Invention Grant
- Patent Title: Loop filter with noise cancellation
- Patent Title (中): 具有噪声消除的环路滤波器
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Application No.: US11479513Application Date: 2006-06-30
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Publication No.: US08593216B2Publication Date: 2013-11-26
- Inventor: Gang Zhang
- Applicant: Gang Zhang
- Applicant Address: US CA San Diego
- Assignee: QUALCOMM Incorporated
- Current Assignee: QUALCOMM Incorporated
- Current Assignee Address: US CA San Diego
- Agent Ramin Mobarhan
- Main IPC: H03K5/00
- IPC: H03K5/00

Abstract:
A loop filter with noise cancellation includes first and second signal paths, an operational amplifier (op-amp), and a noise cancellation path. The first signal path provides a first transfer function (e.g., a lowpass response) for a first signal. The second signal path provides a second transfer function (e.g., an integration response) for a second signal. The second signal is a scaled version of, and smaller than, the first signal by a factor of alpha, where alpha is greater than one. A capacitor in the second signal path may be scaled smaller by a factor of alpha. The op-amp couples to the first and second signal paths and facilitates summing of signals from the first and second signal paths to generate a control signal having op-amp noise. The noise cancellation path couples to the op-amp and provides a noise cancellation signal used to cancel the op-amp noise in the control signal.
Public/Granted literature
- US20080001657A1 Loop filter with noise cancellation Public/Granted day:2008-01-03
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