STM8L151C8T6 LQPF48 PIN13/VLCD how to connect？ When I'm not using VLCD function，this pin is must be tied to VDD？ What would happen if there was NC？

[cguol]

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[Sisto Zànier]

MUST means MUST and not optionally, so on STM8L151xx Devices, the VLCD pin MUST to be tied to MCU VDD.