain amplifier to each include the transistor layout;
- and
- fabricating the Sallen-Key filter and the programmable-gain amplifier based on the design.
Dependencies are inferred from the claim text.