Transmission gate circuit
AssigneeTexas Instruments Incorporated
InventorsKevin Ovens, Clive Bittlestone, Bob Helmick
Life of this patent
Estimating the term…
Abstract
A transmission gate circuit 20 includes a pull-up control circuit 15, a pull-down control circuit 17, and an electrical switch 19. Pull-up control circuit 15 and electrical switch 19 provide fast, complete transition from low-to-high at the output of circuit 20 thus improving circuit 20 speed as well as improving the switching speed of subsequent gates. Pull-down control circuit 17 and electrical switch 19 provide complete transition from high-to-low at the output of circuit 20. Transmission gate circuit 17 also provides increased drive such that circuit 20 may provide a gate fanout increase of 3X.
Claims8
A transmission gate circuit, comprising:
- an electrical switch having a first terminal connected to a voltage source, a second terminal, and a third terminal forming a circuit output;
- a pull-up control circuit having a first terminal forming a circuit input and a second terminal connected to the second terminal of the electrical switch;
- and
- a pull-down control circuit having a first terminal connected to the circuit input and a second terminal connected to the circuit output wherein the pull-down control circuit passes the input to the output when the input transitions from low to high during a final phase of output signal transition.
A high speed transmission gate, comprising:
- a first CMOS transmission gate having a first terminal forming a circuit input, a first control terminal connected to a first enable voltage signal, a second control terminal connected to a second enable voltage signal, and a second terminal;
- a second CMOS transmission gate having a first terminal connected to the circuit input, a first control terminal connected to the first enable voltage signal, a second control terminal connected to the second enable voltage signal, and a second terminal forming a circuit output, wherein second CMOS transmission gate passes the input to the output when the input transitions from low to high during a final phase of output signal transition;
- and
- a bipolar transistor having a collector connected to a power supply, a base connected to the second terminal of the first CMOS transmission gate, and an emitter connected to the circuit output.
Dependencies are inferred from the claim text.