19 May 2022

Digital pyroelectric detectors ideal for mobile devices

The digital compensated 2-channel detector in the TO39 housing: LID-2322

Infratec has announced a new range of digital pyroelectric detectors, alongside the 4-channel detector, the company has also developed the LID-2322: a compensated 2-channel detector in the TO39 housing which is primarily intended for gas analysis devices. Analogue pyroelectric detectors from Infratec have been used in a number of different customer applications for over 30 years.

The two-channel LID-2322 is said to be ideal for mobile devices thanks to its small and compact housing and it can also run on batteries. It is suitable for use in harsh environments, as the optional thermal compensation reduces the effect of external fluctuations. The integrated I²C communication interface with up to 1 MHz (fast mode plus – FM+) enables the measured values to be read out immediately via a PC or microcontroller in a reliable, standardised manner. Apart from the power supply connections, only two additional connections are required for operation of the detector to allow it to be parameterised and read out. This keeps the external hardware requirements to a minimum and makes it much easier to integrate the detector into the application. Using the additional clock input makes it possible to synchronise the radiator and the detector clock, allowing highly precise signal evaluation with a stable frequency.

The digital detector is based on lithium tantalate (LiTaO3) as sensor material. In contrast to other materials, LiTaO3 offers a good signal-to-noise ratio and high sensitivity without additional cooling or temperature stabilisation. All of the internal signal processing is carried out by an ASIC (application-specific integrated circuit). The signal generated by the pyroelectric elements is amplified in this circuit and then digitised with a 16-bit A/D converter. In contrast to analogue detectors, this allows the detector parameters to be flexibly configured in order to optimise the signal processing. The spatial concentration and shielding of the entire signal conversion and, in particular, the interference-prone analogue lines of the detector offer improved electromagnetic compatibility (EMC). Another special feature is the “fast recovery after saturation” function. This function detects the override due to a defective operating status or external override and automatically resets the analogue input stage within a few milliseconds. This significantly reduces the time it takes for a measuring system to be ready for use again after starting or after temperature changes.

Company info: Infratec