Sensor communication discrete control considering EMC compliance for restraint control module

An electronic control unit comprising:

• a Peripheral Sensor Interface 5 (PSI5) communications interface configured to communicate with a remote sensor using a current-modulated signal with PSI5 compliance upon a two-wire interconnection, the PSI5 communications interface including:
• a signal driver configured to apply a signal voltage to a first signal terminal for driving current to the remote sensor via the two-wire interconnection;
• a second signal terminal providing a return path for the current;
• a resistor within the return path of the PSI5 communications interface to induce a balance voltage on the second signal terminal, wherein the balance voltage has a magnitude corresponding to a magnitude of the signal voltage and an opposite polarity thereof, and wherein the resistor is defined by a drain-source on resistance of a field effect transistor;
• and
• a switch configured to limit an amount of current between the second signal terminal and a ground.

A method for operating a Peripheral Sensor Interface 5 (PSI5) communications interface of an electronic control unit, the method comprising:

• applying a signal voltage to a first signal terminal of the PSI5 communications interface to drive a signal current to a remote sensor via a two-wire interconnection;
• receiving the signal current from the remote sensor by a second signal terminal of the PSI5 communications interface providing a return path for the signal current;
• inducing a balance voltage upon the second signal terminal by a resistor within the return path, wherein the balance voltage has a magnitude corresponding to a magnitude of the signal voltage and an opposite polarity thereof, and wherein the resistor is defined by a drain-source on resistance of a field effect transistor;
• and
• selectively changing a resistance of the resistor as a function of the signal voltage.