Method and system using driver equalization in transmission line channels with power or ground terminations
View Patent ↗A driver circuit device using driver equalization in power and ground terminated transmission line channels. The driver circuit device can include a weaker pull-up driver, which is needed to pre-emphasize the pull-up signal for driver equalization in power terminated transmission line channels. The driver circuit device can also include a weaker pull-down driver, which is needed to pre-emphasize the pull-down signal for driver equalization in ground terminated transmission line channels. In the transmission line channels with power terminations, a weaker pull-up Ron is implemented. In the transmission line channels with ground terminations, a weaker pull-down Ron is implemented. Drivers implemented in power and/or ground terminated transmission line channels can be used to improve device performance, such as in signal eye opening.
1. A method of driver equalization in a transmission line of a driver circuit device, the method comprising:
providing the driver circuit device, the driver circuit device having a first power-terminated driver module, the first power-terminated driver module including
a first driver having a first driver output,
a first transmission line channel having a first end and a second end, the first end of the first transmission line channel being coupled to the first driver output,
a first receiver having a first receiver input, the second end of the first transmission line channel being coupled to the first receiver input, and
a first power termination coupled to the first receiver input and the second end of the first transmission line channel;
configuring the first driver with a first resistance network module, the first resistance network module being characterized by a weak on-resistance;
receiving, by the first power-terminated driver module, a pull-up signal; and
pre-emphasizing, by the first resistance network module of the first driver, the pull-up signal to strengthen the pull-up signal for driver equalization.
2. The method of claim 1 wherein the first driver module is configured for a pull-up signal from a “0” value to a “1” value.
3. The method of claim 1 wherein the weak on-resistance is characterized by a resistance value greater than or equal to 50Ω.
4. The method of claim 1 wherein the driver circuit device further comprises:
a second power-terminated driver module including
a second driver having a second driver output,
a second transmission line channel having a first end and a second end, the first end of the second transmission line channel being coupled to the second driver output,
a second receiver having a second receiver input, the second end of the second transmission line channel being coupled to the second receiver input, and
a second power termination coupled to the second receiver input and the second end of the second transmission line channel; and further comprising
configuring the second driver with a second resistance network module, the second resistance network module being characterized by a strong on-resistance;
receiving, by the second power-terminated driver module, the pull-up signal; and
deemphasizing, by the second resistance network module of the second driver, the pull-up signal to weaken the pull-up signal for driver equalization.
5. The method of claim 4 wherein the second power-terminated driver module is configured for a pull-up signal of consecutive “1” values.
6. The method of claim 4 wherein the strong on-resistance is characterized by a resistance value ranging between 0Ω to 50Ω.
7. A method of driver equalization in a transmission line of a driver circuit device, the method comprising:
providing the driver circuit device, the driver circuit device having a first ground-terminated driver module, the first ground-terminated driver module including
a first driver having a first driver output,
a first transmission line channel having a first end and a second end, the first end of the first transmission line channel being coupled to the first driver output,
a first receiver having a first receiver input, the second end of the first transmission line channel being coupled to the first receiver input, and
a first ground termination coupled to the first receiver input and the second end of the first transmission line channel;
configuring the first driver with a first resistance network module, the first resistance network module being characterized by a weak on-resistance;
receiving, by the first ground-terminated driver module, a pull-down signal; and
pre-emphasizing, by the first resistance network module of the first driver, the pull-down signal to strengthen the pull-down signal for driver equalization.
8. The method of claim 7 wherein the first ground-terminated driver module is configured for a pull-down signal from a “1” value to a “0” value.
9. The method of claim 7 wherein the weak on-resistance is characterized by a resistance value greater than or equal to 50Ω.
10. The method of claim 1 wherein the driver circuit device further comprises:
a second ground-terminated driver module including
a second driver having a second driver output,
a second transmission line channel having a first end and a second end, the first end of the second transmission line channel being coupled to the second driver output,
a second receiver having a second receiver input, the second end of the second transmission line channel being coupled to the second receiver input, and
a second ground termination coupled to the second receiver input and the second end of the second transmission line channel; and further comprising
configuring the second driver with a second resistance network module, the second resistance network module being characterized by a strong on-resistance;
receiving, by the second ground-terminated driver module, the pull-down signal; and
deemphasizing, by the second resistance network module of the second driver, the pull-down signal to weaken the pull-down signal for driver equalization.
11. The method of claim 10 wherein the second power-terminated driver module is configured for a pull-down signal of consecutive “0” values.
12. The method of claim 10 wherein the strong on-resistance is characterized by a resistance value ranging between 0Ω to 50Ω.
13. A power-terminated driver circuit device, the device comprising:
a first driver coupled to a first end of a first transmission line, the first driver being configured with a first resistance network characterized by a weak on-resistance for a pull-up signal with “0”-to-“1” transition;
a first power termination coupled to a second end of the first transmission line;
a second driver coupled to a first end of a second transmission line, the second driver being configured with a second resistance network characterized by a strong on-resistance for a pull-up signal with consecutive “1”s;
a second power termination coupled to a second end of the second transmission line;
a third driver coupled to a first end of a third transmission line, the third driver being configured with a third resistance network characterized by a strong on-resistance for a pull-down signal with “1”-to-“0” transition;
a third power termination coupled to a second end of the third transmission line;
a fourth driver coupled to a fourth transmission line, the fourth driver being configured with a fourth resistance network characterized by a weak on-resistance for a pull-down signal with consecutive “0”s; and
a fourth power-termination coupled to a second end of the fourth transmission line;
wherein the power-terminated driver circuit device is configured with pull-up de-emphasis and pull-down pre-emphasis for driver equalization.
14. The device of claim 13 wherein each of the weak on-resistances is characterized by a resistance value greater than or equal to 50Ω.
15. The device of claim 13 wherein each of the strong on-resistances is characterized by a resistance value ranging between 0Ω to 50Ω.
16. The device of claim 13 wherein the first and second transmission lines are configured as signal pull-up devices when in energized states.
17. A ground-terminated driver circuit device, the device comprising:
a first driver coupled to a first end of a first transmission line, the first driver being configured with a first resistance network characterized by a strong on-resistance for a pull-up signal with “0”-to-“1” transition;
a first ground termination coupled to a second end of the first transmission line;
a second driver coupled to a first end of a second transmission line, the second driver being configured with a second resistance network characterized by a weak on-resistance for a pull-up signal with consecutive “1”s;
a second ground termination coupled to a second end of the second transmission line;
a third driver coupled to a first end of a third transmission line, the third driver being configured with a third resistance network characterized by a weak on-resistance for a pull-down signal with “1”-to-“0” transition;
a third ground termination coupled to a second end of the third transmission line;
a fourth driver coupled to a fourth transmission line, the fourth driver being configured with a fourth resistance network characterized by a strong on-resistance for a pull-down signal with consecutive “0”s; and
a fourth ground termination coupled to a second end of the fourth transmission line;
wherein the ground-terminated driver circuit device is configured with pull-up pre-emphasis and pull-down de-emphasis for driver equalization.
18. The device of claim 17 wherein each of the weak on-resistances is characterized by a resistance value greater than or equal to 50Ω.
19. The device of claim 17 wherein each of the strong on-resistances is characterized by a resistance value ranging between 0Ω to 50Ω.
20. The device of claim 17 wherein the third and fourth transmission lines are configured as signal pull-down devices when in energized states.