PM2.5/PM10 Particle Sensor for Air Quality Monitoring

Air pollution is one major problem that every individual is at risk. The pollutant, that contributes to these increases as industrialization and technology upgrade. Particulate matter or “PM” is the term being given to such particles like smoke, dust, dirt, and soot, which can be found in the air. The particulate matters can be dangerous depending on concentration and sizes. The sizes which considered can cause health risk are PM10 and PM2.5, which among the said particulate matter, PM2.5 (approximately 1/30th the average width of a human hair) is the most harmful PM for the reason that it can penetrate and lodge deeply to the lungs. The PM2.5/PM10 particle sensor for air quality monitoring reference design is an analog-front-end design, which can measure the particle concentration and sizes in the air. The design uses INA132, a low power single supply differential amplifier consisting a precision op-amp with a precision resistor network. It comes also with OPA2320 and OPA320, which is a new family of low-voltage CMOS op-amp that features a linear input stage with zero-crossover distortions that delivers excellent common mode rejection ratio (CMRR) of typically 114dB over the full input range. Read more

10W Stereo Class D Amplifier

This reference design is a simple 10W stereo amplifier providing a class AB performance with class D efficiency. Its efficiency is more optimized when a 12Ω to 16Ω speakers are loaded. It has an efficiency of up to 88% with a low quiescent current which is 24mA. In addition, this device is short circuit and thermal load protected and its power consumption has been reduced to increase battery life.  Read more

6W Inductor Free Stereo BTL Class D Audio Amplifier Circuit Diagram

The circuit is a class-D 6W inductor free audio amplifier for BTL (bridged-Tied Load) stereo speaker at up to 6Ω to 8Ω per channel. The TPA3144D2 has an advance EMI suppression technology with spread spectrum control and 1SPW modulation scheme that enables the use of inexpensive ferrite bead filters at the outputs. The design is applicable in inductor free application with limited distance length of wire between the amplifier and speakers. Read more