Circuit arrangement for electrically insulated transmission of electrical signal with optical coupler has evaluation circuit that only recognizes pulse width modulated signal as valid if terminating signal has been received

摘要

The arrangement has an optical coupler (1), a converter stage (13) connected to the input of the optical coupler that converts the electrical signal (Uin) into a pulse width modulated signal and feeds it to the optical coupler, a logic circuit (14) that generates a terminating signal and feeds it to the optical coupler when the conversion has completely finished and an evaluation circuit (15) that only recognizes the pulse width modulated signal as valid if the terminating signal has been received.