Method for increasing active inductor operating range and peaking gain
AssigneeXilinx, Inc.
InventorsJinyung Namkoong, Wenfeng Zhang, Parag Upadhyaya
Life of this patent
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Abstract
Methods and apparatus are described for a differential active inductor load for inductive peaking in which cross-coupled capacitive elements are used to cancel out, or at least reduce, the limiting effect of the gate-to-drain capacitance (Cgd) of transistors in the active inductor load. The cross-coupled capacitive elements extend the range over which the active inductor load behaves inductively and increase the quality factor (Q) of each active inductor. Therefore, the achievable inductive peaking of the load is significantly increased, which leads to providing larger signal swing across the load for a given power or, alternatively, lower power for a given signal swing.
Claims22
1-13. (canceled)
A method of distributing one or more periodic signals in a programmable integrated circuit (IC), comprising:
- driving the one or more periodic signals on a plurality of signal net pairs routed throughout the programmable IC and coupled to a plurality of configurable logic blocks in the programmable IC;
- and
- loading a differential periodic signal in the one or more periodic signals with an active inductor load configured to exhibit inductive peaking in a frequency band comprising at least a frequency of the differential periodic signal, wherein the active inductor load comprises:
- a pair of active inductors, each active inductor comprising a transistor and a resistor electrically coupled to the transistor;
- and
- a pair of cross-coupled capacitive elements electrically coupled to the pair of active inductors.
(canceled)
A programmable integrated circuit (IC) comprising:
- a plurality of configurable logic blocks;
- and
- a clock distribution system coupled to the plurality of configurable logic blocks via a plurality of signal net pairs and configured to distribute one or more periodic signals throughout the programmable IC via the plurality of signal net pairs, wherein at least one of the signal net pairs is terminated with an active inductor load comprising:
- a pair of active inductors, each active inductor comprising a transistor and a resistor electrically coupled between a gate and a drain of the transistor, wherein a resistance of the resistor in each active inductor is greater than an inverse of a transconductance of the transistor in each active inductor;
- and
- a pair of cross-coupled capacitive elements electrically coupled to the pair of active inductors.
Dependencies are inferred from the claim text.