Body biasing device and operational amplifier thereof
AssigneeAnpec Electronics Corporation
InventorsWen-Yen Chen, Ming-Hung Chang
Life of this patent
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Abstract
A body biasing device for an amplifier which has a P-type differential pair and outputs an output signal at an output node according to a differential input signal pair is disclosed. The body biasing device includes a detection unit coupled to the operational amplifier for detecting a detected voltage related to the differential input signals and accordingly outputting a control signal; and a selection unit coupled to the detection unit and the operational amplifier for outputting a body bias to the P-type differential pair according to the control signal.
Claims22
A body biasing device for an operational amplifier which has a P-type differential pair and outputs an output signal at an output node according to a differential input signal pair, comprising:
- a detection unit coupled to the operational amplifier for detecting a detected voltage related to the differential input signal pair and accordingly outputting a control signal;
- and
- a selection unit coupled to the detection unit and the operational amplifier for outputting a body bias to the P-type differential pair according to the control signal;
- wherein the P-type differential pair comprising:
- a first P-type transistor comprising a gate coupled to a first differential input, a source coupled to a current source, a drain coupled to an output stage circuit, and a body coupled to the selection unit;
- and
- a second P-type transistor comprising a gate coupled to a second differential input, a source coupled to the current source, a drain coupled to the output stage circuit, and a body coupled to the selection unit;
- wherein the detection unit is coupled to the gate of the first P-type transistor for detecting the detected voltage.
An operational amplifier, comprising:
- an output stage circuit for receiving a differential output signal pair and accordingly outputting an output signal at an output node;
- a P-type differential pair for receiving a differential input signal pair and accordingly outputting the differential output signal pair, comprising:
- a first P-type transistor comprising a gate coupled to a first differential input, a source coupled to a current source, a drain coupled to the output stage circuit, and a body coupled to a body bias;
- and
- a second P-type transistor comprising a gate coupled to a second differential input, a source coupled to the current source, a drain coupled to the output stage circuit, and a body coupled to the body bias;
- and
- a body biasing device comprising:
- a detection unit, coupled to the gate of the first P-type transistor, for detecting a detected voltage related to the differential input signal pair to output a control signal;
- and
- a selection unit coupled to the detection unit for outputting the body bias according to the control signal.
Dependencies are inferred from the claim text.