Charge Pump Filter Circuit Without Op-Amps or Large Capacitors
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Solution Overview
Problem
Current charge pump and filter circuits in phase-locked loop and clock data recovery circuits suffer from inefficiencies, requiring large capacitors and additional components like operational amplifiers, which introduce noise and increase circuit complexity.
Innovation Solution
A charge pump filtering circuit design that includes switches, capacitors, and voltage switching circuits, eliminating the need for resistors and operational amplifiers, allowing for smaller capacitors and simpler architecture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional charge pump and filter circuits are used, then filtering function is achieved, but circuit complexity increases due to additional components like operational amplifiers
Solution Approach 1:
The patent combines the charge pump circuit and filter circuit into a single integrated charge pump filtering circuit. The filter capacitors are directly connected to the charge pump switches, eliminating the need for separate operational amplifiers and reducing circuit complexity while maintaining the filtering function.
Solution Approach 2:
The circuit components serve multiple functions: the switches act as both charge pump elements and switching elements for the filter, and the capacitors provide both filtering and voltage storage functions. This multi-functionality reduces the total number of components needed.
2Reliability
If traditional charge pump and filter circuits are used, then filtering is achieved, but noise increases due to additional components
Solution Approach 1:
The patent removes the operational amplifiers from the traditional filter circuit design, extracting the noise-generating components while retaining the essential filtering function through the capacitor-switch network alone.
3Reliability
If traditional filter circuit with large capacitors is used, then filtering performance is maintained, but circuit area increases
Solution Approach 1:
The filter capacitors are integrated directly with the charge pump circuit nodes, sharing the same physical space and eliminating the need for separate filter sections. This integration reduces the overall circuit area while maintaining filtering performance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The proposed solution achieves smoother filtering voltages with reduced noise and circuit area, maintaining performance while simplifying the circuit design.
Implementation Method 1
The filter circuit includes a first capacitor, a second capacitor, and a first voltage switching circuit. The first capacitor is coupled between the first node and the ground terminal. The second capacitor is coupled between the first voltage switching circuit and the first node.
Data Source
AI summary
A charge pump filtering circuit includes a charge pump circuit and a filter circuit. The charge pump circuit includes a first switch and a second switch. The first switch and the second switch are coupled at a first node and are coupled between a power terminal and a ground terminal. The filter circuit includes a first capacitor, a second capacitor, and a first voltage switching circuit. The first capacitor is coupled between the first node and the ground terminal. The second capacitor is coupled between the first voltage switching circuit and the first node.