MEMS Driver Circuit for High-Voltage Startup Oscillation Control
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Solution Overview
Problem
Existing MEMS drivers for devices like gyroscopes face challenges in providing efficient and cost-effective high voltage driving solutions that minimize power consumption and optimize oscillation control, particularly in startup phases, while maintaining accurate motion detection.
Innovation Solution
A MEMS driver design that includes a high voltage amplifier with programmable gain blocks and feedback paths, capable of switching between closed-loop and open-loop operation, using a voltage multiplier to generate high voltage without external storage, and featuring a simplified high-voltage amplifier structure with reduced power consumption and silicon area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a high voltage amplifier with external storage components is used, then high voltage driving capability is achieved, but device complexity and cost increase
Solution Approach 1:
The patent removes external high voltage storage components from the system, integrating only essential high voltage generation elements within the amplifier itself. This extraction of non-essential components reduces device complexity while maintaining high voltage driving capability through efficient internal voltage multiplication and amplification circuits.
Solution Approach 2:
The patent combines multiple functions (voltage multiplication, amplification, and control) into a single integrated high voltage amplifier unit. By merging these previously separate components into one cohesive device, the system achieves high voltage driving capability without requiring external storage components, thereby reducing overall device complexity.
2Measurement precision
If a complex feedback control system is implemented, then oscillation control precision is improved, but power consumption increases
Solution Approach 1:
The patent implements a simplified feedback control mechanism that applies control only when necessary, rather than continuous complex control. This partial action approach maintains sufficient oscillation control precision while significantly reducing power consumption by avoiding excessive control operations during stable operation phases.
Solution Approach 2:
The high voltage amplifier incorporates self-regulating characteristics where the system automatically adjusts its operation based on inherent feedback from the MEMS device response. This self-service capability maintains control precision without requiring complex external control circuits, thereby reducing overall power consumption.
3Loss of time
If startup oscillation is accelerated, then rise time is reduced, but detection error fluctuation increases
Solution Approach 1:
The patent applies a preliminary bias voltage to the MEMS proof mass before正式启动 oscillation. This preliminary action prepares the system for faster startup by pre-positioning the proof mass and reducing initial transient effects, thereby achieving faster rise time without causing excessive detection error fluctuation during the transition to steady-state oscillation.
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 efficient, low-power, and cost-effective operation of MEMS sensors by providing controlled oscillations and accurate motion detection, with reduced power consumption and simplified design, while eliminating the need for external high voltage storage components.
Implementation Method 1
Some MEMS gyroscopes include a driver to oscillate a proof mass of the MEMS gyroscope to allow the gyroscope to sense rotation motion
Data Source
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AI summary
In an example, a driver for a micro-electro-mechanical-system (MEMS) device can include a first input configured to receive a first command signal including an oscillatory command signal, a second input configured to receive a second command signal including a bias command signal, and an amplifier configured to receive a high voltage supply, to provide, to the MEMS device, a closed-loop output signal responsive to both the first command signal and the second command signal in a first state, and to provide an open loop output signal configured to substantially span a voltage range of the high voltage supply in a second state.