Apparatus and methods for self-biasing differential signaling circuitry having multimode output configurations for low voltage applications

An integrated circuit comprising:

• a differential signaling circuit including:
• differential signaling circuitry having at least one input and at least one output;
• a plurality of switches configured to selectively couple a supply voltage to the at least one output dependent on a mode of operation of the differential signaling circuitry;
• a switch control biasing circuit operatively coupled to a switch of the plurality of switches and to the at least one output of the differential signaling circuitry, and configured to provide a switch control biasing voltage to control a state of the switch based on a voltage level of the at least one output;
• and
• a bulk biasing circuit operatively coupled to the switch and configured to selectively provide a bulk biasing voltage to the switch based on the voltage level of the at least one output.

A multimode differential signal circuit comprising:

• an output terminal;
• a switch contol biasing circuit operative to generate a control biasing voltage;
• a switch circuit including:
• a first terminal operatively coupled to a voltage supply;
• a second terminal coupled to the output terminal;
• and
• a control terminal operatively responsive to the control biasing voltage to selectively control electrical conduction between the first terminal to the second terminal, wherein the control biasing voltage is dependant on a voltage level of the second terminal;
• and
• wherein the switch control biasing circuit includes:
• a voltage divider circuit coupled between the output terminal and a common potential, the divider circuit having a tap to supply a divived voltage level;
• and
• a biasing transistor having a first biasing transistor terminal coupled to the output terminal, a second biasing transistor terminal coupled to the tap and the control terminal of the switch, and a third biasing transistor terminal coupled to the voltage supply.

A multimode differential signaling circuit comprising:

• an output terminal;
• a switch control biasing circuit operative to generate a control biasing voltage;
• a switching circuit including;
• a bulk;
• a first terminal operatively coupled to a voltage supply;
• a second terminal coupled to the output terminal;
• and
• a control terminal operatively responsive to the control biasing voltage to selectively control electrical conduction between the first terminal to the second terminal, wherein the control biasing voltage is dependent on a voltage level of the second terminal;
• and
• a bulk biasing circuit operatively coupled to bulk and configured to selectively provide a bulk biasing voltage to the bulk based on a voltage level of the output terminal.