TIDUEJ6A
January 2019 – July 2022
Description
Resources
Features
Applications
5
1
System Description
1.1
Key System Specifications
2
System Overview
2.1
Block Diagram
2.2
Design Considerations
2.2.1
Flow Measurement
2.2.2
ToF Measurement
2.2.2.1
ADC-Based Acquisition Process
2.2.2.2
Ultrasonic Sensing Flow-Metering Library
2.2.3
Low-Power Design
2.2.3.1
Energy-Efficient Software
2.2.3.2
Optimized Hardware Design
2.2.3.3
Efficient Use of FRAM
2.2.3.4
The LEA Advantage
2.3
Highlighted Products
2.3.1
MSP430FR6043
2.3.2
OPA836 and OPA838
2.3.3
TS5A9411
2.4
System Design Theory
2.4.1
Signal Processing for ToF
3
Hardware, Software, Testing Requirements, and Test Results
3.1
Required Hardware and Software
3.1.1
Hardware
3.1.1.1
EVM430-FR6043
3.1.2
Software
3.1.2.1
MSP Driver Library (MSP DriverLib)
3.1.2.2
Ultrasonic Sensing Flow Metering Library
3.1.2.3
Application
3.1.2.3.1
Application Customization
3.1.2.3.2
LCD Stand-Alone Mode
3.1.2.4
USS Design Center (PC GUI)
3.1.3
Transducer and Meter
3.1.3.1
Frequency Characterization of Transducer and Meter
3.2
Testing and Results
3.2.1
Test Setup
3.2.1.1
Connecting Hardware
3.2.1.2
Building and Loading Software
3.2.1.2.1
Using Code Composer Studio IDE
3.2.1.2.2
Using IAR Embedded Workbench IDE
3.2.1.3
Executing Application
3.2.1.4
Configure Device and Observe Results Using GUI
3.2.1.5
Customization and Optimization
3.2.2
Test Results
3.2.2.1
Single-Shot Standard Deviation
3.2.2.2
Zero-Flow Drift
3.2.2.3
Absolute Time of Flight Measurements
3.2.2.4
Variability in Zero Flow Drift Across Transducers
3.2.2.5
Flow Measurements
3.2.2.6
Average Current Consumption
3.2.2.7
Memory Footprint
4
Design and Documentation Support
4.1
Design Files
4.1.1
Schematics
4.1.2
Bill of Materials
4.1.3
PCB Layout Recommendations
4.1.3.1
Layout Prints
4.1.4
Altium Project
4.1.5
Gerber Files
4.1.6
Assembly Drawings
4.2
Software Files
4.3
Related Documentation
4.4
Terminology
4.5
Trademarks
4.6
Support Resources
5
About the Authors
6
Revision History
Features
Best-in-class metrology performance: ±250-ps zero-flow drift (ZFD) and 500-ps single-shot standard deviation across 200-kHz to 500-kHz transducers
Low power consumption: <20 µA across 200-kHz to 500-kHz transducers with one set of comprehensive results per second
Flexibility to operate with a variety of pipes and transducers
Easy to test and customize using ultrasonic sensing design center graphical user interface (GUI) and Ultrasonic sensing (USS) software library
±1% flow accuracy up to 12000 lph with dynamic range of 200:1
3-lph minimum detectable flow rate
Waveform capture based processing features:
Robust performance against variation of transducer characteristics over temperature
Ease of meter calibration, insensitive to transducer characteristic variations
Allows meter diagnostics like monitoring transducer aging and external noise interference
On-chip automatic gain control (AGC) allows dynamic implementation to handle changing transducer or gas environmental conditions