ST infrared sensor (STHS34PF80) has the function of detecting human body and motion. Without Fresnel lens, it has a sensing angle of 80 degrees and a detection distance of 4 meters.

In the projector market, because the light source of the projector emits strong light exceeding 2000 lumens, the ST infrared sensor can be used with the projector to set the safety zone range to sense whether there is a person or object approaching. This can make people approach the safety zone range, and the projector light source will be actively reduced to avoid the projector light source irradiating the human eye.

However, the safety zone range that the projector needs to detect is different, and it can also be matched with Fresnel lens, which can reduce the sensing angle range of the infrared sensor to 10 degrees to 120 degrees and extend the sensing distance to 16 meters to 4 meters.

Application scenario diagram

Display board photo

Scheme diagram

Lens TMOS63-10 for TMOS EVK

Core technology advantages

1.STHS34PF80 is an infrared sensor that can be used to detect the presence and over-temperature conditions of stationary and moving objects. It uses unique TMOS technology to measure the infrared radiation of an object and detect its presence or movement when the object is in the field of view.

2.An optical bandpass filter is deposited on the sensor, limiting its operating range to 5 µm to 20 µm wavelengths, making it insensitive to visible light and other bands.

3.This sensor is based on a floating vacuum thermal transistor MOS (TMOS) matrix connected together as a single sensing element. ST's unique MEMS implements the most advanced thermal isolation manufacturing technology, allowing the sensor to convert the smallest temperature changes into electrical change signals that are sent to the ASIC.

4.The sensor is divided into two parts, one part is exposed to infrared radiation and the other part is shielded. The connection between the two parts is to eliminate the effect of sensor self-heating.

5.STHS34PF80 embeds a high-precision temperature sensor to measure ambient temperature and can measure the precise infrared radiation of an object. The ASIC also implements dedicated intelligent processing to detect/distinguish between stationary and moving objects and can declare dedicated interrupts.

6. Provides different ODRs from 0.25 Hz to 30 Hz and one-shot mode.

7.STHS34PF80 is equipped with I²C/3-wire SPI interface and adopts OLGA 3.2 x 4.2 x 1.455 mm package 10L package compatible SMD installation.

8. The package guarantees a field of view of 80°.

Solution Specifications

• High-sensitivity infrared presence and motion detection sensor

• Up to 4 meters without lens for objects 70 x 25 cm² in size

• Integrated silicon IR filter

• Ability to detect stationary objects

• Ability to distinguish between stationary and moving objects

• 80° field of view

• Embedded smart algorithm for presence/motion detection

• Supply voltage: 1.7V to 3.6V

• Supply current: 10 µA

• 2-wire I²C / 3-wire SPI serial interface

• Programmable ODR from 0.25 Hz to 30 Hz

• One-shot mode