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Overview

The STHS34PF80 is an infrared sensor that can be used to detect the presence of stationary and moving objects

as well as overtemperature conditions. It measures the object's IR radiation with unique TMOS technology to

detect its presence or motion when the object is inside the field of view.

An optical band-pass filter is deposited over the sensor limiting its operating range within the wavelengths of 5 µm

and 20 µm, making it insensitive to visible light and other bands.

The sensor is based on a matrix of floating vacuum thermal transistors MOS (TMOS) connected together and

acting as a single sensing element. A state-of-the-art thermal isolation is achieved thanks to ST's unique MEMS

manufacturing technologies, allowing the sensor to translate the smallest temperature changes into electrical

signals that, in turn, are fed to the ASIC.

The sensor is split into two parts, one exposed to IR radiation and the other one shielded. Differential reading

between the two parts is implemented to remove the effect of sensor self-heating.

The STHS34PF80 embeds a high-accuracy temperature sensor to measure the ambient temperature and

compensate for heating of the device / application.

The ASIC also implements dedicated smart processing to detect / discriminate between stationary and moving

objects and which can assert dedicated interrupts.

Different ODRs from 0.25 Hz to 30 Hz and a one-shot mode are available.

The STHS34PF80 is equipped with an I²C / 3-wire SPI interface and is housed in an OLGA 3.2 x 4.2 x 1.455 mm

10L package compatible with SMD mounting.

The field of view guaranteed by the package is 80°.

Figure 1. Block diagram

TMOS

Sensor

TMOS Analog

Front

End

ADC1

Temperature

Sensor

ADC2

Digital

Logic

(Registers / LPF

etc..)

I2C

SPI

Digital Interface

Interrupt

Power

management

Clock generator

Voltage &

Current bias

Calibration

registers

CS

SCL/SPC

SDA/SDI/O

INT

STHS34PF80

Overview

DB4312 - Rev 1

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