IR sensor modules provide robust operation in direct sunlight without attenuators

Vishay Intertechnology, Inc has released two new fixed-gain IR sensor modules to reduce costs and improve stability for outdoor sensor applications. Providing typical irradiance of 1.3mW/m² in compact Minimold packages, the surface-mount TSSP93038DF1PZA and leaded TSSP93038SS1ZA deliver robust operation in direct sunlight while still supplying enough sensitivity for light barrier applications.

Unlike high-sensitivity fixed-gain IR sensor modules that need attenuators such as dark panels, apertures, and sunshades to protect them against sunlight – adding to overall solutions costs – the controlled sensitivity of the devices enables them to operate in full sunlight without unwanted pulses. Also, for short-range presence and proximity applications, the sensors' decreased sensitivity removes the necessity for extremely low emitter forward currents, which can lead to unstable intensity outputs.

Featuring a fast 260μs reaction time, the devices deliver long-range proximity sensing (1m with TSAL6100 at 100mA). With the same setup, a range of 11m is possible in light curtain applications. Longer ranges can be accomplished by utilising a more focused emitter like the VSLY5940 or by increasing the emitter forward current.

The devices are excellent for sensing the distance to objects for toys, drones, robots, and vicinity switches; presence detection for traffic control lights and parking lot, gateway access, and water level sensors; and light barriers for sports racing and lawnmower robots. They may also be employed as reflective sensors for hand dryers, towel or soap dispensers, water faucets, toilets, vending machine fall detection, and security and pet gates.

The devices operate over a supply voltage range from 2V to 3.6V, feature a low supply current of 0.35mA, and are sensitive to a carrier frequency of 38kHz. Developed to receive IR pulses from an emitter with a peak wavelength of 940nm, the devices are insensitive to ripple noise on the supply voltage and provide shielding against EMI, while an IR filter suppresses visible light. The modules are RoHS-compliant, halogen-free, and Vishay Green.