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US 10,644,664 B2Granted
Offset cancellation scheme
AssigneeTexas Instruments Incorporated
InventorsJikai Chen, Gerd Schuppener, Yanli Fan
Life of this patent
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Abstract
An offset cancellation circuit and method are provided where successive stages of cascaded amplifiers are operated in a saturated state. Biasing is provided, by a feedback amplifier, connected in a feedback loop for each cascaded amplifier, so as to be responsive, in a non-saturated state, to the input of an associated amplifier stage operating in the saturated state.
Claims20
An offset cancellation circuit for a multi-stage differential amplifier, comprising:
- at least three differential amplifier stages (amplifier stages), each with a differential input (input) and a differential output (output), cascaded together with an output of an amplifier stage other than a last amplifier stage connected to an input of a next amplifier stage;
- and
- at least two offset cancellations loops, each including a respective amplifier stage (collectively, the included amplifier stages), and each coupled from an output of the associated amplifier stage back to the input of a first of the included amplifier stages (the first of the included amplifier stages designated a cancellation amplifier stage), the offset cancellation loops including:
- offset cancellation circuitry coupled to receive the differential outputs of the included amplifier stages, and including a differential output (output) coupled to the input of the cancellation amplifier stage,
- the offset cancellation circuitry configured to cancel offset at the input of the cancellation amplifier stage.
2 more elements
A multi-stage differential amplifier circuit, comprising:
- at least three differential amplifier stages (amplifier stages), each with a differential input (input) and a differential output (output), cascaded together with an output of an amplifier stage other than a last amplifier stage connected to an input of a next amplifier stage;
- and
- at least two offset cancellations loops, each including a respective amplifier stage (collectively, the included amplifier stages), and each coupled from an output of the associated amplifier stage to the input of a first of the included amplifier stages (the first of the included amplifier stages designated a cancellation amplifier stage), each offset cancellation loop including:
- amplification circuitry coupled to receive the differential outputs of the included amplifier stages, and including a differential input (input) coupled to the output of the associated amplifier stage, and a differential output (output) coupled to the input of the cancellation amplifier stage;
- the amplification circuitry configured to cancel offset at the input of the cancellation amplifier stage.
2 more elements
A multi-stage differential amplifier circuit, comprising:
- at least three differential amplifier stages (amplifier stages), each with a differential input (input) and a differential output (output), cascaded together with an output of an amplifier stage other than a last amplifier stage connected to an input of a next amplifier stage;
- and
- for at least two of the amplifier stages (collectively, the included amplifier stages), amplification circuitry coupled between the differential outputs of each of the included amplifier stages, and the input of a first of the included amplifier stage;
- the amplification circuitry including a differential input (input) coupled to the outputs of each of the included amplifier stages, and a differential output (output) coupled to the input of the first of the included amplifier stage.
1 more element
Dependencies are inferred from the claim text.