High speed driver circuit with improved off transition feedback
First Claim
1. A driver circuit comprisinga driver transistor having a source, a gate, and a drain,a feedback transistor having a source, a gate, and a drain, said source being connected to said source of said driver transistor and said drain being connected to said gate of said driver transistor,an input terminal for receiving input signals,an output terminal connected to said source of said driver transistor and to said source of said feedback transistor,first conduction means for connecting said input terminal to said gate of said driver transistor, andsecond conduction means including delay circuitry for connecting said input terminal to said gate of said feedback transistor whereby a pulse transition on said input terminal turns-off said driver transistor, said turn-off being-delayed by momentary conduction of said feedback transistor.
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Accused Products
Abstract
A driver circuit has a single feedback transistor in the driver transistor well to provide a momentary feedback from source to gate and maintain conductance of the driver transistor during turnoff of the driver transistor and thus reduce ringing oscillation at the transistor source output. An enable/disable signal is applied to control conduction circuitry and the driver transistor and force the output to a high impedance state when the circuit is disabled. Clocked operation of the driver circuit is provided with circuitry merged with a latch. A terminal for receiving a global idd test signal controls circuitry removing power to the driver circuit and applying a ground potential to the driver output in response to the global idd test signal.
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Citations
15 Claims
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1. A driver circuit comprising
a driver transistor having a source, a gate, and a drain, a feedback transistor having a source, a gate, and a drain, said source being connected to said source of said driver transistor and said drain being connected to said gate of said driver transistor, an input terminal for receiving input signals, an output terminal connected to said source of said driver transistor and to said source of said feedback transistor, first conduction means for connecting said input terminal to said gate of said driver transistor, and second conduction means including delay circuitry for connecting said input terminal to said gate of said feedback transistor whereby a pulse transition on said input terminal turns-off said driver transistor, said turn-off being-delayed by momentary conduction of said feedback transistor.
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10. A driver circuit comprising
a driver transistor having a source, a gate, and a drain, a feedback transistor having a source, a gate, and a drain, said source being connected to said source of said driver transistor and said drain being connected to said gate of said driver transistor, an input terminal for receiving input signals, an output terminal connected to said source of said driver transistor and to said source of said feedback transistor, a first conduction path for connecting said input terminal to said gate of said driver transistor, and a second conduction path including delay circuitry for connecting said input terminal to said gate of said feedback transistor whereby a pulse transition on said input terminal turns-off said driver transistor, said turn-off being delayed by momentary conduction of said feedback transistor.
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15. In a driver circuit including a driver transistor having a source, a gate, and a drain formed in a doped well in a semiconductor body, a method of suppressing ringing when the driver transistor turns off comprising the step of
a) providing a feedback transistor in said well, said feedback transistor having a source, a gate, and a drain, said source being connected to said source of said driver transistor and said drain being connected to said gate of said driver transistor, an output terminal connected to said source of said driver transistor and to said source of said feedback transistor, b) providing a first conduction path for connecting an input terminal to said gate of said driver transistor, and c) providing a second conduction path including delay circuitry for connecting said input terminal to said gate of said feedback transistor whereby a pulse transition on said input terminal turns-off said driver transistor, said turn-off being delayed by momentary conduction of said feedback transistor.
Specification