Pyroelectric Detectors - Current Mode

01 Mar 2016

The LASER COMPONENTS Pyro Group (LCPG) has experienced high demand for their in-house production of pyroelectric detectors, and a greater preference for current mode (CM) operation over voltage mode (VM). Most popular are lithium tantalite (LTO) dual channel pyros used in gas sensing by combining one active (chosen gas, e.g. CO₂) and one reference (to normalise signals) in a single TO-package.

CM operation provides a higher responsivity, over voltage mode, with a low offset with a low temperature dependence.An op-amp is used in conjunction with a negative feedback loop. CM operation also provides a low electrical time constant and faster recovery times allowing one to use CM devices at much higher frequencies than VM devices with less signal loss.

Typical current mode circuit

Dual channel pyros in a TO-39 housing offer up to two sensors with an active area of up to 3.0 x 3.0 mm². They are available both with and without an additional blind element, which permits temperature fluctuation compensation (TFC), as well as higher internal amplification. Wherever reasonably possible, integrated microphonic reduction is included within the detector. A wide range of narrow band pass optical filters makes it possible to configure a suitable detector for nearly any application.

CM pyrodetectors are particularly easy to integrate into systems. In fact it is almost identical to Plug&Play integration.

The following product lines are available: