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version 1.0 – December 2021

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3.4 Built-in Self-Test

With the sgp41_execute_self_test command, users can perform an on-chip self-test for, e.g., in-line or end-of-line production

testing. If this command is called when the sensor is in idle mode, the sensor returns to idle mode after the test (Figure 13). In

command), the hotplate remains switched on thereafter. It is not recommended to call this command during conditioning mode

(i.e., after calling the sgp41_execute_conditioning command). After 320 ms, the master can read a fixed data pattern (1 word +

CRC byte) to check if the test was successful or not.

Figure 13 Process flow for performing the built-in self-test.

3.5 Reading out The Sensor Serial Number

Every SGP41 sensor carries a unique serial number for identification purposes which is hard coded during sensor production.

This number can be read out by using the sgp4x_get_serial_number command at any time in idle mode (Figure 14). After 1 ms,

the chip responds with 3 words (each word followed by one CRC byte) which together constitute the serial number.

Figure 14 Process flow for reading out the serial number of the SGP41 sensor.

3.6 Sensor Start-up Behavior

The sensor starts powering-up after reaching the power-up threshold voltage of 1.7 V and enters idle mode after max. 0.6 ms.

In this state, the sensor is ready to receive commands from the master.