Electronic – Will a 3V3 rated UART be damaged by applying 5V signals


If I have a device specified for 3.3V operation and I connect a 5V level TTL signal to it ? Will it's UART ports be damaged or not ?

I have a WiFi module and I want to know if its UART ports will have been damaged by applying 5 Volt signal levels during an experiment or if there is still hope that it has not been damaged ?

This WiFi unit

This may be the manual

Best Answer

While there is no yes/no answer to whether your particular device has a damaged UART port many devices that are specified for 3.3V operation can have their I/O lines damaged by applying 5V logic levels. Best practice is to check the datasheet and confirm the particular device is 5V tolerant and if not mentioned in the specifications either assume it's not and use 3.3V logic or contact the manufacturer for clarification.