3.0 0.2 0.4 Datasheet STS21 Temperature Sensor IC Fully calibrated 2 Digital output, I C interface Low power consumption Excellent long term stability DFN type package reflow solderable Product Summary Every sensor is individually calibrated and tested. Lot STS21, the new temperature sensor of Sensirion is about identification is printed on the sensor and an electronic to set new standards in terms of size and intelligence: identification code is stored on the chip which can be Embedded in a reflow solderable Dual Flat No leads read out by command. Furthermore, the resolution of (DFN) package of 3 x 3mm foot print and 1.1mm height it 2 STS21 can be changed by command (11bit up to 14bit), provides calibrated, linearized signals in digital, I C low battery can be detected and a checksum helps to format. improve communication reliability. Using the same CMOSens technology as Sensirions With made improvements and the miniaturization of the successful and industry proven SHT2x humidity and sensor the performance-to-price ratio has been improved temperature sensors, the STS21 offers superior and eventually, any device should benefit from the performance and reliability. The 0.2C temperature cutting edge energy saving operation mode. specification allows for implementation of the STS21 in applications with high demands on temperature accuracy. Dimensions Sensor Chip 3.0 STS21 features a generation 4C CMOSens chip. Besides the band gap temperature sensor, the chip 0.3 typ contains an amplifier, A/D converter, OTP memory and a digital processing unit. 0.8 typ Material Contents 1.1 2.2 While the sensor itself is made of Silicon the sensors housing consists of a plated Cu lead-frame and green Bottom View epoxy-based mold compound. The device is fully RoHS and WEEE compliant, e.g. free of Pb, Cd and Hg. 0.4 0.3 NC VDD SCL Additional Information and Evaluation Kits 2.4 Additional information such as Application Notes is available from the web page www.sensirion.com. For more information please contact Sensirion via 1.0 VSS SDA 1.0 NC info sensirion.com. For STS21 two Evaluation Kits are available: EK-H4, a Figure 1 Drawing of STS21 sensor package, dimensions are four-channel device with Viewer Software, that also serves given in mm (1mm = 0.039inch), tolerances are 0.1mm. The for data-logging, and a simple EK-H5 directly connecting die pad (center pad) is internally connected to VSS. The NC one sensor via USB port to a computer. pads must be left floating. VSS = GND, SDA = DATA. Numbering of E/O pads starts at lower right corner (indicated by notch in die pad) and goes clockwise (compare Table 2). www.sensirion.com Version 2 December 2011 1/12 0.75 2.0 typ 1.5 1.4 typ STS21 D0AC4 Sensor Performance Temperature Specification Electrical Specification Parameter Condition min typ max Units Parameter Conditions min typ max Units 14 bit 0.01 C Supply Voltage, VDD 2.1 3.0 3.6 V 1 Resolution sleep mode 12 bit 0.04 C 0.15 0.4 A 4 Supply Current, IDD measuring typ C 200 300 330 A 0.2 Accuracy 2 tolerance sleep mode max see Figure 2 C 0.5 1.2 W 4 Power Dissipation measuring 0.6 0.9 1.0 mW Repeatability 0.1 C average 11bit 8.6 W Operating Range extended -40 125 C 2 3 Communication digital 2-wire interface, I C protocol Response Time 63% 5 30 s Long Term Drift < 0.04 C/yr Table 1 Electrical specification. For absolute maximum values see Section 4.1 of Users Guide. T (C) 2.0 Packaging Information maximal tolerance Sensor Type Packaging Quantity Order Number typical tolerance 1.5 Tape & Reel 400 1-100811-01 STS21 Tape & Reel 1500 1-100812-01 1.0 Tape & Reel 5000 1-100832-01 0.5 0.0 -40 -20 0 20 40 60 80 100 120 Temperature (C) Figure 2 Typical and maximal tolerance for temperature sensor in C This datasheet is subject to change and may be amended without prior notice. 1 Default measurement resolution is 14bit. It can be reduced to 13bit, 12bit or 11bit by command to user register. 2 4 Accuracies are tested at Outgoing Quality Control at 25C and 3.0V. Values Min and max values of Supply Current and Power Dissipation are based on exclude long term drift. fixed VDD = 3.0V and T<60C. The average value is based on one 11bit 3 Response time depends on heat conductivity of sensor substrate. measurement per second. www.sensirion.com Version 2 December 2011 2/12