An LMS Programming Scheme and Floating-Gate Technology Enabled Trimmer-Less and Low Voltage Flame Detection Sensor

Area of Science:

• Electronics
• Sensor Technology
• Semiconductor Devices

Background:

• Commercial flame detectors often require high voltage AC sources and mechanical trimmings for accurate flame detection.
• Existing flame detection systems are primarily used in absorption refrigerators and industrial gas heaters.

Purpose of the Study:

• To develop a trimmer-less flame detection sensor with high accuracy and a wide offset voltage adjustment range.
• To implement a Least Mean Square (LMS) programming scheme for precise offset voltage control in operational amplifiers.

Main Methods:

• Utilized floating-gate transistors to construct two operational amplifiers.
• Employed an LMS programming scheme with electron injection to set the offset voltage of the amplifiers.
• Designed a flame detection sensor integrating a voltage follower and a voltage comparator, both with programmable offset voltages.

Main Results:

• Achieved a 0.95 V_RMS trimmer-less flame detection sensor.
• Demonstrated accurate flame presence measurement after a maximum of 35 LMS-algorithm iterations.
• The sensor operates based on detecting electrical changes from flame ionization.

Conclusions:

• The proposed LMS-programmed, floating-gate operational amplifier-based sensor offers a precise and trimmer-less solution for flame detection.
• This approach simplifies flame detection systems, potentially reducing complexity and cost compared to conventional methods.
• The sensor's ability to accurately measure flame presence with minimal iterations highlights its practical applicability.