Single-Die PWM Gate Driver Isolation for Noise Coupling Control
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Solution Overview
Problem
Noise coupling between noise generating and noise sensitive circuits in a system-on-a-chip integration leads to poor performance in noise sensitive circuits due to voltage and current induced noise couplings, which are difficult to eliminate without increasing pin counts or compromising signal integrity.
Innovation Solution
An integrated noise isolation circuit with a floating structure and high voltage level shifters is implemented on a single silicon substrate, isolating noise sensitive circuits from noise generating circuits by terminating noise currents and avoiding capacitive coupling, allowing for noise immune signal transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If noise sensitive circuits and noise generating circuits are integrated on a single silicon die, then device integration and productivity are improved, but noise coupling between circuits increases causing performance degradation
Solution Approach 1:
The patent divides the silicon die into multiple isolated substrates, each containing either noise-sensitive circuits or noise-generating circuits. This physical segmentation prevents noise coupling while maintaining integration benefits, as each substrate operates independently with its own signal processing path.
Solution Approach 2:
The patent introduces an intermediary substrate that receives signals from noise-sensitive circuits and transmits them to noise-generating circuits. This intermediate layer acts as a buffer, isolating the two circuit types while enabling signal transfer, thus preventing direct noise coupling.
2Reliability
If separate power supply lines are used to avoid noise injection, then noise immunity is improved, but device complexity and pin count increase
Solution Approach 1:
By segmenting the device into separate substrates for noise-sensitive and noise-generating circuits, the patent eliminates the need for separate power supply lines. Each substrate can share common power supplies without causing noise injection, as the physical isolation prevents noise coupling through shared power rails.
3Adaptability or versatility
If floating well structure is used for high-side driver, then gate drive functionality is improved, but dV/dt induced noise injection to substrate increases
Solution Approach 1:
The patent extracts the floating well structure from the main substrate by placing it on a separate substrate. This removes the source of dV/dt induced noise from proximity to noise-sensitive circuits, eliminating the harmful noise injection while preserving the high-side driver functionality on its own isolated substrate.
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 effectively minimizes noise coupling, enhancing the performance of noise sensitive circuits with improved common mode noise rejection and accurate dead-time insertion, while maintaining efficient signal routing and reducing the impact of noise on substrate nodes.
Implementation Method 1
Two kinds of noise couplings are present inside the gate driver IC, they are voltage induced capacitive coupling, and current and common stray impedance induced voltage coupling.
Implementation Method 2
An integrated noise isolation circuit is provided on a single silicon substrate die having a structural arrangement that minimizes noise... at least one floating structure for isolating influence of the noise
Data Source
AI summary
An integrated noise isolation circuit on a single silicon substrate die having a structural arrangement that minimizes noise. The integrated circuit including a noise sensitive circuit including an input stage; a noise generating circuit including an output stage; at least one high voltage level shift circuit coupling the noise generating and noise sensitive circuits for transferring a signal from the input to the output stage; and at least one floating structure for isolating influence of the noise.