How to configure Undervoltage Alarm (UVA) of CLT01-38SQ7

[Central SUPPORT]

Hi, I use CLT01-38SQ7. In datasheet (DocID028182 Rev 1) is not clear to me how to use Vcs pin (24V sensor power supply sensing input) for UVA purpose.

In Figure 7. “Logic status of the SCLT3-8BQ7 power supply�? voltage ranges of Vcc and Vc are shown, but I do not understand how these values are determined, since they depend on the values of the voltage divider in the circuit Vcs (pin 14) and his input current.

                    

               

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[Central SUPPORT]

The Undervoltage Alarm (UVA) region is monitored by means of the pin Vcs. In fact, this is how you can set the alarm detection voltage via Rs and Rpd:

For example, with a resistor bridge containing Rs = 1.5 MΩ and Rpd = 120 kΩ will trigger UVA when Vcc drops below 17 V.

Please refer to Application note AN2846 “SCLT3-8 - guidelines for use in industrial automation applications�? where you can find more detailed information.