Distortion improvement in amplifiers
AssigneeElantec Semiconductor, Inc.
InventorBarry Harvey
Life of this patent
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Abstract
An improved amplifier includes an input stage differential amplifier (100) with an output forming a gain node (102), an output stage buffer (104) having an input connected to the gain node (102), a compensation capacitor (106) connected from the gain node (102) to ground, and a correction amplifier (200) with a first input connected to the output of the output stage buffer (104), a second input connected to the input of the output stage buffer (104), and having an output connected to the gain node (102), the correction amplifier further including a correction capacitor (304) connected between the input and output of the output stage buffer (104). The correction capacitor (304) preferably has a capacitance value (C′) set equal to the capacitance (Ccomp) of the compensation capacitor (106).
Claims9
An amplifier comprising:
- an input differential amplifier (100) having a first input providing an inverting input (−) to the amplifier, and a second input providing a noninverting input (+) to the amplifier, and having an output forming a gain node;
- a compensation capacitor (106) having a first terminal coupled to the gain node and having an output coupled to a first power supply terminal;
- an output buffer amplifier (104) having an input coupled to the gain node and an output forming the output of the amplifier;
- and
- a correction amplifier (200) having a first input coupled to the output of the output buffer amplifier, a second input coupled to the gain node, and an output coupled to the gain node, wherein the correction amplifier comprises:
- a correction capacitor (304) having a first terminal coupled to the output of the output buffer amplifier, and a second terminal coupled to the gain node.
Dependencies are inferred from the claim text.