EMI Modulation Circuit With Selectable Slew Rate Control
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Solution Overview
Problem
Conventional power management chips fail to effectively modulate the slew rate of the voltage supplied to the load, leading to prolonged EMI adjustment times and increased development time for power supply products.
Innovation Solution
An electromagnetic interference modulation circuit with a slew rate adjustment module that includes a multiplexing unit and electromagnetic interference modulation units, allowing for precise control of the slew rate of the voltage signal through a one-to-one mapping relationship, thereby improving EMI and reducing adjustment time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a simple closed-loop control is used to achieve a balance between response speed and system stability, then the control is simple to implement, but the slew rate of the voltage supplied to the load cannot be modulated
Solution Approach 1:
The control system is segmented into multiple independent modules: a selecting module that chooses from multiple slew rate control signals, a slew rate adjustment module that generates multiple electromagnetic interference modulation signals with different slew rates, and a power stage module that outputs voltage signals. This segmentation enables selective modulation of slew rate while maintaining overall system stability and simplicity.
2Reliability
If the slew rate modulation issue of the load voltage cannot be solved, then the power system can passively rectify the EMI issue, but the time for verifying and adjusting EMI issue is extended
Solution Approach 1:
The patent implements preliminary action by pre-generating multiple electromagnetic interference modulation signals with different slew rates in the slew rate adjustment module. The selecting module can directly choose from these pre-prepared signals based on EMI verification results, eliminating the need for time-consuming iterative adjustments and passive rectifications during the verification process.
3Measurement precision
If multiple electromagnetic interference modulation units are used with different conductive current values, then the slew rate can be precisely modulated, but the device complexity increases
Solution Approach 1:
The patent applies dynamics by making the circuit configuration adjustable rather than fixed. The selecting module dynamically chooses which electromagnetic interference modulation unit to activate based on the required slew rate, allowing the system to adapt its complexity level. Not all modulation units need to be active simultaneously, and the system can scale the number of units based on precision requirements.
Data Source
AI summary
An electromagnetic interference modulation circuit includes an instruction module, a slew rate adjustment module, and a power stage module. The instruction module outputs a selecting signal according to an instruction signal. The slew rate adjustment module connected to the instruction module is configured to generate a plurality of electromagnetic interference modulation signals, and output an electromagnetic interference modulation signal corresponding to the selecting signal. The power stage module connected to the slew rate adjustment module and an output end is configured to output a voltage signal to the output end according to the electromagnetic interference modulation signal.