US 10,263,582 B1 · Variable gain amplifier with gain-based compensation

Abstract

The present disclosure describes variable gain amplifiers with gain-based compensation. In some embodiments, a variable gain amplifier (VGA) includes a gain stage, an output stage, a compensation stage, and a capacitor coupled between respective outputs of the gain stage and compensation stage. A gain of the VGA is configured, based on a gain setting, to amplify signals received by the variable gain amplifier. A gain of the compensation stage is configured, based on the gain setting, to alter an effective capacitance of the capacitor, which is applied to the output of the gain stage for compensation of the VGA. By altering the effective capacitance based on the gain setting of the VGA, compensation capacitance is adjusted continuously with changes in the gain setting and at a similar resolution. In various embodiments, the continuous adjustment of the compensation capacitance across different gain levels prevents discontinuities in amplifier compensation.

Claims20

Dependent claims

A method for amplifying an analog signal read from a magnetic media disk, the method comprising:

receiving the analog signal from a read head configured to generate the analog signal based on digital data stored on the magnetic media disk;
determining a gain setting for a variable gain amplifier having a gain stage, an output stage, a compensation stage coupled to an output of the output stage, and a capacitor coupled between an output of the gain stage and an output of the compensation stage;
configuring, based on the gain setting, a gain of the variable gain amplifier by which to amplify a signal;
configuring, based on the gain setting, a gain of the compensation stage to alter an effective capacitance of the capacitor;
compensating, at the output of the gain stage, the variable gain amplifier with the effective capacitance of the capacitor;
and
amplifying the signal at the configured gain with the compensated gain stage of the variable gain amplifier.

4 more elements

A data storage apparatus comprising:

a media disk configured to store digital data;
a read head configured to generate an analog signal based on the digital data stored on the media disk;
an analog front-end comprising:
a variable gain amplifier that includes (i) a gain stage configured to amplify the analog signal to provide an amplified analog signal, (ii) an output stage configured to drive an output of the variable gain amplifier, (iii) a compensation stage coupled to an output of the output stage, and (iii) a capacitor disposed between an output of the gain stage and an output of the compensation stage;
an automatic gain controller configured to:
determine a gain setting for the variable gain amplifier;
set, based on the gain setting, a gain of the variable gain amplifier by which to amplify the analog signal;
selectively set, based on the gain setting, a gain of the compensation stage to alter an effective capacitance of the capacitor;
and
apply the effective capacitance to the output of the gain stage to compensate the variable gain amplifier;
an analog-to-digital converter configured to convert the amplified analog signal to a digital signal;
and
a digital processor configured to decode, based on the digital signal, the digital data stored on the media disk.

10 more elements

A System-on-Chip (SoC) for processing signals read from a magnetic media disk, the SoC comprising:

an input configured to receive an analog signal from a magnetic media read head;
a variable gain amplifier configured to amplify the analog signal, the variable amplifier including:
a gain stage configured to amplify the analog signal to provide an amplified analog signal;
an output stage configured to drive a variable resistor by which gain of the variable gain amplifier is selectably configurable;
and
a compensation stage having an output coupled to a variable capacitor that is coupled to an output of the gain stage;
an analog-to-digital converter configured to convert the amplified analog signal to a digital signal;
an output configured to transmit the digital signal;
and
a gain controller configured to:
adjust, based on the digital signal, a gain setting of the variable gain amplifier via the variable resistor;
and
adjust, based on the gain setting of the gain stage, a gain setting of the compensation stage to alter an effective capacitance of the variable capacitor;
and
apply, to the output of the gain stage, the effective capacitance of the variable capacitor to compensate the variable gain amplifier.

12 more elements

Dependencies are inferred from the claim text.

Variable gain amplifier with gain-based compensation

Life of this patent

Variable gain amplifier with gain-based compensation

Life of this patent

Abstract

Claims20