STS21

Datasheet STS21 Temperature Sensor IC Fully calibrated Digital output, I2C interface Low power consumption Excellent long term stability DFN type package – reflow solderable      Product Summary STS21, the new temperature sensor of Sensirion is about to set new standards in terms of size and intelligence: Embedded in a reflow solderable Dual Flat No leads (DFN) package of 3 x 3mm foot print and 1.1mm height it provides calibrated, linearized signals in digital, I2C format. Using the same CMOSens® technology as Sensirion‟s successful and industry proven SHT2x humidity and temperature sensors, the STS21 offers superior performance and reliability. The ±0.2°C temperature specification allows for implementation of the STS21 in applications with high demands on temperature accuracy. Dimensions Every sensor is individually calibrated and tested. Lot identification is printed on the sensor and an electronic identification code is stored on the chip – which can be read out by command. Furthermore, the resolution of STS21 can be changed by command (11bit up to 14bit), low battery can be detected and a checksum helps to improve communication reliability. With made improvements and the miniaturization of the sensor the performance-to-price ratio has been improved – and eventually, any device should benefit from the cutting edge energy saving operation mode. Sensor Chip 3.0 STS21 features a generation 4C CMOSens® chip. Besides the band gap temperature sensor, the chip contains an amplifier, A/D converter, OTP memory and a digital processing unit. 2.0 typ 1.4 typ 3.0 STS21 D0AC4 0.3 typ 0.8 typ Material Contents 1.1 2.2 0.2 0.3 NC VDD SCL 0.75 0.4 Bottom View While the sensor itself is made of Silicon the sensors‟ housing consists of a plated Cu lead-frame and green epoxy-based mold compound. The device is fully RoHS and WEEE compliant, e.g. free of Pb, Cd and Hg. 0.4 Additional Information and Evaluation Kits 1.5 2.4 1.0 1.0 NC VSS SDA Figure 1 Drawing of STS21 sensor package, dimensions are given in mm (1mm = 0.039inch), tolerances are ±0.1mm. The die pad (center pad) is internally connected to VSS. The NC 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 Additional information such as Application Notes is available from the web page www.sensirion.com. For more information please contact Sensirion via info@sensirion.com. For STS21 two Evaluation Kits are available: EK-H4, a four-channel device with Viewer Software, that also serves for data-logging, and a simple EK-H5 directly connecting one sensor via USB port to a computer. Version 2 – December 2011 1/12 Sensor Performance Temperature Specification Parameter Condition 14 bit 12 bit Resolution1 Electrical Specification min typ Accuracy tolerance2 max typ 0.01 0.04 Response extended Time3 Units °C °C 0.2 see Figure 2 °C 0.1 °C Repeatability Operating Range max °C -40 125 °C 5 30 s 63% Long Term Drift < 0.04 T (°C) ± 2.0 °C/yr maximal tolerance typ max Units 3.0 3.6 V sleep mode 0.15 0.4 µA Supply Current, IDD4 measuring 200 300 330 µA sleep mode 0.5 1.2 µW Power Dissipation4 measuring 0.6 0.9 1.0 mW average 11bit 8.6 µW 2 Communication digital 2-wire interface, I C protocol Table 1 Electrical specification. For absolute maximum values see Section 4.1 of Users Guide. Packaging Information Sensor Type typical tolerance ± 1.5 Parameter Conditions min Supply Voltage, VDD 2.1 STS21 ± 1.0 Packaging Tape & Reel Tape & Reel Tape & Reel Quantity 400 1500 5000 Order Number 1-100811-01 1-100812-01 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 1 Default measurement resolution is 14bit. It can be reduced to 13bit, 12bit or 11bit by command to user register. 2 Accuracies are tested at Outgoing Quality Control at 25°C and 3.0V. Values exclude long term drift. 3 Response time depends on heat conductivity of sensor substrate. www.sensirion.com This datasheet is subject to change and may be amended without prior notice. 4 Min and max values of Supply Current and Power Dissipation are based on fixed VDD = 3.0V and T