UART signals toggle at what voltage level?

The correct answer, which indicates that UART signals toggle at 5 V, is based on the standard voltage levels defined for UART (Universal Asynchronous Receiver/Transmitter) communication. UART is a widely used serial communication protocol that allows asynchronous data transfer between devices.

In traditional TTL (Transistor-Transistor Logic) logic levels, which is common in UART implementations, a signal is typically considered to be a 'high' state when it is around 2.5 V to 5 V, with 5 V being the standard definition for 'high'. When the signal is below a certain threshold, it is considered a 'low' state, usually around 0 V. Therefore, most UART configurations use 5 V for logical high outputs.

This voltage level is critical because it ensures adequate noise margins, allowing for reliable data transmission over different lengths and conditions of cable. The use of 5 V for UART helps ensure compatibility with a variety of microcontrollers and integrated circuits that are designed to operate at that voltage, making UART a versatile choice in electronic design.

Other voltage levels listed, such as 3 V, 7 V, and 12 V, are not standard for typical UART communication and may correspond to other types of signaling systems or