SHT3X-DIS Datasheet, PDF(10/18 Page) List of Unclassifed Manufacturers

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SHT3X-DIS Datasheet, PDF (10/18 Pages) List of Unclassifed Manufacturers – Very fast start-up and measurement time

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Datasheet SHT3x-DIS

In order to achieve a full reset of the sensor without

removing the power supply, it is recommended to use

the nRESET pin of the SHT3x-DIS.

Interface Reset

If communication with the device is lost, the following

signal sequence will reset the serial interface: While

leaving SDA high, toggle SCL nine or more times. This

must be followed by a Transmission Start sequence

preceding the next command. This sequence resets the

interface only. The status register preserves its content.

Soft Reset / Re-Initialization

The SHT3x-DIS provides a soft reset mechanism that

forces the system into a well-defined state without

removing the power supply. When the system is in idle

state the soft reset command can be sent to the

SHT3x-DIS. This triggers the sensor to reset its system

controller and reloads calibration data from the

memory. In order to start the soft reset procedure the

command as shown in Table 13 should be sent.

It is worth noting that the sensor reloads calibration

data prior to every measurement by default.

Command

Soft Reset

Hex Code

0x30A2

Table 13 Soft reset command (Clear blocks are controlled by

the microcontroller, grey blocks by the sensor)

Reset through General Call

Additionally, a reset of the sensor can also be

generated using the âgeneral callâ mode according to

I2C-bus specification12. This generates a reset which is

functionally identical to using the nReset pin. It is

important to understand that a reset generated in this

way is not device specific. All devices on the same I2C

bus that support the general call mode will perform a

reset. Additionally, this command only works when the

sensor is able to process I2C commands. The

appropriate command consists of two bytes and is

shown in Table 14.

Reset through the nReset Pin

Pulling the nReset pin low (see Table 6) generates a

reset similar to a hard reset. The nReset pin is internally

connected to VDD through a pull-up resistor and hence

active low. The nReset pin has to be pulled low for a

minimum of 350 ns to generate a reset of the sensor.

Command

Code

Address byte

0x00

Second byte

0x06

Reset command using the

general call address

0x0006

123456789123456789

S General Call Address

Reset Command

General Call 1st byte

General Call 2nd byte

Table 14 Reset through the general call address (Clear

blocks are controlled by the microcontroller, grey blocks by

the sensor).

Hard Reset

A hard reset is achieved by switching the supply

voltage to the VDD Pin off and then on again. In order

to prevent powering the sensor over the ESD diodes,

the voltage to pins 1 (SDA), 4 (SCL) and 2 (ADDR) also

needs to be removed.

4.10 Heater

The heater can be switched on and off by command,

see table below. The status is listed in the status

condition).

Command

Heater Enable

Heater Disabled

Hex Code

MSB

LSB

0x30

Table 15 Heater command (Clear blocks are controlled by

the microcontroller, grey blocks by the sensor)

4.11 Status Register

The status register contains information on the

operational status of the heater, the alert mode and on

the execution status of the last command and the last

write sequence. The command to read out the status

the content can be found in Table 17.

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October 2015 - Version 1

10/18

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