Electronic Components Datasheet Search |
|
STS21 Datasheet(PDF) 5 Page - List of Unclassifed Manufacturers |
|
STS21 Datasheet(HTML) 5 Page - List of Unclassifed Manufacturers |
5 / 12 page Datasheet STS21 www.sensirion.com Version 2 – December 2011 5/12 consists of fully static logic there is no minimum SCL frequency. 3.3 Serial SDA (SDA) The SDA pin is used to transfer data in and out of the sensor. For sending a command to the sensor, SDA is valid on the rising edge of SCL and must remain stable while SCL is high. After the falling edge of SCL the SDA value may be changed. For safe communication SDA shall be valid tSU and tHD before the rising and after the falling edge of SCL, respectively – see Figure 9. For reading data from the sensor, SDA is valid tVD after SCL has gone low and remains valid until the next falling edge of SCL. Figure 8 Typical application circuit, including pull-up resistors RP and decoupling of VDD and VSS by a capacitor. To avoid signal contention the micro-controller unit (MCU) must only drive SDA and SCL low. External pull-up resistors (e.g. 10kΩ), are required to pull the signal high. For the choice of resistor size please take bus capacity requirements into account (compare Table 5). It should be noted that pull-up resistors may be included in I/O circuits of MCUs. See Table 4 and Table 5 for detailed I/O characteristic of the sensor. 4 Electrical Characteristics 4.1 Absolute Maximum Ratings The electrical characteristics of STS21 are defined in Table 1. The absolute maximum ratings as given in Table 3 are stress ratings only and give additional information. Functional operation of the device at these conditions is not implied. Exposure to absolute maximum rating conditions for extended periods may affect the sensor reliability (e.g. hot carrier degradation, oxide breakdown). Parameter min max Units VDD to VSS -0.3 5 V Digital I/O Pins (SDA, SCL) to VSS -0.3 VDD + 0.3 V Input Current on any Pin -100 100 mA Table 3 Electrical absolute maximum ratings ESD immunity is qualified according to JEDEC JESD22- A114 method (Human Body Model at 4kV), JEDEC JESD22-A115 method (Machine Model 200V) and ESDA ESD-STM5.3.1-1999 and AEC-Q100-011 (Charged Device Model, 750V corner pins, 500V other pins). Latch- up immunity is provided at a force current of 100mA with Tamb = 125°C according to JEDEC JESD78. For exposure beyond named limits the sensor needs additional protection circuit. 4.2 Input / Output Characteristics The electrical characteristics such as power consumption, low and high level input and output voltages depend on the supply voltage. For proper communication with the sensor it is essential to make sure that signal design is strictly within the limits given in Table 4 & 5 and Figure 9. Parameter Conditions min typ max Units Output Low Voltage, VOL VDD = 3.0 V, -4 mA < IOL < 0mA 0 - 0.4 V Output High Voltage, VOH 70% VDD - VDD V Output Sink Current, IOL - - -4 mA Input Low Voltage, VIL 0 - 30% VDD V Input High Voltage, VIH 70% VDD - VDD V Input Current VDD = 3.6 V, VIN = 0 V to 3.6 V - - ±1 uA Table 4 DC characteristics of digital input/output pads. VDD = 2.1V to 3.6V, T = -40°C to 125°C, unless otherwise noted. Figure 9 Timing Diagram for Digital Input/Output Pads, abbreviations are explained in Table 5. SDA directions are seen from the sensor. Bold SDA line is controlled by the sensor, plain SDA line is controlled by the micro-controller. Note that SDA valid read time is triggered by falling edge of anterior toggle. SCL 70% 30% tSCLL 1/fSCL tSCLH tR tF SDA 70% 30% tSU tHD SDA valid read DATA IN tR SDA 70% 30% DATA OUT tVD tF SDA valid write SDA SCL GND VDD MCU (master) RP RP SCL OUT SDA OUT SDA IN SCL IN STS21 (slave) |
Similar Part No. - STS21 |
|
Similar Description - STS21 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |