US 8,299,844 B2 · System and circuitry to provide stable transconductance for biasing

Abstract

An amplifier system can include an input amplifier configured to receive an analog input signal and provide an amplified signal corresponding to the analog input signal. A tracking loop is configured to employ delta modulation for tracking the amplified signal, the tracking loop providing a corresponding output signal. A biasing circuit is configured to adjust a bias current to maintain stable transconductance over temperature variations, the biasing circuit providing at least one bias signal for biasing at least one of the input amplifier and the tracking loop, whereby the circuitry receiving the at least one bias signal exhibits stable performance over the temperature variations. In another embodiment the biasing circuit can be utilized in other applications.

Claims19

Dependent claims

An amplifier system comprising:

an input amplifier configured to receive an analog input signal and provide an amplified signal corresponding to the analog input signal;
a tracking loop configured to employ delta modulation for tracking the amplified signal, the tracking loop providing a corresponding output signal;
and
a biasing circuit configured to adjust a bias current to maintain stable transconductance over temperature variations, the biasing circuit providing at least one bias signal for biasing at least one of the input amplifier and the tracking loop, whereby circuitry receiving the at least one bias signal exhibits stable performance over the temperature variations.

1 more element

An integrated circuit comprising:

an input amplifier configured to receive an analog input signal and provide an amplified signal corresponding to the analog input signal;
a tracking loop configured to employ delta modulation for tracking the amplified signal, the tracking loop providing a corresponding output signal;
and
a bias generator for providing adaptive bias control that provides stabilization of transconductance over temperature for associated circuitry, the circuitry comprising:
a first arrangement of transistors configured as a first current mirror portion, the first current mirror portion being connected to a first reference voltage;
and
a second arrangement of transistors and a resistor configured as a second current mirror portion having a non-linear characteristic to provide a bias current through the resistor that is inversely proportional to mobility, the first current mirror portion being connected with the second current mirror portion between the first reference voltage and a second reference voltage and being arranged in a feedback relationship to stabilize the bias current through the resistor,
a bias voltage being provided from at least one of the first current mirror portion and the second current mirror portion based on the bias current,
wherein each of the input amplifier and the tracking loop is biased by the bias voltage generated by the bias generator.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application

12/407,348Filed 19 Mar 2009 · continuation in part

Priority

29 Sep 2005

Published

US 2009/0205436 A120 Aug 2009

Granted

30 Oct 2012

Term ends

Not estimatedThe source records don’t support an estimate.

Classification3 codes

G01L 19/086
Means for indicating or recording, e.g. for remote indication: for remote indication
G01L 1/2256
Measuring circuits therefor: involving digital counting
G01L
Measuring force, stress, torque, work, mechanical power, mechanical efficiency, or fluid pressure

Family

Application60/721,649Us provisional application · filed 29 Sep 2005

Application11/537,488Parent of this continuation-in-part · filed 29 Sep 2006

US 2009/0205436 A1Pre-grant publication · published 20 Aug 2009

US 7,562,581 B2Parent of this continuation-in-part

US 2007/0186668 A1Published application

US 8,299,844 B2This patent

From the US filing history. Foreign family members aren’t listed.

System and circuitry to provide stable transconductance for biasing

Life of this patent

System and circuitry to provide stable transconductance for biasing

Life of this patent

Abstract

Claims19