US 7,068,108 B2Granted

Amplifier apparatus and method

AssigneeTexas Instruments Incorporated

InventorsGonggui Xu, Haydar Bilhan

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Abstract

An amplifier apparatus having a gain programmable in discrete increments includes: (a) an operational amplifier having a first and second input and an output; (b) a feedback circuit between the output and the second input; (c) a reference signal source and supply circuit coupled with the first input; (d) a first resistor network coupled between a first signal locus and the first input conveying a first input signal to the first input and including a first plurality of parallel-connected first resistors; selected first resistors being independently coupled in a first connecting with the first input; (e) a second resistor network coupled between a second signal locus and the second input conveying a second input signal to the second input and including a second plurality of parallel-connected second resistors; selected second resistors being independently coupled in a second connecting with the second input.

Claims20

Dependent claims

An amplifier apparatus having a gain;

said gain being programmable to various values in discrete increments;
the apparatus comprising:
(a) an operational amplifier device having a first input locus for receiving a first signal, having a second input locus for receiving a second signal and having an output locus for presenting an output signal;
(b) a feedback circuit coupled between said output locus and said second input locus;
(c) a reference signal source coupled with said first input locus via a supply circuit for presenting a reference signal to said first input locus;
(d) a first resistor network coupled between a first signal locus and said first input locus;
said first resistor network conveying a first input signal from said first signal locus to said first input locus;
said first resistor network comprising a first plurality of parallel-connected first resistors;
selected first resistors of said first plurality of parallel-connected resistors being independently switchingly coupled for independently selectable inclusion in a first connecting of said first signal locus with said first input locus;
(e) a second resistor network coupled between a second signal locus and said second input locus;
said second resistor network conveying a second input signal from said second signal locus to said second input locus;
said second resistor network comprising a second plurality of parallel-connected second resistors;
selected second resistors of said second plurality of parallel-connected resistors being independently switchingly coupled for independently selectable inclusion in a second connecting of said second signal locus with said second input locus;
said gain being established by at least one of said supply circuit and said selected first resistors, and said feedback circuit and said selected second resistors.

11 more elements

A method for buffering a signal with a programmable gain;

said gain being programmable to various values in discrete increments;
the method comprising the steps of:
(a) in no particular order:
(1) providing an operational amplifier device having a first input locus for receiving a first signal, having a second input locus for receiving a second signal and having an output locus for presenting an output signal;
(2) providing a feedback circuit coupled between said output locus and said second input locus;
(3) providing a reference signal source coupled with said first input locus via a supply circuit for presenting a reference signal to said first input locus;
(4) providing a first resistor network coupled between a first signal locus and said first input locus;
said first resistor network comprising a first plurality of parallel-connected first resistors;
selected first resistors of said first plurality of parallel-connected resistors being independently switchingly coupled for independently selectable inclusion in a first connecting of said first signal locus with said first input locus;
and
(5) providing a second resistor network coupled between a second signal locus and said second input locus;
said second resistor network comprising a second plurality of parallel-connected second resistors;
selected second resistors of said second plurality of parallel-connected resistors being independently switchingly coupled for independently selectable inclusion in a second connecting of said second signal locus with said second input locus;
(f) in no particular order:
(1) switchingly coupling said selected first resistors and operating said first resistor network to convey a first input signal from said first signal locus to said first input locus;
and
(2) switchingly coupling said selected second resistors and operating said second resistor network to convey a second input signal from said second signal locus to said second input locus;
said gain being established by at least one of said supply circuit and said selected first resistors;
and said feedback circuit and said selected second resistors.

16 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/958,507Filed 5 Oct 2004 · us provisional application
Priority: 9 Jan 2004
Published: US 2005/0151590 A114 Jul 2005
Granted: 27 Jun 2006
Term ends: Not estimatedThe source records don’t support an estimate.

Classification2 codes

H03G 1/0088
Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal: using discontinuously variable…
H03G
Control of amplification