A digital input circuit includes a series connection of a current limiter and a switch having a switch control input coupled between a signal input and ground, and a logic level shifter coupled to the signal input and having a switch control output coupled to the switch control input and a signal output, where a maximum amplitude at the signal input is greater than a maximum amplitude at the signal output. A digital input method includes coupling an input signal to ground with a current limiter by closing an electronic switch, providing an output signal responsive to the input signal, where a maximum amplitude of the input signal is greater than a maximum amplitude of the output signal, by latching the output signal while the input signal is above a threshold voltage and opening the electronic switch after the output signal is latched.