Apparatus and method of feeding internal calibration signal through electro-static discharge protection circuitry

An electronic apparatus with calibration, comprising:

• a processing circuit for processing an input signal received at an input node;
• at least an electro-static discharge (ESD) protection unit, coupled between the input node and a voltage supply node, for dissipating ESD pulses at the input node, the ESD protection unit comprising:
• a MOS transistor, comprising:
• a gate, coupled to a control signal;
• a first terminal, coupled to the input node;
• a body;
• and
• a second terminal, coupled to the body;
• and
• at least a diode coupled to the MOS transistor in series;
• wherein the MOS transistor receives a calibration signal inputted to the second terminal and selectively passes the calibration signal as the input signal to the processing circuit according to the control signal.

A method for calibrating an electronic apparatus, comprising:

• providing a processing circuit, and utilizing the processing circuit to process an input signal received at an input node;
• coupling at least an electro-static discharge (ESD) protection unit between the input node and a voltage supply node, and utilizing the ESD protection circuit to dissipate ESD pulses at the input node;
• coupling a switch unit to the ESD protection unit;
• in a calibration mode, switching on the switch unit for passing a calibration signal as the input signal to the processing circuit through the ESD protection unit;
• and
• in a normal mode, switching off the switch unit according to the control signal.

A method for calibrating an electronic apparatus, comprising:

• providing a processing circuit, and utilizing the processing circuit to process an input signal received at an input node;
• coupling at least an electro-static discharge (ESD) protection unit between the input node and a voltage supply node, for dissipating ESD pulses at the input node, the ESD protection unit comprising:
• a MOS transistor, comprising:
• a gate, coupled to a control signal;
• a first terminal, coupled to the input node;
• a body;
• and
• a second terminal, coupled to the body;
• and
• at least a diode coupled to the MOS transistor in series;
• in a calibration mode, switching on the MOS transistor for passing a calibration signal inputted into the second terminal as the input signal to the processing circuit according to the control signal;
• and
• in a normal mode, switching off the MOS transistor according to the control signal.