datasheetbank_Logo
Integrated circuits, Transistor, Semiconductors Search and Datasheet PDF Download Site

1-100645-01 View Datasheet(PDF) - Sensitron

Part Name
Description
View to exact match
1-100645-01
SENSITRON
Sensitron SENSITRON
1-100645-01 Datasheet PDF : 12 Pages
1 2 3 4 5 6 7 8 9 10 Next Last
Datasheet SHT21
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 SHT2x 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
VDD to VSS
-0.3
Digital IO Pins (SDA, SCL)
to VSS
-0.3
Input Current on any Pin -100
max Units
5
V
VDD + 0.3 V
100
mA
Table 3 Electrical absolute maximum ratings
ESD immunity is qualified according to MIL STD 883E,
method 3015 (Human Body Model at 2 kV). Latch-up
immunity is provided at a force current of 100mA with
Tamb = 80°C according to JEDEC78A. 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 10.
Parameter
Output Low
Voltage, VOL
Output High
Voltage, VOH
Output Sink
Current, IOL
Input Low
Voltage, VIL
Input High
Voltage, VIH
Input Current
Conditions min typ max Units
VDD = 3.0 V,
-4 mA < IOL < 0mA
0
- 0.4 V
70%
VDD
-
VDD
V
- - -4 mA
0
-
30%
VDD
V
70%
VDD
-
VDD
V
VDD = 3.6 V,
VIN = 0 V to 3.6 V
-
- ±1 uA
Table 4 DC characteristics of digital input/output pads. VDD =
2.1 V to 3.6 V, T = -40 °C to 125 °C, unless otherwise noted.
1/fSCK
tSCKH
tSCKL
tR
tF
SCL
tSU SDA valid write tHD
DATA IN
SDA
DATA OUT
SDA
SDA valid read
tVD
tF
70%
30%
70%
30%
tR
70%
30%
Figure 10 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. Both valid times
(SDA read and SDA write) refer to the left SCL toggle.
Parameter
min typ max Units
SCL frequency, fSCL
0 - 0.4 MHz
SCL High Time, tSCLH
0.6 - - µs
SCL Low Time, tSCLL
1.3 - - µs
SDA Set-Up Time, tSU
100 - - ns
SDA Hold Time, tHD
0 - 900 ns
SDA Valid Time, tVD
0 - 400 ns
SCL/SDA Fall Time, tF
0 - 100 ns
SCL/SDA Rise Time, tR
0 - 300 ns
Capacitive Load on Bus Line, CB 0 - 400 pF
Table 5 Timing specifications of digital input/output pads for I2C
fast mode. Entities are displayed in Figure 10. VDD = 2.1V to
3.6V, T = -40°C to 125°C, unless otherwise noted.
5 Communication with Sensor
SHT21 communicates with true I2C protocol. For
information on I2C beyond the information in the following
Sections please refer to the following website:
http://www.standardics.nxp.com/support/i2c/.
Please note that all sensors are set to the same I2C
address, as defined in Section 5.3. 15
Furthermore, please note, that Sensirion provides a
sample code on its home page – compare
www.sensirion.com/sht21.
5.1 Start Up Sensor
As a first step, the sensor is powered up to the chosen
supply voltage VDD (between 2.1 V and 3.6 V). After
power-up, the sensor needs at most 15 ms, while SCL is
high, for reaching idle state, i.e. to be ready accepting
15 For sensors with alternative I2C address please contact Sensirion via
info@sensirion.com.
www.sensirion.com
Version 1.0 – January 2010
6/12
 

Share Link: 

datasheetbank.com [ Privacy Policy ] [ Request Datasheet ] [ Contact Us ]