General protection of an integrated circuit against permanent overloads and electrostatic discharges
AssigneeSGS-Thomson Microelectronics S.A.
InventorFrancois Tailliet
Life of this patent
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Abstract
In an integrated circuit, a diode is interposed between the semiconductor substrate and the contact pad to an external bias voltage, and the substrate is biased at an internal voltage reference. Between each contact pad of the integrated circuit and semiconductor substrate, there is positioned a protection device against permanent overloads and a protection device against electrostatic discharges. By isolating the semiconductor substrate from the external voltages source and by placing a protection device between each contact pad and the substrate, a broad, general protection of the integrated circuit is obtained against all the destructive phenomena such as overloads, positive and negative overvoltages, polarity reversal and electrostatic discharges.
Claims15
An integrated circuit comprising:
- a semiconductor substrate with a first type of doping, and
- contact pads for the connection of internal functional nodes to external signals, including at least a first external voltage contact pad connected to provide a first internal voltage reference and a second external voltage contact pad connected to receive a second external voltage;
- said semiconductor substrate being biased at a second internal reference voltage which is different from said second external voltage, and comprising
- a diode connected between said semiconductor substrate and said second external voltage contact pad, wherein said diode is forward biased in a state of normal bias of said integrated circuit and is reverse biased in a state of reverse bias of said integrated circuit;
- a biasing resistor connected between said semiconductor substrate and said first internal voltage reference, and a respective protection device against overvoltages electrically interposed between each of said contact pads and said semiconductor substrate.
An integrated circuit comprising
- a semiconductor substrate with a first type of doping, and connected, through a current path which includes a biasing resistor, to be biased by a first external bias voltage and a second external bias voltage to an internal voltage reference which is different from said external voltages;
- a diode connected between said substrate and said second external bias voltage;
- a respective protection device against overvoltages electrically interposed between each of a plurality of contact pads and said semiconductor substrate;
- wherein said diode is forward biased when said first and second external bias voltages are connected with normal polarity, and is reverse biased when said first and second external bias voltages are connected with reversed polarity.
Dependencies are inferred from the claim text.