CMOS Sensors with Direct Digital and Analog Interfaces

Sensirion sensor products ensure excellent performance and correspondingly great customer utility. They are all based on the company’s advanced CMOSens^® Technology, which enables the sensor component to be integrated with the digital and analog signal processing circuitry on a miniature CMOS silicon chip.

This is applied in advanced semiconductor technology, using specific microsystem processing steps to create the microsensor structures on specially created and patented semiconductor parts. The resulting sensor chips enable precise and reliable sensing of the preferred physical parameters, such as relative humidity, mass flow, or temperature. CMOSens^® therefore symbolizes a guarantee of reliability, high precision, and functionality integrated with cost effectiveness.

Precision and Reliability

Integrating the sensor with the signal processing circuitry guarantees that the weak analog sensor signals can be amplified and digitized with high precision directly where they are produced, thus making them resistant to interference.

This provides the base for the exceptionally high measurement accuracy of CMOSens^® sensors. With the elimination of fault-prone solder joints, users also gain from excellent long-term stability, as has been confirmed by wide-ranging field tests. Additionally, CMOSens^® Technology is based on established and reliable regular processes used in semiconductor fabrication, which also add to the high reliability and reproducibility of Sensirion sensor solutions.

Functionality

CMOSens^® chips are smart microsensor systems with a high degree of functionality and integration. This is offered by digital and analog signal processing, which is combined into the semiconductor chip together with the sensor component.

Sensirion chips are further optimized by extra intelligence for low-power operation, self-tests, and built-in linearization, digitization and temperature compensation (the latter using an integrated temperature sensor). The current high level of functionality and intelligence results from many years of development efforts, as can be observed from the evolutionary stages leading up to the current chip generation:

1^st generation: miniaturized sensor component

2^nd generation: 1^st generation plus A/D converter and amplifier

3^rd generation: 2^nd generation plus intelligence for linearization and temperature compensation

4^th generation: 3^rd generation plus memory to store calibration data

Cost Effectiveness

As a basic semiconductor fabrication process, CMOS is enhanced for reliable mass production. Sensors fabricated in CMOSens^® Technology are based on this cost-enhanced standard process, which assures customers of a best price/performance ratio.

Integrating the sensor components with the signal processing circuitry on a single small chip allows system costs and package sizes to be decreased even further compared with conventional sensors. Consequently, users gain very high reliability and quality at a lower price.

Testing and Calibration

A key technical advantage for customers of Sensirion products is that the company’s digital sensor systems are completely calibrated. This means that expensive and cumbersome calibration procedures no longer have to be done by the customer.

Sensirion’s in-house sensor calibration and testing infrastructure allows effective testing and calibration procedures based on proven quality standards. The results are high quality, completely interchangeable multi sensor modules at unmatched price-performance ratios.

Overview

CMOSens^® with Humidity Sensors

Besides the resistive technique, the capacitive measurement principle, above all, established and proved itself as a standard in the past. For this principle, the sensor element is designed out of a capacitor.

CMOSens^® Technology for Gas Flow

The CMOSens^® sensor offers error-free gas flow metering that stays stable across long periods of time and creates a very quick, high-precision sensor signal.

CMOSens^® in Liquid Flow Measurement

For over three decades, thermal mass flow measurements using coils around a steel capillary have been the established concept in the precise measurement and dosing of mass flow rates.

This information has been sourced, reviewed and adapted from materials provided by Sensirion Inc.

For more information on this source, please visit Sensirion Inc.