Signal Shaping Circuit for Offset and Common-Mode Noise Filtering
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Solution Overview
Problem
Existing circuit structures, such as half-bridge driving circuits, face challenges in effectively eliminating offset noise and common mode noise due to manufacturing deviations, which can lead to system failures and reduced accuracy.
Innovation Solution
A signal shaping circuit with turn-on and turn-off signal shaping modules, including specific transistors, resistors, capacitors, and inverters, is designed to enhance noise filtering capabilities, combined with a gate driving circuit that includes a pulse generating circuit, level shift circuit, noise filter circuit, and output stage driving circuit to effectively eliminate offset and common mode noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional level shift circuits are used in half-bridge driving circuits, then circuit integration and reliability are improved, but offset noise and common mode noise are generated due to manufacturing deviations and parasitic capacitor effects
Solution Approach 1:
The patent introduces an intermediary signal shaping circuit between the high-voltage level shift circuit and the subsequent control circuit. This intermediary circuit processes the noisy signal by comparing it with a reference voltage and generating a cleaned output signal, thereby eliminating both offset noise and common mode noise while maintaining circuit integration and reliability.
Solution Approach 2:
The signal processing function is segmented into multiple stages: the high-voltage level shift circuit generates the initial signal, the signal shaping circuit processes it by comparing with reference voltage, and the subsequent control circuit receives the cleaned signal. This segmentation allows each stage to be optimized independently, with the signal shaping circuit specifically addressing the noise problem.
2Object-affected harmful factors
If pulse filter circuits are used to eliminate common mode noise, then noise filtering effect is improved, but offset noise cannot be identified and eliminated
Solution Approach 1:
Instead of trying to filter out noise directly from the signal, the patent inverts the approach by comparing the noisy signal with a clean reference voltage. The signal shaping circuit detects the difference between the signal and reference, effectively identifying and eliminating offset noise while the filtering action removes common mode noise, achieving comprehensive noise suppression.
Data Source
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AI summary
Disclosed are a signal shaping circuit and a corresponding gate drive circuit. An additional NMOS transistor is added to the signal shaping circuit, thereby improving the requirements for the amplitude of an input differential signal, with resistors and capacitors that are connected in parallel being arranged in the circuit, so that the amplitude of the input differential signal needs to exceed a certain value for a certain period of time before the input differential signal is recognized as a trigger signal, and some interference or detuning noise caused by device mismatch is effectively filtered out. The gate drive circuit using the signal shaping circuit further comprises a pulse generating circuit, a level shifting circuit, a noise filter circuit and an output stage drive circuit. The cooperation of the circuits can effectively filter out the detuning noise and common mode noise. The use of the signal shaping circuit and the corresponding gate drive circuit can enable the circuits to work more reliably and to have a more stable performance.