Driver circuit shared across operating modes and method for operating driver circuit

A driver circuit, comprising:

• a post driver, having a first supply terminal, a second supply terminal and an output terminal, the post driver comprising:
• a first switch, selectively coupled between the first supply terminal and a first node according to a control output;
• a first resistive element, coupled between the first node and the output terminal;
• and
• a second switch, selectively coupled between the second supply terminal and the first node according to the control output;
• and
• a pre-driver, coupled to the post driver, the pre-driver being configured to generate the control output according to a mode signal and a control input,
• wherein when the mode signal indicates that the driver circuit is configured to generate an output signal having a first voltage swing at the output terminal, the first supply terminal is coupled to a first voltage level, the first switch is selectively turned on according to the control output, and the second switch is turned off;
• when the mode signal indicates that the driver circuit is configured to generate the output signal having a second voltage swing less than the first voltage swing, each of the first supply terminal and the second supply terminal is coupled to a second voltage level, and each of the first switch and the second switch is selectively turned on according to the control output.