SHT40A-AW1B

SHT4XA SENSIRION | Alldatasheet

Document overview

• Manufacturer or author: Provided By alldatasheet.com(free datasheet download site)
• PDF pages: 18

Technical content

Datasheet sections

• 1 Quick Start – Hello World
• 2 Humidity and Temperature Sensor Specifications
• 2.1 Relative Humidity
• 2.2 Temperature
• 2.3 Recommended Operating Conditions
• 3 Electrical Specifications
• 3.1 Electrical Characteristics
• 3.2 Timings
• 3.3 Absolute Maximum Ratings
• 4 Sensor Operation
• 4.1 I2C communication
• 4.2 I2C Communication Timing
• 4.3 I2C Data type & length
• 4.4 I2C Checksum Calculation
• 4.5 I2C Command Overview
• 4.6 I2C Conversion of Signal Output
• 4.7 I2C Serial number
• 4.8 I2C Heater Operation
• 4.9 Pulse-Width Modulation (PWM) interface
• 4.10 PWM Conversion of Signal Output
• 4.11 Reset
• 5 Physical Specification
• 5.1 Package Description
• 5.2 Package Outline – Standard Package
• 5.3 Package Outline – Package with Wettable Flanks
• 5.4 Land Pattern
• 5.5 Pin Assignment & Laser Marking
• 5.6 Thermal Information
• 6 Quality and Material Contents
• 7 Tape and Reel Packaging
• 8 Product Name Nomenclature
• 9 Ordering Information
• 10 Bibliography
• 11 Revision History

Features

• Relative humidity accuracy: up to ±2 %RH
• Temperature accuracy: up to ±0.3 °C
• Supply voltage: 2.3 V … 5.5 V
• I2C fast mode plus, CRC checksum
• Pulse-width modulation interface
• Designed for 85°C/85%RH reliability testing
• Operating range: 0…100 %RH, -40…125 °C
• Fully functional in condensing environment
• Variable power heater
• AEC Q100 qualification, high-reliability design
• Mature technology from global market leader
• Patented protection options General Description SHT4xA is a n automotive -grade digital sensor platform for measuring relative humidity and temperature with different accuracy gradings. It fulfills demanding reliability requirements for automotive applications, such as 85°C/85%RH accelerated life tests . The sensors can be interfaced via I2C or pulse-width modulation. An integrated heater allows for advanced on-board- diagnostics while the sensor element is designed for reliable operation in harsh conditions such as condensing environments . The four-pin dual -flat-no-leads package is suitable for surface mount technology (SMT) processing and can be ordered with a wettable flanks option. Device Overview Functional Block Diagram Full product list on page 17 Products Details SHT40A-AD1B base RH&T accur., 0x44 I2C addr. SHT40A-FD1B base RH&T accur., PWM interface SHT40A-AW1B base RH&T accur., 0x44 I2C addr., wettable flanks SHT41A-AD1B improved RH&T accur., 0x44 I2C addr. SHT41A-AW1B improved RH&T accur., 0x44 I2C addr., wettable flanks

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1 Quick Start – Hello World

A typical application circuit for SHT4xA is shown on the left-hand side of Figure 1. After reaching the minimal supply voltage and allowing for the maximal power-up time of 1 ms the sensor is ready for I2C communication. The quickest way to measure humidity and temperature is pseudo-coded on the right-hand side of Figure 1. Together with the conversion formulae given in equations ( 1 ), ( 2 ), and ( 3 ), the digital signals can be translated into relative humidity and temperature readings. Typical application circuit Pseudo code i2c_write(i2c_addr=0x44, tx_bytes=[0xFD]) wait_seconds(0.01) rx_bytes = i2c_read(i2c_addr=0x44, number_of_bytes=6) t_ticks = rx_bytes[0] * 256 + rx_bytes[1] checksum_t = rx_bytes[2] rh_ticks = rx_bytes[3] * 256 + rx_bytes[4] checksum_rh = rx_bytes[5] t_degC = -45 + 175 * t_ticks/65535 rh_pRH = -6 + 125 * rh_ticks/65535 if (rh_pRH > 100): rh_pRH = 100 if (rh_pRH < 0): rh_pRH = 0 Figure 1: Typical application circuit (left) and pseudo code (right) for easy starting with the I2C interface. For details on the signal cropping in the last four lines see section 4.6. Find code re sources and embedded drivers on: https://github.com/Sensirion/embedded- sht/releases CAD files can be downloaded from SnapEDA (“*” considered as wildcard):

• SHT4*A-*D*B

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2 Humidity and Temperature Sensor Specifications

Every SHT4xA is individually tested and calibrated and is identifiable by its unique serial number (see section 4.7 for details on the serial number) . For the calibration, Sensirion uses transfer standards, which are subject to a scheduled calibration procedure. The calibration of the reference, used for the calibration of the transfer standards, is NIST traceable through an ISO/IEC 17025 accredited laboratory.

2.1 Relative Humidity

Parameter Conditions Value Units SHT40A RH accuracy1 typ. 3 %RH max. see Figure 2 - SHT41A RH accuracy1 typ. 2 %RH max. See Figure 3 - Repeatability2 high 0.08 %RH medium 0.15 %RH low 0.21 %RH Resolution3 - 0.01 %RH Hysteresis At 25°C 0.8 %RH Specified range4 extended5 0 to 100 %RH Response time6 t63% 4 s Long-term drift7 typ. <0.20 %RH/y Table 1: General relative humidity sensor specifications. Figure 2: SHT40A typical and maximal relative humidity accuracy at 25 °C. Figure 3: SHT41A typical and maximal relative humidity accuracy at 25 °C. 1 For definition of typ. and max. accuracy, please refer to the document “Sensirion Humidity Sensor Specification Statement”. 2 The stated repeatability is 3 times the standard deviation (3σ) of multiple consecutive measurement values at constant conditions and is a measure for the noise on the physical sensor output. Different repeatability commands are listed in Table 7. 3 Resolution of A/D converter. 4 Specified range refers to the range for which the humidity or temperature sensor specification is guaranteed. 5 For details about recommended humidity and temperature operating range, please refer to section 2.3. 6 Time for achieving 63% of a humidity step function, measured at 25°C and 1 m/s airflow. Humidity response time in the application depends on the design-in of the sensor. 7 Typical value for operation in normal RH/T operating range. Max. value is < 0.5 %RH/y. Value may be higher in environments with vaporized solvents, out-gassing tapes, adhesives, packaging materials, etc. For more details please refer to (Sensirion, Handling Instructions for Humidity Sensors, 2020). 0 10 20 30 40 50 60 70 80 90 100 Relative Humidity (%RH) SHT40A typ SHT40A max DRH (%RH) 0 10 20 30 40 50 60 70 80 90 100 Relative Humidity (%RH) SHT41A typ SHT41A max DRH (%RH)

www.sensirion.com / D1 Version 2 – July 2022 5/18 Relative Humidity Accuracy at the Extended Temperature Range The typical RH accuracy tolerances in the range of T=0°C … 80 °C are given in Figure 6 and Figure 7. RH (%RH) SHT40A |typ. Delta %RH| 100 4.5 0 4.5 0 10 20 30 40 50 60 70 80 Temperature [°C] RH (%RH) SHT41A |typ. Delta %RH| 100 0 10 20 30 40 50 60 70 80 Temperature [°C] Figure 4: Typical RH accuracy tolerance over humidity and temperature for SHT40A. Figure 5: Typical RH accuracy tolerance over humidity and temperature for SHT41A.

2.2 Temperature

Parameter Conditions Value Units SHT40A T Accuracy1 typ. 0.3 °C max. see Figure 6 - SHT41A T Accuracy1 typ. 0.3 °C max. See Figure 7 - Repeatability2 high 0.04 °C medium 0.07 °C low 0.1 °C Resolution3 - 0.01 °C Specified range4 - –40 to +125 °C Response time8 t63% 2 s Long-term drift9 typ. <0.03 °C/y Table 2: General temperature sensor specifications. 8 Temperature response time depends on heat conductivity of sensor substrate and design-in of sensor in application. 9 Max. value is < 0.04°C/y.

www.sensirion.com / D1 Version 2 – July 2022 6/18 Figure 6: SHT40A typical and maximal temperature accuracy. Figure 7: SHT41A typical and maximal temperature accuracy.

2.3 Recommended Operating Conditions

The sensor shows best performance when operated within the recommended normal temperature and humidity range of 5 °C … 60 °C and 20 %RH … 80 %RH, respectively. Long term exposure to conditions outside recommended normal range, especially at high relative humidity, may temporarily offset the RH signal ( e.g., +3 %RH after 60 h at > 80 %RH). After returning into the recommended temperature and humidity range the sensor will recover to within specifications by itself. Prolonged exposure to extreme conditions may accelerate ageing. To ensure stable operation of the hum idity sensor, the conditions described in the document (Sensirion, Handling Instructions for Humidity Sensors , 2020) regarding exposure to volatile organic compounds must be met. Please note as well that this does apply not only to transportation and manufacturing, but also to operation of the SHT4xA.

3 Electrical Specifications

Valid for all electrical specifications: Typical values correspond to VDD = 3.3 V and T = 25 °C. Min. and max. values are valid in the full temperature range -40 °C … 125 °C, at declared VDD levels and are based on characterization. ±0.0 ±0.2 ±0.4 ±0.6 ±0.8 ±1.0 -40 -20 0 20 40 60 80 100 120 Temperature (°C) SHT40A typ SHT40A max DT (°C) ±0.0 ±0.2 ±0.4 ±0.6 ±0.8 ±1.0 -40 -20 0 20 40 60 80 100 120 Temperature (°C) SHT41A typ SHT41A max DT (°C)

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3.1 Electrical Characteristics

Conditions Min Typ. Max Unit Comments Supply voltage VDD I2C 2.3 3.3 5.5 V - PWM 3.0 3.3 5.5 V - Power-up/down level VPOR Static power supply 0.7 - 2.3 V - Supply current (no heater) IDD I2C, Idle state - 18 - µA - I2C, PWM Measurement - 320 500 µA Average current consumption while sensor is measuring I2C: Aver., high repeatability Aver., med. repeatab. Aver., low repeatab. µA Aver. current consumpt. (contin. operation at 1Hz) PWM - 50 - µA Aver. current consumpt. (2Hz) Low level input voltage VIL I2C 0 - 0.3*VDD V - High level input voltage VIH I2C 0.7*VDD - VDD V - Pull up resistors Rp I2C, VDD < 3.0V 820 - - Ω - I2C, VDD ≥ 3.0V 390 - - Low level output voltage VOL I2C: VDD ≥ 2.3V, Rp ≥ 820 Ω - - 0.4 V - I2C: VDD ≥ 3.0V, Rp ≥ 390 Ω PWM: Rload > 100 kΩ 0 - 10%VDD V - High level output voltage VOH PWM: Rload > 100 kΩ 90% VDD - VDD V - Cap bus load Cb I2C: Rp ≥ 820 Ω: fast mode - - 400 pF Capac. bus load can be determined from Cb < trise /(0.8473*Rp). Rise times are trise = 300 ns for fast mode and trise = 120 ns for fast mode plus I2C: Rp ≥ 390 Ω, VDD ≥ 3.0 V: fast mode plus - - 340 pF PWM 0 - 1 nF - PWM frequency 1/tF PWM 95 122 150 Hz Base frequency Measurement frequency - PWM - 2 - Hz Frequency with which the sensor acquires new values Table 3: Electrical specifications.

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3.2 Timings

Parameter Symbol Conditions Min. Typ. Max. Units Comments I2C: Power-up time tPU After hard reset, VDD ≥ VPOR - 0.3 1 ms Time between VDD reaching VPOR and sensor entering idle state PWM: Power-up time tPU After hard reset, VDD ≥ VPOR - 5 10 ms Time between VDD reaching VPOR and sensor providing measurement data on output pins I2C: Soft reset time tSR After soft reset - - 1 ms Time between ACK of soft reset command and sensor entering idle state. Also valid for I2C general call reset. I2C: Measurement duration tMEAS,l Low repeatability - 1.3 1.6 ms The three repeatability modes differ with respect to measurement duration, noise level and energy consumption tMEAS,m Med. repeatability - 3.7 4.5 ms tMEAS,h High repeatability - 6.9 8.3 ms I2C: Heater-on duration tHeater Long pulse 0.81 1 1.19 s After that time the heater is automatically switched off Short pulse 0.08 0.1 0.12 s After that time the heater is automatically switched off Table 4 System timing specifications.

3.3 Absolute Maximum Ratings

Stress levels beyond those listed in Table 5 may cause permanent damage or affect the reliability of the device. These are stress ratings only and functional operation of the device at these conditions is not guaranteed. Ratings are only tested each at a time. Parameter Rating Supply voltage VDD -0.3 V … 6.0 V Max. voltage on any pin VSS - 0.3 V … VDD + 0.3 V Operating temperature range -40 °C … 125 °C Storage temperature range10 -40 °C …150 °C ESD HBM 4 kV ESD CDM 750 V Latch up, JESD78 Class II, 125°C +-100 mA Table 5: Absolute maximum ratings. 10 The recommended storage temperature range is 10-50°C. Please consult (Sensirion, Handling Instructions for Humidity Sensors, 2020) for more information.

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4 Sensor Operation

4.1 I2C communication

I2C communication is based on NXP’s I2C-bus specification and user manual UM10204, Rev.6, 4 April 2014. Supported I2C modes are standard, fast mode, and fast mode plus. Data is transferred in multiples of 16 -bit words and 8-bit check sum (cyclic redundancy check = CRC). All transfers must begin with a start condition (S) and terminate with a stop condition (P). To finish a read transfer, send not acknowledge (NACK) and stop condition (P). Addressing a specific slave device is done by sending its 7 -bit I2C address followed by an eight h bit, denoting the communication direction: “zero” indicates transmission to the slave, i.e. “write”, a “one” indicates a “read” request. Schematics of the I2C transfer types are sketched in Figure 8. Figure 8: I2C transfer types: First a write header is sent to the I2C slave, followed by a command, for example “measure RH&T with highest precision”. After the measurement is finished the read request directed to this I2C slave will be acknowledged and transmission of data will be started by the slave.

4.2 I2C Communication Timing

All details on the timing are following the interface specification of NXP’s user manual UM10204, Rev.6, 4 April 2014. Please follow mandatory capacitor and resistor requirements given in Table

4.3 I2C Data type & length

I2C bus operates with 8 -bit data packages. Information from the sensor to the master has a checksum after every second 8-bit data package. Humidity and temperature data will always be transmitted in the following way: The first value is the temperature signal (2 * 8-bit data + 8-bit CRC), the second is the humidity signal (2 * 8-bit data + 8-bit CRC).

4.4 I2C Checksum Calculation

For read transfers each 16-bit data is followed by a checksum with the following properties Property Value Name CRC-8 Message Length 16-bit Polynomial 0x31 (x8 + x5 + x4 +1) Initialization 0xFF Reflect Input/Output false/false Final XOR 0x00 Examples CRC(0xBEEF) = 0x92 Table 6 Data check sum properties. The master may abort a read transfer after the 16-bit data if it does not require a checksum.

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4.5 I2C Command Overview

(hex) Response length incl. CRC (bytes)

Description

[return values] 0xFD 6 measure T & RH with high precision (high repeatability) [2 * 8-bit T-data; 8-bit CRC; 2 * 8-bit RH-data; 8-bit CRC] 0xF6 6 measure T & RH with medium precision (medium repeatability) [2 * 8-bit T-data; 8-bit CRC; 2 * 8-bit RH-data; 8-bit CRC] 0xE0 6 measure T & RH with lowest precision (low repeatability) [2 * 8-bit T-data; 8-bit CRC; 2 * 8-bit RH-data; 8-bit CRC] 0x89 6 read serial number [2 * 8-bit data; 8-bit CRC; 2 * 8-bit data; 8-bit CRC] 0x94 - soft reset [ACK] 0x39 6 activate heater with 200mW for 1s, including a high precision measurement just before deactivation [2 * 8-bit T-data; 8-bit CRC; 2 * 8-bit RH-data; 8-bit CRC] 0x32 6 activate heater with 200mW for 0.1s including a high precision measurement just before deactivation [2 * 8-bit T-data; 8-bit CRC; 2 * 8-bit RH-data; 8-bit CRC] 0x2F 6 activate heater with 110mW for 1s including a high precision measurement just before deactivation [2 * 8-bit T-data; 8-bit CRC; 2 * 8-bit RH-data; 8-bit CRC] 0x24 6 activate heater with 110mW for 0.1s including a high precision measurement just before deactivation [2 * 8-bit T-data; 8-bit CRC; 2 * 8-bit RH-data; 8-bit CRC] 0x1E 6 activate heater with 20mW for 1s including a high precision measurement just before deactivation [2 * 8-bit T-data; 8-bit CRC; 2 * 8-bit RH-data; 8-bit CRC] 0x15 6 activate heater with 20mW for 0.1s including a high precision measurement just before deactivation [2 * 8-bit T-data; 8-bit CRC; 2 * 8-bit RH-data; 8-bit CRC] Table 7 Overview of I2C commands. If the sensor is not ready to process a command, e.g. because it is still measuring, it will return NACK to the I2C read header . Given heater power values are typical and valid for VDD=5V. At VDD=3.3V, heating power is reduced to 5% of the nominal value.

4.6 I2C Conversion of Signal Output

The digital sensor signals correspond to following humidity and temperature values: 𝑅𝐻 = (−6 + 125 ∙ 𝑆𝑅𝐻 216 − 1) %RH ( 1 ) 216 − 1) °C ( 2 ) 216 − 1) °F ( 3 ) N.B.: The RH conversion formula ( 1) allows values to be reported which are outside of the range of 0 %RH … 100 %RH. Relative humidity values which are smaller than 0 %RH and larger than 100 %RH are non-physical, however these “uncropped” values might be found beneficial in some cases (e.g. when the distribution of the sensors at the measurement boundaries are of interest) . For all users who don’t want to engage in evaluation of these non-physical values, cropping of the RH signal to the range of 0 %RH … 100 %RH is advised.

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4.7 I2C Serial number

Every single sensor has a unique serial number, that is assigned by Sensirion during production. It is stored in the one -time-programmable memory and cannot be manipulated after production. The serial number is accessible via I2C and is transmitted as two 16-bit words, each followed by an 8-bit CRC.

4.8 I2C Heater Operation

The sensor incorporates an integrated on-chip heater which can be switched on by the set of commands given in Table 7. There are three different heating powers and two different heating times accessible to the user. After reception of a heat er-on command, the sensor executes the following procedure: 1. The heater is enabled, and the timer starts its count-down. 2. On timer expiration a temperature and humidity measurement with the highest repeatability is started, the heater remains enabled. 3. After the measurement is finished the heater is turned off. 4. Temperature and humidity values are now available for readout. The maximum on-time of the heater commands is 1 second in order to prevent overheating of the sensor by unintended usage of the heater. Thus, there is no dedicated command to turn off the heater. For extended heating periods it is required to send periodic heater-on commands, keeping in mind that the heater is designed for a maximal duty cycle of less than 10%. To obtain a fast increase in temperature the idle time between consecutive heating pulses shall be kept minimal. Possible Heater Use Cases Please refer to the dedicated Sensirion application notes elaborating on various use cases of the heater. In general, the applications of the on-chip heater cover: 1. Removal of condensed / spray water on the sensor surface. Although condensed water is not a reliability / quality problem to the sensor, it will however make the sensor non- responsive to RH changes in the air as long as there is liquid water on the surface. 2. Drift-free operation in high humid environments. Periodic heating pulses allow for drift-free high-humidity measurements over extended periods of times. Important notes for operating the heater: 1. The heater is designed for a maximum duty cycle of 10%, meaning the total heater-on- time should not be longer than 10% of the sensor’s lifetime. 2. During operation of the heater, sensor specifications are not valid. 3. The temperature sensor can additionally be affected by the thermally induced mechanical stress, offsetting the temperature reading from the actual temperature. 4. The sensor’s temperature (base temperature + temperature increase from heater) must not exceed Tmax = 125 °C to have proper electrical functionality of the chip. 5. The heater draws a large amount of current once enabled (up to ~50mA in the highest power setting). Although a dedicated circuitry draws this current smoothly, the power supply must be strong enough to avoid large voltage drops that could provoke a sensor reset. 6. If higher heating temperatures are desired, consecutive heating commands can be sent to the sensor. To keep times between consecutive heating pulses minimal, polling of the sensor is advised. The heater shall only be operated in ambient temperatures below 65°C else it could drive the sensor outside of its maximal operating temperature.

4.9 Pulse-Width Modulation (PWM) interface

The sensor can be ordered with a pre-configured pulse width modulation (PWM) interface. This is a permanent interface configuration and cannot be changed by the user.

www.sensirion.com / D1 Version 2 – July 2022 12/18 After power-up of the sensor, it needs at most 10 ms until providing measurement data as PWM bit-stream on the respective output pins (see Figure 13). During that time the temperature and humidity pins have an undefined state. The PWM is based on a constant base frequency with period tF, as shown in Figure 9. The humidity and temperature signals are provided as duty cycle (tPW/tF) on that base frequency. A corresponds to RH = 119 %RH. Figure 9 PWM signal: The base frequency of 1/tF remains constant, whereas tPW is variable. The physical signal of temperature and humidity is provided as tPW/tF on the respective pins.

4.10 PWM Conversion of Signal Output

Measurement data is linearized and compensated for temperature and supply voltage effects by the sensor. The provided pulse widths tPW_RH and tPW_Temp are translated into humidity and temperature values by the following formulae, respectively: 𝑡F ) %RH ( 4 ) 𝑇 = (− 45 − 17.5 0.8 + 175 0.8 ⋅ 𝑡𝑃𝑊_Temp 𝑡𝐹 ) °C ( 5 ) 𝑇 = (− 49 − 31.5 0.8 + 315 0.8 ⋅ 𝑡𝑃𝑊_Temp 𝑡𝐹 ) °F ( 6 )

4.11 Reset

A reset of the sensor can be achieved in three ways:

• I2C Soft reset: send the reset command described in Table 7.
• I2C general call: all devices on I2C bus are reset by sending the command 0x06 to the I2C address 0x00.
• Power down (incl. pulling SCL and SDA low)

5 Physical Specification

5.1 Package Description

SHT4xA is provided in an open -cavity dual flat no lead (DFN) package. The humidity sensor opening is centered on the top side of the package. The sensor chip is made of silicon, hosted on a copper lead frame and overmolded by an epoxy-based mold compound. Exposed bottom side of the leadframe with the metallic contacts is Ni/Pd/Au coated, side walls are bare copper. Moisture sensitivity level (MSL) of 1 according to IPC/JEDEC J -STD-020 is achieved. It is recommended to process the sensors within one year after date of delivery. VDD tF tPW

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5.2 Package Outline – Standard Package

Figure 10 Dimensional drawing of SHT4xA including package tolerances (units mm).

5.3 Package Outline – Package with Wettable Flanks

Figure 11 Dimensional drawing of SHT4xA with wettable flanks, including package tolerances (units mm).

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5.4 Land Pattern

The land pattern is recommended to be designed according to the used PCB and soldering process together with the physical outer dimensions of the sensor. For reference, the land pattern used with Sensirion’s PCBs and soldering processes is given in Figure 12. It is suitable for the DFN with wettable flanks and without wettable-flanks option. Sensirion recommends to not solder the central die pad because the sensor can reach higher temperatures upon heater activation. Figure 12: Recommended land pattern (in mm). Details can vary and depend on used PCBs and solder processes. There shall be no copper under the sensor other than at the pin pads.

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5.5 Pin Assignment & Laser Marking

1 SDA RH Serial data,

2 SCL T Serial clock,

unidirectional input T out

3 VDD Supply voltage

4 VSS Ground

Figure 13 Pin assignment (transparent top view). Dashed lines are only visible if sensor is viewed from below. The die pad is not directly connected to any pin. The laser marking consists of two lines, indicated in Figure 13. In the first line a filled circle serves as pin-1 indicator and is followed by “SH4”. The fourth character will indicate the accuracy class of this product (here “x” serves as place holder ). Last “A” indicates the automotive grade. In the second line, the first three characters specify the product characteristics according to positions 8, 9 and 10 of Table 9. The second three characters serve as internal batch tracking code.

5.6 Thermal Information

Heater off, die pad soldered (K/W) Heater on, die pad soldered (K/W) Heater off, die pad not solder. (K/W) Heater on, die pad not solder. (K/W) DFN DFN+WF DFN DFN+WF DFN DFN+WF DFN DFN+WF 𝑅𝜃𝐽𝐴 Junction-to-ambie. thermal resistance 246 258 308 329 297 322 357 390 𝑅𝜃𝐽𝐶 Junction-to-case thermal resistance 189 183 255 252 191 188 257 254 𝑅𝜃𝐽𝐵 Junction-to-board thermal resistance 159 177 225 242 193 219 258 284 Ψ𝐽𝐵 Junction-to-board characteriz. param. 159 171 223 242 191 213 254 282 Ψ𝐽𝑇 Junction-to-top characteriz. param. 38 35 105 104 44 42 112 111 Table 8 Typical values for thermal metrics. In the “heater on” columns a heater power of 200 mW was assumed. Soldering of the die pad is not recommended, therefore the two right hand side columns are bold. The sub-columns labelled “DFN+WF” display the results for the DFN package with soldered wettable flanks terminals. Values are based on simulation.

6 Quality and Material Contents

Qualification of SHT4xA is performed based on the AEC Q100 qualification test method. Qualification pending. The device is fully RoHS and WEEE compliant, e.g. free of Pb, Cd, and Hg. For general remarks of best practice in processing humidity sensor please refer to (Sensirion, Handling Instructions for Humidity Sensors, 2020).

7 Tape and Reel Packaging

All specifications for the tape and reel packaging can be found on Figure 14. Reel diameters are 13 inch and 8 inch for the 10k and the 2.5k packaging sizes, respectively.

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8 Product Name Nomenclature

position value(s) explanation

1 S Sensirion

2 H humidity signal

3 T temperature signal

4 4 fourth product generation 5 0 base accuracy improved accuracy

6 A automotive version

A B F I2C interface with 0x44 address I2C interface with 0x45 address PWM Interface 9 D W DFN package DFN package with wettable flanks 10 1 reserved

11 B blank package without membrane

13 R tape on reel packaging

reel contains 2’500 pieces reel contains 10’000 pieces Table 9 SHT4xA product name nomenclature.

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9 Ordering Information

Material Description Material Number Details Quantity (pcs) SHT40A-AD1B-R2 3.000.546 base RH&T accuracy, 0x44 I2C addr. 2’500 SHT40A-AD1B-R3 3.000.672 base RH&T accuracy, 0x44 I2C addr. 10’000 SHT40A-FD1B-R2 3.000.676 base RH&T accuracy, PWM interface 2’500 SHT40A-FD1B-R3 3.000.673 base RH&T accuracy, PWM interface 10’000 SHT40A-AW1B-R2 3.000.677 base RH&T accuracy, 0x44 I2C addr., wettable flanks 2’500 SHT40A-AW1B-R3 3.000.674 base RH&T accuracy, 0x44 I2C addr., wettable flanks 10’000 SHT41A-AD1B-R2 3.000.551 improved RH&T accuracy, 0x44 I2C addr. 2’500 SHT41A-AD1B-R3 3.000.624 improved RH&T accuracy, 0x44 I2C addr. 10’000 SHT41A-AW1B-R2 3.000.552 improved RH&T accuracy, 0x44 I2C addr., wettable flanks 2’500 SHT41A-AW1B-R3 3.000.675 improved RH&T accuracy, 0x44 I2C addr., wettable flanks 10’000 Table 10 SHT4xA ordering options.

10 Bibliography

Date Version Page(s) Changes January 2022 1 All First release Updated drift specification in Table 1 Updated max. current in Table 3 Updated formula (4) and PWM description July 2022 2 3 Added SnapEDA link in section 1 Corrected typo in caption of Figure 7 Corrected erratum in caption of Table 7: old: “… valid for VDD=3.3V” new: “… valid for VDD=5V” Introduced new section 5.3 describing wettable flanks pack.

www.sensirion.com / D1 Version 2 – July 2022 18/18 Important Notices Warning, Personal Injury Do not use this product as safety or emergency stop devices or in any other application where failure of the product could re sult in personal injury. Do not use this product for applications other than its intended and authorized use. Before installing, handling, using or servicing this product, please consult the data sheet and application notes. Failure to comply with these instructio ns could result in death or serious injury. If the Buyer shall purchase or use SENSIRION products for any unintended or unauthorized application, Buyer shall defend, indemnify and hold harmless SENSIRION and its officers, employees, subsidiaries, affiliates and distributors against all claims, costs, dam ages and expenses, and reasonable attorney fees arising o ut of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if SENSIRION shall be allegedly negligent with respect to the design or the manufacture of the product. ESD Precautions The inherent design of this component causes it to be sensitive to electrostatic discharge (ESD). To prevent ESD -induced damage and/or degradation, take customary and statutory ESD precautions when handling this product. See application note “ESD, Latchup and EMC” for more information. Warranty SENSIRION warrants solely to the original purchaser of this product for a period of 12 months (one year) from the date of del ivery that this product shall be of the quality, material and workmanship defined in SENSIRION’s pub lished specifications of the product. Within such period, if proven to be defective, SENSIRION shall repair and/or replace this product, in SENSIRION’s discretion, free of charge to the Buyer, provided that:

• notice in writing describing the defects shall be given to SENSIRION within fourteen (14) days after their appearance;
• such defects shall be found, to SENSIRION’s reasonable satisfaction, to have arisen from SENSIRION’s faulty design, material, or workmanship;
• the defective product shall be returned to SENSIRION’s factory at the Buyer’s expense; and
• the warranty period for any repaired or replaced product shall be limited to the unexpired portion of the original period. This warranty does not apply to any equipment which has not been installed and used within the specifications recommended by SENSIRION for the intended and proper use of the equipment. EXCEPT FOR THE WARRANTIES EXPRESSLY SET FORTH HEREIN, SENSIRION MAKES N O WARRANTIES, EITHER EXPRESS OR IMPLIED, WITH RESPECT TO THE PRODUCT. ANY AND ALL WARRANTIES, INCLUDING WITHOUT LIMITATION, WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE EXPRESSLY EXCLUDED AND DECLINED. SENSIRION is only liable for defects of this product arising under the conditions of operation provided for in the data sheet and proper use of the goods. SENSIRION explicitly disclaims all warranties, express or implied, for any period during which the goods are operated or stored not in accordance with the technical specifications. SENSIRION does not assume any liability arising out of any application or use of any product or circuit and specifically disclaims any and all liability, including without limitation consequential or incidental damages. All operating parameters, including without limitation recommended parameters, must be validated for each customer’s applications by customer’s technical experts. Recommended parameters can an d do vary in different applications. SENSIRION reserves the right, without further notice, (i) to change the product specifications and/or the information in this document and (ii) to improve reliability, functions and design of this product. Copyright © 2022, by SENSIRION. CMOSens® is a trademark of Sensirion. All rights reserved Headquarters and Subsidiaries Sensirion AG Laubisruetistr. 50 CH-8712 Staefa ZH Switzerland phone: +41 44 306 40 00 fax: +41 44 306 40 30 info@sensirion.com www.sensirion.com Sensirion Inc., USA phone: +1 312 690 5858 info-us@sensirion.com www.sensirion.com Sensirion Korea Co. Ltd. phone: +82 31 337 7700~3 info-kr@sensirion.com www.sensirion.com/kr Sensirion Japan Co. Ltd. phone: +81 3 3444 4940 info-jp@sensirion.com www.sensirion.com/jp Sensirion China Co. Ltd. phone: +86 755 8252 1501 info-cn@sensirion.com www.sensirion.com/cn Sensirion Taiwan Co. Ltd phone: +886 3 5506701 info@sensirion.com www.sensirion.com To find your local representative, please visit www.sensirion.com/distributors