Circuit generating constant narrow-pulse-width bipolarity monocycles
View Patent ↗A mono-cycle generating circuit includes a multiplexer, a pulse generating circuit, and a buffer circuit. The multiplexer receives data of a logical 1 or a logical 0, determines whether to generate a positive mono-cycle or a negative mono-cycle, based upon the data, and outputs clock signals varying in time based upon the data. The pulse generating circuit is coupled to the multiplexer, receives the clock signals and generates a first series of pulses including an up-pulse preceding a down-pulse, or a second series of pulses including a down-pulse preceding an up-pulse, in response to the clock signals received by the multiplexer. The buffer circuit is coupled to the pulse generating circuit and includes a switch circuit and a common mode buffer. The switch circuit generates the positive mono-cycle or the negative mono-cycle, based upon whether the first series of pulses is received from the pulse generating circuit or the second series of pulses is received from the pulse generating circuit. The common mode buffer circuit is coupled to the switching circuit and reduces noise generated by the switch circuit.
1. A circuit generating an up-pulse and a down-pulse, comprising:
respective series of inverters comprising complementary transistors generating delayed differential clock pulses;
a NAND gate coupled to the respective series of inverters, said NAND gate comprising complementary sets of transistors controlled by the delayed differential clock pulses to generate the down-pulse; and
a NOR gate coupled to the respective series of inverters, said NOR gate comprising complementary sets of transistors controlled by the delayed differential clock pulses to generate the up-pulse,
wherein undelayed differential clock pulses are provided to the NAND gate, and
wherein delayed differential clock pulses are provided to the NOR gate.
2. A circuit generating an up-pulse and a down-pulse, as recited in claim 1 , wherein the NAND gate comprises:
first and second transistors arranged in parallel between a first reference voltage and an output node, the first and second transistors being of a first type; and
third and fourth transistors arranged in series between the output node and a second reference voltage, the third and fourth transistors being of a second type,
the first and third transistors being controlled by a first differential clock pulse, and
the second and fourth transistors being controlled by a second differential clock pulse.
3. A circuit generating an up-pulse and a down pulse, as recited in claim 2 , wherein the first reference voltage is a source voltage and the second reference voltage is ground.
4. A circuit generating an up-pulse and a down pulse, as recited in claim 1 , further comprising:
a first transistor connected between a first reference voltage and an output node; and
a second transistor connected between a second reference voltage and the output node,
wherein the output of the NAND gate turns the first transistor on and off; and
wherein the output of the NOR gate turns the second transistor on and off.
5. A circuit generating an up-pulse and a down pulse, as recited in claim 4 , wherein the first reference voltage is a source voltage and the second reference voltage is ground.
6. A circuit generating an up-pulse and a down pulse, comprising:
respective series of inverters comprising complementary transistors generating delayed differential clock pulses;
a NAND gate coupled to the respective series of inverters, said NAND) gate comprising complementary sets of transistors controlled by the delayed differential clock pulses to generate the down-pulse; and
a NOR gate coupled to the respective series of inverters, said NOR gate comprising complementary sets of transistors controlled by the delayed differential clock pulses to generate the up-pulse,
wherein delayed differential clock pulses are provided to the NAND gate, and
wherein undelayed differential clock pulses are provided to the NOR gate.
7. A circuit generating an up-pulse and a down-pulse, as recited in claim 6 , wherein the NAND gate comprises:
first and second transistors arranged in parallel between a first reference voltage and an output node, the first and second transistors being of a first type; and
third and fourth transistors arranged in series between the output node and a second reference voltage, the third and fourth transistors being of a second type,
the first and third transistors being controlled by a first differential clock pulse, and
the second and fourth transistors being controlled by a second differential clock pulse.
8. A circuit generating an up-pulse and a down pulse, as recited in claim 7 , wherein the first reference voltage is a source voltage and the second reference voltage is ground.
9. A circuit generating an up-pulse and a down pulse, as recited in claim 6 , further comprising:
a first transistor connected between a first reference voltage and an output node; and
a second transistor connected between a second reference voltage and the output node.
wherein the output of the NAND gate turns the first transistor an and off; and
wherein the output of the NOR gate turns the second transistor on and off.
10. A circuit generating an up-pulse and a down pulse, as recited in claim 9 , wherein the first reference voltage is a source voltage and the second reference voltage is ground.
11. A circuit for generating an up-pulse and a down-pulse, comprising:
a clock circuit for generating first and second clock pulses, the first and second clock pulses being substantially the same in shape but displaced in time from each other by a first delay time;
a first inverter circuit for receiving the first clock pulse and generating a third clock pulse, wherein the third clock pulse is inverted and delayed by a second delay time with respect to the first clock pulse;
a second inverter circuit for receiving the second clock pulse and generating a fourth clock pulse, wherein the fourth clock pulse is inverted and delayed by a third delay time with respect to the second clock pulse;
a NOR gate for performing a NOR operation on the first and third clock pulses to generate the up-pulse; and
a NAND gate for performing a NAND operation on the second and fourth clock pulses to generate the down-pulse.
12. A circuit for generating an up-pulse and a down-pulse, as recited in claim 11 , further comprising:
a first transistor connected between a first reference voltage and an output node; and
a second transistor connected between a second reference voltage and the output node,
wherein an output of the NAND gate turns the first transistor on and off; and
wherein an output of the NOR gate turns the second transistor on and off.
13. A circuit generating an up-pulse and a down pulse, as recited in claim 12 , wherein the first reference voltage is a source voltage and the second reference voltage is ground.
14. A circuit generating an up-pulse and a down pulse, as recited in claim 11 , wherein the first clock pulse is delayed by the first delay time with respect to the second clock pulse.
15. A circuit generating an up-pulse and a down pulse, as recited in claim 11 , wherein the second clock pulse is delayed by the first delay time with respect to the first clock pulse.
16. A circuit generating an up-pulse and a down pulse, as recited in claim 11 , wherein the clock circuit comprises:
a clock generator for generating the first clock pulse;
an delay element for delaying the first clock pulse by the first delay time to generate the second clock pulse.
17. A circuit generating an up-pulse and a down pulse, as recited in claim 11 , wherein the clock circuit comprises:
a clock generator for generating the second clock pulse;
an delay element for delaying the second clock pulse by the first delay time to generate the first clock pulse.
18. A circuit generating an up-pulse and a down pulse, as recited in claim 11 , wherein the first, second, and third delay times are substantially equal.
19. A circuit generating an up-pulse and a down pulse, as recited in claim 11 , wherein the first inverter circuit comprises an odd number of inverter elements.
20. A circuit generating an up-pulse and a down pulse, as recited in claim 11 , wherein the second inverter circuit comprises an odd number of inverter elements.