Semiconductor integrated circuit device
AssigneeHitachi, Ltd.
InventorsKumiko Takikawa, Satoshi Tanaka, Masumi Kasahara
Life of this patent
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Abstract
Into an internal circuit to operate in a high-frequency band, there is incorporated a protective circuit of a multistage connection which is constructed to include a plurality of diode-connected transistors having a low parasitic capacity and free from a malfunction even when an input signal higher than the power supply voltage is applied. Into an internal circuit to operate in a low-frequency band, there is incorporated a protective circuit which is constructed to include one diode-connected transistor. The protective circuits include two lines of protective circuit, in which the directions of electric currents are so reversed as to protect the internal circuits against positive/negative static electricities.
Claims11
A semiconductor integrated circuit device including
- a plurality of internal circuits for processing signals individually;
- and
- a plurality of signal lines connected individually with said internal circuits, a first voltage line for feeding a first voltage to said internal circuits, and a second voltage line for feeding a second voltage to said internal circuits, comprising:
- a first protective circuit connected between the signal lines and said first voltage line of each of said internal circuits for allowing an electric current to flow from said first voltage line to said signal lines at a protection time against an electrostatic breakdown;
- a second protective circuit connected between the signal lines and said second voltage line of each of said internal circuits for allowing an electric current to flow from said signal lines to said second voltage line at a protection time against an electrostatic breakdown;
- a third protective circuit connected between the signal lines and said first voltage line of each of said internal circuits for allowing an electric current to flow from said signal lines to said first voltage line at a protection time against an electrostatic breakdown;
- and
- a fourth protective circuit connected between the signal lines and said second voltage line of each of said internal circuits for allowing an electric current to flow from said second voltage line to said signal lines at a protection time against an electrostatic breakdown.
Dependencies are inferred from the claim text.