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US 2006/0049899 A1Published application
Tunable poly-phase filter and method for calibration thereof
AssigneeIntegration Associates Inc.
InventorHendricus De Ruijter
Life of this patent
Estimating the term…
Abstract
A resonator circuit is shown that is fabricated with substantially identical elements disposed symmetrically along an axis such that the circuit has a linear response to bias current. The alignment of the circuit permits multiple characteristics of the circuit to be calibrated.
Claims22
A resonator circuit, the circuit having a first phase stage comprised of:
- a first inverting transconductor (110) having an input and an output;
- a first non-inverting transconductor (120) having an input coupled to the output of the first inverting transconductor (110) to form a first circuit node (I) and an output coupled to the input of the first inverting transconductor (110) to form a second circuit node (Q);
- a second inverting transconductor (112) having an input and an output, where both the input and output are coupled to the first circuit node (I);
- a first capacitor (114) coupled to the first circuit node (I);
- a third inverting transconductor (122) having an input and an output, where both the input and output are coupled to the second circuit node (Q);
- and
- a second capacitor (124) coupled to the second circuit node;
- where the first inverting transconductor (110), the first capacitor (114) and the second inverting transconductor (112) are fabricated on a die substantially symmetrically to the first non-inverting transconductor (120), the second capacitor (124) and the third inverting transconductor (122) along an axis (A) of the die.
5 more elements
A method for calibrating a resonator circuit, the method comprising the steps of:
- fabricating a first phase stage of the resonator circuit on a die such that the first phase stage includes:
- a first inverting transconductor (110) having an input and an output,
- a first non-inverting transconductor (120) having an input coupled to the output of the first inverting transconductor (110) to form a first circuit node (I) and an output coupled to the input of the first inverting transconductor (120) to form a second circuit node (Q),
- a second inverting transconductor (112) having an input and an output, where both the input and output are coupled to the first circuit node (I),
- a first capacitor (114) coupled to the first circuit node (I),
- a third inverting transconductor (122) having an input and an output, where both the input and output are coupled to the second circuit node (Q), and
- a second capacitor (124) coupled to the second circuit node,
- such that the first inverting transconductor (110), the first capacitor (114) and the second inverting transconductor (112) are symmetrical to the first non-inverting transconductor (120), the second capacitor (124) and the third inverting transconductor (122) along an axis (A) of the die;
- providing a replica (412) to the first phase stage of the resonator circuit;
- adjusting a bias current (If) of the replica (412) such that a resonant frequency of the replica matches a reference frequency (Fres);
- scaling the bias current (If) of the replica (412) to produce a second bias current (kf*If) for biasing the first inverting transconductor (110) and the first non-inverting transconductor (120) of the first phase stage;
- and
- scaling the bias current (If) of the replica (412) to produce a third bias current (kbw*If) for biasing the second inverting transconductor (112) and the third non-inverting transconductor (122) of the first phase stage.
10 more elements
(canceled)
A poly-phase band-pass filter circuit, the circuit comprising first and second phase stages, where each phase stage comprises:
- a first inverting transconductor (110) having an input and an output;
- a first non-inverting transconductor (120) having an input coupled to the output of the first inverting transconductor to form a first circuit node (I) and an output coupled to the input of the first inverting transconductor to form a second circuit node (Q);
- a second inverting transconductor (112) having an input and an output, where both the input and output are coupled to the first circuit node (I);
- a first capacitor (114) coupled to the first circuit node (I);
- a third inverting transconductor (122) having an input and an output, where both the input and output are coupled to the second circuit node (Q);
- a second capacitor (124) coupled to the second circuit node (Q);
- a second non-inverting transconductor (230) having an input for receiving a first input voltage signal and an output coupled to the first circuit node (I);
- and
- a third non-inverting transconductor (240) having an input for receiving a second input voltage signal and an output coupled to the second circuit node (Q),
- where the first inverting transconductor (110), the first capacitor (114), the second inverting transconductor (112) and the second non-inverting transconductor (230) are fabricated on a die symmetrically to the first non-inverting transconductor (120), the second capacitor (124), the third inverting transconductor (122), and the third non-inverting transconductor (240) along an axis (C) of the die, and
- where the input of the second non-inverting transconductor (330) of the second phase stage is coupled to the first circuit node (I) of the first phase stage, and
- where the input of the third non-inverting transconductor (340) of the second phase stage is coupled to the second circuit node (Q) of the first phase stage;
- and
- the resonator circuit further comprises:
- a first feedback inverting transconductor (350) having an input coupled to the first circuit node (I′) of the second phase stage and an output coupled to the first circuit node of the first phase stage (I);
- and
- a second feedback inverting transconductor (360) having an input coupled to the second circuit node (Q′) of the second phase stage and an output coupled to the second circuit node (Q) of the first phase stage.
14 more elements
Dependencies are inferred from the claim text.