Charge Pump Circuit Reducing Glitches in Clock Data Recovery
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Solution Overview
Problem
Existing clock data recovery (CDR) devices are inadequate for high-data communication applications, particularly due to issues with charge glitches and susceptibility to parasitic effects of capacitors.
Innovation Solution
A charge pump module is introduced, utilizing early and late signals as differential input control signals, with a first and second switch controlling the direction of the charge pump current, and an output resistor generating a charge pump current, which reduces charge glitches and minimizes parasitic effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing CDR devices are used, then basic clock data recovery function is provided, but charge glitches occur and susceptibility to parasitic effects increases
Solution Approach 1:
The charge pump circuit is segmented into multiple independent switches (first switch, second switch, third switch, fourth switch) that operate in a coordinated sequence. This segmentation allows precise control of charge flow paths, enabling the circuit to reduce charge glitches by ensuring clean transitions between charging and discharging phases, thereby improving reliability while minimizing harmful charge anomalies.
Solution Approach 2:
The charge pump circuit employs dynamic switching control where the switches are activated in a specific sequence based on the operational phase. The first and second switches control charging phases while the third and fourth switches control discharging phases, creating a dynamic response that adapts to real-time circuit conditions. This dynamic operation reduces susceptibility to parasitic effects by maintaining optimal charge flow control throughout the operational cycle.
2Productivity
If high-data communication applications are implemented, then data transfer capability is improved, but existing CDR devices become inadequate
Solution Approach 1:
The charge pump circuit maintains continuous useful action through its multi-switch architecture that ensures uninterrupted charge and discharge cycles. The coordinated operation of the four switches creates a continuous rhythm of charging and discharging the loop filter capacitor, which stabilizes the VCO frequency output. This continuous operation is essential for high-data communication applications where uninterrupted clock recovery is critical for maintaining data transfer integrity and reliability.
Solution Approach 2:
The circuit dynamically adjusts operational parameters including charge pump current magnitude, switching frequency, and duty cycle to match the demands of high-data communication applications. By changing these parameters in response to application requirements, the CDR device maintains adequacy and reliability even as data transfer capability increases to meet high-bandwidth demands.
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 solution reduces charge glitches and improves the robustness of CDR devices, making them less susceptible to parasitic effects, thereby enhancing their performance in high-data communication applications.
Implementation Method 1
A first switch and a second switch are used for controlling the direction of the charge pump current
Implementation Method 2
The output voltage of the first switch and the second switch is used in conjunction with a resistor to generate a charge pump current
Data Source
AI summary
The present invention is directed to electrical circuits. More specifically, embodiments of the present invention provide a charge pump, which can be utilized as a part of a clock data recovery device. Early and late signals are used as differential switching voltage signals in the charge pump. The first switch and a second switch are used for controlling the direction of the current flowing into the loop filter. Input differential voltages to the switches are being generated with an opamp negative feedback loop. The output voltage of the first switch and the second switch is used in conjunction with a resistor to generate a charge pump current. There are other embodiments as well.