The white paper of InfraTec is intended to show how to turn on the digital detector with a basic microcontroller board like the Arduino Uno. You will also learn how to configure the detector and retrieve data.
Digital detectors PyrIQ convert the analog signal, which can be filtered and amplified in several stages, directly into a digital signal with 16-bit resolution. All signal processing is performed by an ASIC (Application-Specific Integrated Circuit), in which the analog front end acts as a conventional transimpedance amplifier. Thus, users receive a digital measurement signal that can be read out via an I²C interface and immediately processed.
For high precision measurement, especially in gas analysis, synchronization of the transmitter and detector clock is necessary. For digital pyroelectric detectors, a clock input (pin) is available for this purpose, which is used to specify the exact system clock or sample time. This makes it possible to generate a time signal with a very precise sampling frequency. Another special feature compared to the analog technology of our digital detector is the “fast recovery after saturation”. This function detects an overload due to a faulty operating condition – for example, due to extreme temperature fluctuations or mechanical influences – and automatically resets the analog front end.
Digital Pyroelectric Detectors – What are the Benefits?
Simple integration
The built-in ASIC, which already contains an A/D converter, eliminates complex signal processing steps and the detector can be connected directly to the microcontroller without adjustments. This allows quick and easy system integration. The user is provided with digital measured values with a sampling frequency of up to 1 kHz, which can be read out and processed directly without additional hardware components via the I²C interface.
Improved electromagnetic compatibility
The entire signal conversion of the detector is spatially concentrated and shielded, resulting in higher electromagnetic compatibility (EMC). The detector is more resistant to electromagnetic interference, so EMC measurements can be reduced by the user.
Processing of variable signals
The most important characteristics to characterize the performance of a pyroelectric detector are the frequency-dependent sensitivity, the noise density and the detectivity D*. Depending on the measuring system (measuring setup) and the principle, there are different requirements for well-dimensioned signal processing. The digital detector offers complete flexibility in configuring the detector parameters, during development and also during subsequent use. The sensitivity of the digital detector can be flexibly adjusted depending on the radiated power falling on the detector, in order to optimally utilize the next input voltage range of the A/D converter. The Rf feedback resistance and the Cf feedback capacitance can be set individually for each spectral channel of the detector. This allows the user to optimally match sensitivity and stability performance to application requirements.