Semiconductor integrated circuit and receiving device
A semiconductor integrated circuit includes a first circuit and a second circuit. The first circuit is configured to divide a first pulse signal having a first duty cycle by N (where N is an integer of 2 or more), and output 2×N second pulse signals of which phases are different from each other. The first pulse signal is a pair of differential signals. The second circuit is configured to receive one or more selection signals and calculate a logical product of one of the one or more selection signals and two of the 2×N second pulse signals to generate a third pulse signal having a second duty cycle less than the first duty cycle.
1. A semiconductor integrated circuit, comprising:
a first circuit configured to divide a first pulse signal having a first duty cycle by N (where N is an integer of 2 or more), the first pulse signal being a pair of differential signals, and output 2×N second pulse signals with phases which are different from each other; and
a second circuit configured to receive one or more selection signals and calculate a logical product of one of the one or more selection signals and two of the 2×N second pulse signals to generate a third pulse signal having a second duty cycle less than the first duty cycle.
2. The semiconductor integrated circuit according to claim 1 , wherein phases of the 2×N second pulse signals are equally separated by 180/N degrees.
3. The semiconductor integrated circuit according to claim 1 , wherein
the second circuit includes a plurality of AND circuits, each of the AND circuits having three input terminals that receive one of the one or more selection signals and two of the 2×N second pulse signals, and
a combination of the two of the 2×N second pulse signals is different from each other among the plurality of AND circuits.
4. The semiconductor integrated circuit according to claim 1 , wherein
the one or more selection signals comprise N selection signals,
the second circuit includes a plurality of AND circuits, each of the AND circuits having three input terminals that receive one of the N selection signals and two of the 2×N second pulse signals, and
a combination of the one of the N signals and the two of the 2×N second pulse signals is different from each other among the plurality of AND circuits.
5. The semiconductor integrated circuit according to claim 4 , wherein the number of the plurality of AND circuits is 8×N.
6. The semiconductor integrated circuit according to claim 1 , wherein the first duty cycle is 50%.
7. The semiconductor integrated circuit according to claim 6 , wherein the second duty cycle is one of 12.5%, 25%, and 37.5%.
8. The semiconductor integrated circuit according to claim 1 , wherein the second circuit includes a delay circuit, and the two of the 2×N second pulse signals from which the third pulse signal is generated comprise a fourth pulse signal that is not delayed by the delay circuit and a fifth pulse signal that is delayed by the delay circuit.
9. The semiconductor integrated circuit according to claim 8 , wherein a delay caused by the delay circuit corresponds to a duty cycle of less than 50%.
10. The semiconductor integrated circuit according to claim 1 , wherein the third pulse signal is a clock signal.
11. A receiving device, comprising:
an equalizing circuit configured to receive an analog signal and output a compensated analog signal;
a clock circuit including:
a first circuit configured to divide a first clock signal having a first duty cycle by N (where N is an integer of 2 or more), the first clock signal being a pair of differential signals, and output 2×N second clock signals with phases which are different from each other; and
a second circuit configured to receive one or more selection signals and calculate a logical product of one of the one or more selection signals and two of the 2×N second clock signals to generate a third clock signal having a second duty cycle less than the first duty cycle; and
a conversion circuit configured to perform analog-to-digital conversion of the compensated analog signal using the third clock signal.
12. The receiving device according to claim 11 , wherein phases of the 2×N second clock signals are equally separated by 180/N degrees.
13. The receiving device according to claim 11 , wherein
the second circuit includes a plurality of AND circuits, each of the AND circuits having three input terminals that receive one of the one or more selection signals and two of the 2×N second clock signals, and
a combination of the two of the 2×N second clock signals is different from each other among the plurality of AND circuits.
14. The receiving device according to claim 11 , wherein
the one or more selection signals comprise N selection signals,
the second circuit includes a plurality of AND circuits, each of the AND circuits having three input terminals that receive one of the N selection signals and two of the 2×N second clock signals, and
a combination of the one of the N signals and the two of the 2×N second clock signals is different from each other among the plurality of AND circuits.
15. The receiving device according to claim 14 , wherein the number of the plurality of AND circuits is 8×N.
16. The receiving device according to claim 11 , wherein the first duty cycle is 50%.
17. The receiving device according to claim 16 , wherein the second duty cycle is one of 12.5%, 25%, and 37.5%.
18. The receiving device according to claim 11 , wherein the second circuit includes a delay circuit, and the two of the 2×N second clock signals from which the third clock signal is generated comprise a fourth clock signal that is not delayed by the delay circuit and a fifth clock signal that is delayed by the delay circuit.
19. The receiving device according to claim 18 , wherein a delay caused by the delay circuit corresponds to a duty cycle of equal to or less than 50/N %.
20. The receiving device according to claim 11 , wherein the analog-to-digital conversion performed by the conversion circuit includes a time-interleaved analog-to-digital conversion.