An asynchronous level shifter electronic circuit including: a transmitter, which can be coupled to a first voltage and generates a communication signal; a receiver, which can be coupled to a second voltage; and a capacitive coupling stage, which receives the communication signal and supplies a corresponding filtered signal to the receiver. The receiver includes: a threshold device, which has an input terminal and an output terminal and switches an electrical quantity on the output terminal between a first value and a second value, as a function of corresponding transitions through a threshold of a first intermediate signal present on the input terminal, to generate a second intermediate signal; and a biasing circuit, which generates the first intermediate signal to have a d.c. component, which is a function of the second intermediate signal, and superposed on which is a variable component, which is a function of the filtered signal.