Infra-red sensor shuns sunlight outdoors

Author: EIS Release Date: Jul 24, 2023

Vishay has released an infra-red receiver designed to be used outdoors in light barriers and reflective presence detectors.

 

Vishay IR sensor TSSP93038 block

TSSP93038 will work up to 1m reflectively or 11m in a light curtain when irradiated at 1.3mW/m2.

 

The ambient light rejection strategy comes in two parts: the first is that the device’s peak sensitivity is to light at 940nm, and the second is that it includes an electronic band-pass filter centred on 38kHz.

 

 

Vishay IR sensor TSSP93038 app

 

It therefore needs to be used with a 940nm light source modulated at 38kHz (application left). The company’s TSAL6100 LED driven at 100mA will achieve the 1m and 11m ranges above, and its narrower-focussed VSLY5940 can be used at a greater distance.

 

 

 

The modulated LED signal can be further modulated by a lower frequency digital pulse stream if data transfer is needed.

 

“Unlike high-sensitivity fixed-gain IR sensor modules that require attenuators like dark panels, apertures, and sunshades to protect them against sunlight, the controlled sensitivity of the devices released today allows them to operate in full sunlight,” according to New Yorker Electronics, which is stocking the parts.

 

Power needs are 2 to 3.6V at 350μA.

 

It comes in two versions, both with the same 6.35mm (+leads) by 5.4mm package body, which is 5mm high including moulded lens.

 

Vishay IR sensor TSSP93038 photoTSSP93038DF1PZA has its three leads formed for surface-mounting (right), while TSSP93038SS1ZA is for through-hole mounting.