Method and Implementation for Accurate Gain-Bandwidth Product Tuning
AssigneeFuturewei Technologies, Inc.
InventorsHomero Luz Guimaraes, Matthew Richard Miller
Life of this patent
Estimating the term…
Abstract
Method and implementation of gain-bandwidth product (GWB) tuning are disclosed. In an embodiment an operational amplifier (opamp) includes an input stage of the opamp including a differential device pair coupled to a tail device and configured to be responsive to a differential input signal for conducting a first current and an output stage of the opamp including a class AB interface stage circuit and a pair of output devices connected to the class AB interface stage circuit, wherein a first constant gm bias circuit is coupled to an input terminal of the class AB interface stage circuit.
Claims22
An operational amplifier (opamp) comprising:
- an input stage of the opamp including a differential device pair coupled to a tail device and configured to be responsive to a differential input signal for conducting a first current;
- an output stage of the opamp including a class AB interface stage circuit and a pair of output devices connected to the class AB interface stage circuit;
- and
- a first bias circuit coupled to an input of the class AB interface stage circuit, wherein the first bias circuit is configured to provide a first input signal to the class AB interface stage circuit such that an output device of the pair of output devices comprises a substantially constant transconductance, and wherein the first bias circuit comprises a current generating portion, a first current mirror and a second current mirror.
(canceled)
A filter comprising:
- a first order section;
- and
- a second order section, wherein the second order section comprises an operational amplifier (opamp), the operational amplifier comprising:
- an input stage of the opamp including a differential device pair coupled to a tail device and configured to be responsive to a differential input signal for conducting a first current;
- an output stage of the opamp including a class AB interface stage circuit and a pair of output devices connected to the class AB interface stage circuit;
- and
- a first bias circuit coupled to an input of the class AB interface stage circuit, wherein the first bias circuit is configured to provide a first input signal to the class AB interface stage circuit such that an output device of the pair of output devices comprises a substantially constant transconductance, and wherein the second order section is a Tow-Thomas Biquad Filter.
(canceled)
16-20. (canceled)
An operational amplifier (opamp) comprising:
- an input stage of the opamp including a differential device pair coupled to a tail device and configured to be responsive to a differential input signal for conducting a first current;
- and
- an output stage of the opamp including a class AB interface stage circuit and a pair of output devices connected to the class AB interface stage circuit,
- wherein a first substantially constant transconductance bias circuit is coupled to an input of the class AB interface stage circuit, and wherein the first constant transconductance bias circuit comprises a ΔVgs current generating portion, a first current mirror and a second current mirror.
A filter comprising:
- a first order section;
- and
- a second order section, wherein the second order section comprises an operational amplifier (opamp), wherein the operational amplifier comprises:
- an input stage of the opamp including a differential device pair coupled to a tail device and configured to be responsive to a differential input signal for conducting a first current;
- and
- an output stage of the opamp including a class AB interface stage circuit and a pair of output devices connected to the class AB interface stage circuit,
- wherein a first substantially constant transconductance bias circuit is coupled to an input of the class AB interface stage circuit, and
- wherein the second order section is a Tow-Thomas Biquad Filter.
Dependencies are inferred from the claim text.