Interface Circuit and Method for Enabling an Output Driver of the Interface Circuit

An interface circuit, comprising:

• an interface terminal configured to connect to an interface line for communication with a communication partner;
• a standard-level generating circuit configured to hold a standard level at the interface terminal when no active signal is present thereat;
• a checking circuit configured to test whether a current level at the interface terminal is within a tolerance range with respect to the standard level and outputting a corresponding test result;
• an enable circuit configured to receive the test result and enable an output mode of the interface when the current level is within the tolerance range and the interface circuit does not apply an active signal to the interface terminal.

A method for enabling an output mode of an interface with an interface terminal which is configured to connect to an interface line for communication with a communication partner, comprising:

• holding a standard level at the interface terminal when no active signal is present thereat;
• testing whether a current level at the interface terminal is within a tolerance range with respect to the standard level;
• generating a corresponding test result in response to the testing;
• and
• enabling the output mode of the interface when the current level is within the tolerance range and the interface circuit does not apply an active signal to the interface terminal.