Analog Switch Multiplexer Circuit for High-Voltage Gate Protection
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Solution Overview
Problem
Existing analog switch circuits face limitations in handling analog signals above 3.3 V, as they can be damaged by exceeding the gate breakdown voltage, requiring additional voltage regulation circuitry that increases complexity, especially in higher voltage applications.
Innovation Solution
The implementation of an analog switch multiplexer system using PMOS and NMOS transistors coupled with diodes and current sources, allowing the analog gate voltage to be transmitted up to the drain breakdown voltage, eliminating the need for voltage step-down circuitry by directing diodes inwardly and using digital control blocks to manage transistor states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If analog switch circuits are used to handle analog signals, then signal switching function is achieved, but the circuit cannot handle analog signals above 3.3V due to gate breakdown voltage limitation
Solution Approach 1:
The patent introduces an intermediary circuit configuration where diodes are directed inside the transistor structure to create a protected signal path. This intermediary structure allows high-voltage analog signals to be switched without directly exposing the gate to damaging voltage levels, as the diodes clamp the voltage before it reaches the gate.
Solution Approach 2:
The patent inverts the conventional diode orientation in analog switch circuits. Instead of directing diodes outwardly from the gate, the diodes are directed inside toward the gate, creating a voltage clamping effect that protects the gate from excessive voltage while allowing the drain-source path to handle higher voltages.
2Reliability
If voltage regulation circuitry is added to protect against excessive voltage, then transistor protection is achieved, but circuit complexity increases
Solution Approach 1:
The patent merges the voltage protection function directly into the transistor structure by integrating diodes within the switch circuit itself. This combination eliminates the need for separate external voltage regulation circuitry, as the protection mechanism is built into the fundamental switching structure.
Solution Approach 2:
The analog switch circuit provides its own voltage protection through the internally directed diodes that automatically clamp excessive voltages. The circuit serves its own protection needs without requiring external regulation components, making the design self-sufficient and simpler.
3Adaptability or versatility
If diodes are directed outside the transistor, then conventional circuit operation is maintained, but voltage protection is insufficient for high-voltage applications
Solution Approach 1:
The patent inverts the conventional diode orientation by directing diodes inside toward the gate rather than outside away from it. This inversion creates a voltage clamping effect that actively protects the gate from excessive voltage while maintaining proper switching operation, enabling the circuit to handle higher voltages safely.
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
Enables the switching of analog signals up to the drain breakdown voltage without damaging the transistors, simplifying circuit design and eliminating the need for voltage regulation in higher voltage applications, while ensuring safe operation by preventing excessive current flow.
Implementation Method 1
a first PMOS transistor coupled with a first diode, the first diode directed inside; a second PMOS transistor coupled with a second diode, the second PMOS transistor and the second diode coupled in series with the first PMOS transistor and the first diode, the second diode directed inside
Data Source
AI summary
A motor controller system that includes an analog switch multiplexer system is disclosed. Specific implementations include a plurality of field effect transistors (FETs) that may be configured to be operatively coupled with one or more phases of a motor. Each of the plurality of FETs may include a gate, an analog switch multiplexer coupled with each of the gates of the plurality of FETs and with an analog output, and a digital control block coupled with the analog switch multiplexer that may be configured to send a multiplexer select control signal to the analog switch multiplexer in response to receiving a serial peripheral interface signal.