Patent ID: 6538477
Filing Date: 2003-03-25
Classification: H03F

Abstract:
An input buffer circuit for use in a switched-capacitor circuit, said input buffer circuit comprising:a first amplifier configured for receiving an input voltage, said first amplifier comprising a first differential pair of transistors and a second pair of transistors comprising a first current mirror, wherein one of said first differential pair of transistors comprises a diode-connected arrangement to provide a first feedback loop; a second amplifier configured for providing a gain boosting function to said first amplifier, said second amplifier comprising a second differential pair of transistors and a third pair of transistors comprising a second current mirror, said second amplifier configured for driving said second pair of transistors of said first amplifier; and wherein said second amplifier and one transistor of said second pair of transistors comprises a second feedback loop, said second feedback loop operating within said first feedback loop such that said input buffer circuit operates as a single stage amplifier, and wherein said second amplifier provides gain-boosting to said first amplifier.