Analog loop filter systems, apparatus, and methods
AssigneeSemtech Corporation
InventorEric Vandel
Life of this patent
Estimating the term…
Abstract
Described herein is a distributed analog loop filter that can be employed in a phase locked loop or a delay locked loop. A circuit block of the distributed analog loop filter includes at least two parallel equivalent circuit elements. The parallel equivalent circuit elements each have an input line. The input lines for each of the parallel equivalent circuit elements are activated sequentially, one after the other. The parallel equivalent circuit elements have sequentially produced outputs that are also activated sequentially, one after another. The parallel equivalent circuit elements extend the tuning range of distributed analog filter while reducing noise associated with the distributed analog filter.
Claims20
A voltage controlled oscillator, comprising:
- a variable capacitor comprising N progressively switched capacitors;
- and
- N control lines corresponding to the N progressively switched capacitors respectively;
- wherein,
- N represents an integer number having a value of two or more.
An analog loop filter, comprising:
- a circuit block comprising N parallel equivalent circuit elements, wherein N represents an integer having a value of at least two;
- N input lines coupled to the N parallel equivalent circuit elements respectively, wherein the N parallel equivalent circuit elements are activated sequentially;
- and
- N sequentially produced outputs corresponding to the N parallel equivalent circuit elements respectively.
A method, comprising:
- driving N inputs to N parallel equivalent circuit elements in a circuit block of an analog loop filter respectively,
- wherein the driving includes sequentially driving the N inputs to reduce noise in the analog loop filter,
- wherein N is at least 2.
Dependencies are inferred from the claim text.