[SOLVED] what is the voltage level of UART in PC?

[RAHUL_KUMAR]

most of the PC's UART voltage level range is from 13v to -13v ? is it ??

 

[betwixt]

Somewhere around there. It is usually assumed to be +12V/-12V at the RS232 interface but it can be more than that.

Brian.

 

[FvM]

Standard specifies a range of +/-3V to +/-15V as far as I know. Maximum level to be tolerated by receivers is +/-25V.

3.3V supplied driver ICs like MAX3323 have typically +/- 5.4V output.

 

[andre_luis]

Nowardays, desktop and laptop PCs no longer come with native serial port; it is often necessary to attach USB converters, which commonly have a voltage ranging much below 12v.