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US 5,508,654 AGranted
Transistor circuits with a terminal for receiving high voltages and signals
AssigneeNEC Corporation
InventorHiroyuki Kobatake
Life of this patent
Estimating the term…
Abstract
A transistor circuitry keeps its constituent transistors from being forward biased to prevent injection of large currents into the transistor substrates, and like problems. The transistor circuitry achieves this result with a control circuit which generates a substrate control voltage and switching transistors which are prevented from receiving a high constant current voltage from an input terminal until the substrate control voltage is raised up to and held at a desired voltage level.
Claims38
A transistor circuitry comprising:
- an input terminal for receiving both an input signal having a voltage ranging from a first voltage level to a second voltage level higher than said first voltage level and for subsequently receiving a high constant voltage having a third voltage level higher than said second voltage level;
- a first output terminal through which an output signal is outputted;
- an input circuit electrically connected between said input terminal and said first output terminal for fetching said input signal from said input terminal and for subsequently supplying said output signal to said output terminal;
- a second output terminal through which said high constant voltage having said third voltage level is outputted;
- a power source voltage terminal through which a power source voltage having a same voltage level as said second voltage level is supplied;
- a control circuit electrically connected between said input terminal and said power source voltage terminal for generating a substrate control voltage that is held at said second voltage level upon receipt of said input signal by said input terminal and that is subsequently gradually increased up to said third voltage level when said input signal switches into said high constant voltage to hold said substrate control voltage at said third voltage level;
- a first switching transistor electrically connected to said second output terminal, said first switching transistor having a substrate that is electrically connected to said control circuit for receiving said substrate control voltage;
- and
- a second switching transistor electrically connected between said input terminal and said first switching transistor to transmit said high constant voltage from said input terminal through said first and second switching transistors to said second output terminal wherein said second switching transistor is controlled to be held in an off state to prevent said first switching transistor from receiving said high constant voltage until said substrate control voltage is raised up to and held at said third voltage level.
6 more elements
A transistor circuitry comprising:
- an input terminal for receiving both an input signal having a voltage in the range from a first voltage level and a second voltage level higher than said first voltage level and for subsequently receiving a high constant voltage having a third voltage level higher than said second voltage level;
- a first output terminal through which said high constant voltage having said third voltage level is outputted;
- a power source voltage terminal through which a power source voltage having the same voltage level as said second voltage level is supplied;
- a control circuit electrically connected between said input terminal and said power source voltage terminal for generating a substrate control voltage that is maintained at said second voltage level upon receipt of said input signal by said input terminal and that is subsequently gradually increased up to said third voltage level when said input signal switches to said high constant voltage to hold said substrate control voltage at said third voltage level;
- a first switching transistor electrically connected to said first output terminal, said first switching transistor having a substrate that is electrically connected to said control circuit for receiving said substrate control voltage;
- and
- a second switching transistor electrically connected between said input terminal and said first switching transistor to transmit said high constant voltage from said input terminal through said first and second switching transistors to said first output terminal wherein said second switching transistor is so controlled as to be held in an off state to prevent said first switching transistor from receiving said high constant voltage until said substrate control voltage is raised up to and held at said third voltage level.
4 more elements
Dependencies are inferred from the claim text.