BiCMOS electrostatic discharge power clamp
AssigneeUnited Microelectronics Corp.
InventorShiao-Shien Chen
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Abstract
A BiCMOS electrostatic discharge (ESD) protecting circuit is triggered by a bipolar junction transistor (BJT) for achieving ESD protection. Due to the layout area of the BJT ESD protecting circuit being smaller than the layout area of an RC circuit, layout area can be reduced. Moreover, the BJT reduces leakage current problems and has a lower triggering voltage. Therefore, the BJT in the ESD protecting circuit can effectively reduce problems of a higher triggering ESD voltage and leakage current.
Claims25
An electrostatic discharge (ESD) protecting circuit for a BiCMOS, said ESD protecting circuit comprising:
- a metal oxide semiconductor (MOS) transistor;
- a bipolar junction transistor (BJT), wherein a base of said BJT is an open terminal said BJT is an N-type BJT, and a sinker is below a collector of said BJT to collect a current;
- and
- a resistor being connected with said BJT in a series connection and said series connection being further connected with said MOS transistor in parallel, wherein a contact of said resistor and said BJT is connected with said MOS transistor to make a voltage across said resistor drive an electrostatic current flowing through a parasitic BJT within said MOS transistor.
A method for electrostatic discharge (ESD) protection of a BiCMOS, said method comprising:
- passing an electrostatic current across a bipolar junction transistor (BJT) to make a voltage higher than a triggering voltage to lead out electrostatic current, wherein a base said BJT is an open terminal, said BJT is an N-type BJT, and a sinker is below a collector of said BJT to collect a current;
- providing said BJT with a resistor in a series connection;
- providing said series connection with a metal oxide semiconductor (MOS) transistor in parallel;
- and
- providing said resistor connected with said MOS transistor to make a voltage across said resistor drive said electrostatic current flowing through a parasitic BJT within said MOS transistor.
Dependencies are inferred from the claim text.