Fast transmission gate switch

A switching device for switching signals in a bi-directional manner along a bus of a printed circuit board, the switching device comprising:

• a package containing an integrated circuit device that includes a first plurality of field effect transistors and a driver circuit, each of the first plurality of transistors having an internal resistance Ri and an internal capacitance Ci, each of the first plurality of transistors including a first input/output terminal, a second input/output terminal and a control terminal, the driver circuit having an output terminal coupled to the control terminal of each of the first plurality of transistors;
• multiple first input/output leads directly connected to corresponding first input/output terminals and extending external to the package, the first input/output leads being connected to corresponding bus lines of the bus of the printed circuit board;
• multiple second input/output leads directly connected to corresponding second input/output terminals and extending external to the package, the second input/output leads being connected to corresponding bus lines of the bus of the printed circuit board, each of the bus lines having a bus capacitance Cb, wherein Cb is finite and greater than Ci, wherein Ri (Ci+Cb) is greater than zero and less than 6.5 nanoseconds;
• and
• a control lead coupled to an input terminal of the driver circuit, the control lead extending external to the package, wherein the first plurality of transistors are turned on and off in response to a control signal applied to the control lead, the first plurality of transistors being configured to pass signals in a bi-directional manner on the bus when the first plurality of transistors are turned on, and the first plurality of transistors being configured to block signals on the bus when the first plurality of transistors are turned off.

A digital system comprising:

• a printed circuit board having a bus with a bus capacitance Cb;
• a first logic device mounted on the printed circuit board and coupled to the bus;
• a second logic device mounted on the printed circuit board and coupled to the bus;
• a package containing an integrated circuit device that includes a first field effect transistor and a driver circuit, the first transistor having an internal resistance Ri and an internal capacitance Ci, wherein Ci is less than Cb, and wherein (Ci+Cb) is greater than zero and less than 6.5 nanoseconds, the first transistor including a first input/output terminal, a second input/output terminal and a control terminal, the driver circuit having an output terminal coupled to the control terminal of the first transistor;
• a first input/output lead directly connected to the first input/output terminal and extending external to the package, the first input/output lead being connected to the first logic device by the bus of the printed circuit board;
• a second input/output lead directly connected to the second input/output terminal and extending external to the package, the second input/output lead being connected to second logic device by the bus of the printed circuit board,;
• and
• a control lead coupled to an input terminal of the driver circuit, the control lead extending external to the package, wherein the first transistor is turned on and off in response to a control signal applied to the control lead, the first transistor being configured to pass signals in a bi-directional manner between the first and second logic devices on the bus when the first transistor is turned on, and the first transistor being configured to block signals between the first and second logic devices on the bus when the first transistor is turned off.