Novel method to improve electrostatic discharge (esd) robustness

A chip, comprising:

• a pad;
• a driver having a first input, a second input, and an output, wherein the output of the driver is coupled to the pad;
• a pre-driver circuit, comprising:
• a first tri-state buffer having a data input, a control input, and an output, wherein the output of the first tri-state buffer is coupled to the first input of the driver;
• and
• a second tri-state buffer having a data input, a control input, and an output, wherein the output of the second tri-state buffer is coupled to the second input of the driver;
• and
• a trigger circuit, comprising:
• a resistor coupled between a first bus and a node, wherein the node is coupled to the control input of the first tri-state buffer and the control input of the second tri-state buffer;
• and
• a capacitor coupled between the node and a second bus.

A method for electrostatic discharge (ESD) protection of a chip including a driver, a first tri-state buffer, and a second tri-state buffer, wherein an output of the driver is coupled to a pad, an output of the first tri-state buffer is coupled to a first input of the driver, and an output of the second tri-state buffer is coupled to a second input of the driver, the method comprising:

• during a normal mode, driving the first input of the driver with a first data signal using the first tri-state buffer;
• during the normal mode, driving the second input of the driver with a second data signal using the second tri-state buffer;
• detecting an ESD event on the pad;
• and
• in response to detecting the ESD event, putting each of the first tri-state buffer and the second tri-state buffer in a high impedance output state.