Time-Domain Multiplexed Signal Processing for Multiple MEMS Devices
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Solution Overview
Problem
Current MEMS systems with multiple inertial measurement devices require separate analog signal processing blocks for each device, leading to redundancy, increased size, cost, and complexity due to multiple occurrences of identical components.
Innovation Solution
Implementing a time-domain multiplexed architecture that shares a single signal processing block among multiple MEMS devices, with anti-aliasing filters placed after track-and-hold switches, allowing a single sense channel to serve multiple devices, including gyroscopes, by processing signals in a multiplexed manner.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate analog signal processing blocks are used for each MEMS device, then signal processing quality is maintained, but device complexity and area increase
Solution Approach 1:
The patent merges multiple separate signal processing blocks into a single shared analog signal processing block that serves multiple MEMS devices. The TIA, PGA, ZIF mixer, and rate amplifier are consolidated into one block that time-multiplexes signals from different MEMS devices, reducing component count and system complexity while maintaining processing quality through careful timing and filtering.
Solution Approach 2:
The patent implements periodic time-multiplexed switching where the shared signal processing block alternates between serving different MEMS devices in time slots. Track-and-hold switches periodically capture signals from different devices, and the anti-aliasing filter processes them sequentially, enabling one block to handle multiple devices through periodic time-sharing.
2Reliability
If separate analog signal processing blocks are used for each MEMS device, then signal integrity is preserved, but area and power consumption increase
Solution Approach 1:
The patent consolidates multiple signal processing functions (TIA, PGA, ZIF mixer, rate amplifier) into a single shared block, reducing the chip area required for signal processing components. The time-multiplexed architecture allows one physical block to serve multiple MEMS devices, directly reducing the stationary object area while maintaining signal integrity through proper timing and filtering.
3Reliability
If separate analog signal processing blocks are used for each MEMS device, then each device has dedicated processing, but manufacturing cost and complexity increase
Solution Approach 1:
The patent creates a universal signal processing block that can handle signals from multiple different MEMS devices through time-multiplexed operation. The same TIA, PGA, mixer, and amplifier circuitry serves multiple devices sequentially, making the processing block multi-functional rather than dedicated to a single device, thereby simplifying manufacturing and reducing fabrication complexity.
4Area of stationary object
If a shared signal processing block is used for multiple MEMS devices, then area and power are reduced, but signal processing complexity increases
Solution Approach 1:
The patent uses periodic time-multiplexed switching with track-and-hold circuits that capture signals from different MEMS devices in sequential time slots. The anti-aliasing filter processes these signals periodically, and the shared analog block operates in a time-shared manner, reducing area while managing complexity through structured periodic operation rather than simultaneous multi-channel processing.
Data Source
AI summary
A sense channel signal processing block is time-domain multiplexed among multiple MEMS devices and utilizes an anti-aliasing filter disposed after track-and-hold switches, to prevent the bandwidth of the sense channel from being limited by the anti-aliasing filter.