Integrated EMI Filter and Line Conditioning Module
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Solution Overview
Problem
Existing DC/DC converters face challenges in efficiently operating over wide input voltage ranges due to the need for additional components like EMI filters, boost converters, and transient limiters, which compromise efficiency, increase volume, and raise costs.
Innovation Solution
An integrated EMI filter and line-conditioning (EMI-LC) circuit that includes a passive differential mode EMI filter, a boost converter, and a transient limiter, with a control circuit that dynamically enables or disables these components based on input voltage levels, allowing the circuit to function as a passive filter during steady-state operation and switch to active modes for voltage regulation during transients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate EMI filter, boost converter, and transient limiter modules are used to handle wide input voltage ranges, then the DC/DC converter can maintain EMC compliance and operate over wide voltage ranges, but the overall device volume, component count, and cost increase
Solution Approach 1:
The patent combines the EMI filter, boost converter, and transient limiter into a single integrated module that processes input voltage conditions simultaneously. The common inductor and capacitor components serve multiple functions: the inductor provides both EMI filtering and boost conversion, while the capacitor serves both filtering and transient limiting purposes. This merging eliminates the need for separate modules for each function.
Solution Approach 2:
The integrated module employs universal components that perform multiple functions. The differential mode inductor and capacitor are designed to operate in both EMI filtering mode and voltage regulation mode (boost or transient limiting). The control circuit dynamically switches between operating modes based on input voltage conditions, allowing the same hardware to adapt to wide input voltage ranges while maintaining EMC compliance.
2Reliability
If additional components (EMI filter, boost converter, transient limiter) are added to handle voltage transients and EMI, then EMC compliance and voltage range handling improve, but the converter efficiency decreases due to additional losses
Solution Approach 1:
The integrated module employs dynamic control that switches between different operating modes based on real-time input voltage conditions. During steady-state operation, the module operates in passive EMI filter mode with minimal energy loss. During voltage transients or low-input conditions, it dynamically activates boost or transient limiting functions. This dynamic operation ensures EMC compliance while minimizing energy losses by activating additional functions only when necessary.
Solution Approach 2:
The control circuit monitors input voltage parameters and dynamically adjusts the operating mode of the integrated module. When input voltage is within the steady-state range, the module maintains high efficiency by operating as a passive filter. When voltage deviations occur, the control parameters change to activate active regulation functions, thereby maintaining reliability while optimizing efficiency across different operating conditions.
3Productivity
If passive EMI filter components are used during steady-state operation, then the circuit maintains simple operation and good efficiency, but it cannot actively regulate voltage during transients
Solution Approach 1:
The integrated module transitions dynamically between passive and active operating modes. During steady-state operation, it functions as a simple passive EMI filter, maintaining high efficiency and low complexity. When voltage transients or deviations occur, the control circuit dynamically activates the active regulation functions (boost converter or transient limiter), enabling the same hardware to adapt to varying voltage conditions while preserving efficiency during normal operation.
Solution Approach 2:
The control circuit periodically monitors input voltage conditions and switches between operating modes as needed. During normal steady-state conditions, the module operates in passive filter mode. Upon detecting voltage deviations, it periodically activates active regulation functions to correct the voltage, then returns to passive mode once stability is restored. This periodic switching maintains efficiency while providing voltage regulation capability when required.
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
This solution enables DC/DC converters to efficiently handle wide input voltage ranges without the need for separate modules, reducing volume and cost while maintaining EMC compliance and optimizing efficiency and density.
Implementation Method 1
when a common mode noise current passes through the common mode EMI inductor LCM, the common mode noise current magnetizes the core of the common mode EMI inductor LCM
Implementation Method 2
The differential mode EMI choke or inductor LDM1 suppresses differential mode noise generated by the power converter 112
Implementation Method 3
The common mode bypass capacitors CY1 and CY2 conduct common mode noise generated by the power converter 112 to ground
Data Source
AI summary
This disclosure describes systems, methods and articles of a passive EMI filter integrated with an active boost converter for low-side line transients and/or an active clipper for high-side line transients. During steady-state operation, the active circuitry is disabled so the circuit functions as a passive EMI filter. Inductive and capacitive components used in the passive EMI filter during steady-state operation may serve a dual role and become part of a boost converter when input voltage is below a low-line steady-state and, in some variations, the inductive and capacitive components may become part of a transient clipper when the input voltage is above a high-line steady-state level. The transient clipper may be implemented as a linear pass element or as a switch-mode converter (e.g., buck converter).