SHT4x th 4 Generation, High-Accuracy, Ultra-Low-Power, 16-bit Relative Humidity and Temperature Sensor Features Relative humidity accuracy: up to 1.0 %RH Operating range: 0100 %RH, -40125 C Temperature accuracy: up to 0.1 C Fully functional in condensing environment Supply voltage: 1.08 V 3.6 V Variable power heater Average current: 0.4 A (at meas. rate 1 Hz) NIST traceability Idle current: 80 nA JEDEC JESD47 qualification I2C FM+, CRC checksum, multip. I2C addr. Mature technology from global market leader Patented on-package PTFE membrane 1 Removable protection cap General Description SHT4x is a digital sensor platform for measuring relative humidity and temperature at different accuracy classes. Its I2C interface provides several preconfigured I2C addresses and maintains an ultra-low power budget. The power-trimmed internal heater can be used at three heating levels thus enabling sensor operation in demanding environments. The four-pin dual-flat-no- leads package is suitable for surface mount technology (SMT) processing and comprises an optional on-package patented PTFE 1 membrane or a removable protection cap. Device Overview Functional Block Diagram Products Details SHT40-AD1B base RH&T accur., 0x44 I2C addr. SHT40-BD1B base RH&T accur., 0x45 I2C addr. add. patented on-package PTFE SHT40-AD1F membrane SHT40-AD1P add. removable protection cap SHT41-AD1B Intermed. RH&T accur., 0x44 I2C addr. SHT45-AD1B 1.0 %RH, 0.1C accur., 0x44 I2C addr. Full product list on page 16 www.sensirion.com / D1 Version 3 April 2022 1/18 Contents 1 Quick Start Hello World ..................................................................................................................................... 3 2 Humidity and Temperature Sensor Specifications ....................................................................................... 4 2.1 Relative Humidity ............................................................................................................................................ 4 2.2 Temperature ..................................................................................................................................................... 6 2.3 Recommended Operating Conditions ...................................................................................................... 7 3 Electrical Specifications ........................................................................................................................................ 8 3.1 Electrical Characteristics .............................................................................................................................. 8 3.2 Timings ............................................................................................................................................................... 9 3.3 Absolute Maximum Ratings ......................................................................................................................... 9 4 Sensor Operation .................................................................................................................................................. 10 4.1 I2C communication ....................................................................................................................................... 10 4.2 I2C Communication Timing ....................................................................................................................... 10 4.3 Data type & length ........................................................................................................................................ 10 4.4 Checksum Calculation ................................................................................................................................. 10 4.5 Command Overview .................................................................................................................................... 11 4.6 Conversion of Signal Output ..................................................................................................................... 11 4.7 Serial number ................................................................................................................................................. 12 4.8 Reset & Abort ................................................................................................................................................. 12 4.9 Heater Operation........................................................................................................................................... 12 5 Physical Specification .......................................................................................................................................... 13 5.1 Package Description .................................................................................................................................... 13 5.2 Package Outline ............................................................................................................................................ 13 5.3 Land Pattern ................................................................................................................................................... 13 5.4 Pin Assignment & Laser Marking ............................................................................................................. 14 5.5 Thermal Information ..................................................................................................................................... 15 6 Quality and Material Contents........................................................................................................................... 15 7 Tape and Reel Packaging .................................................................................................................................. 15 8 Product Name Nomenclature ............................................................................................................................ 16 9 Ordering Information ............................................................................................................................................ 16 10 Bibliography .......................................................................................................................................................... 17 11 Revision History .................................................................................................................................................. 17 www.sensirion.com / D1 Version 3 April 2022 2/18