samyakgandhi
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following are some analysis i made:
1)pure open drain configuration is capable of achieving low power by eliminating current flow while in logic 1 state, but at the same time it suffers reduction in speed of operation compared to push/pull configuration which is capable of driving both the ways.
2)to overcome the speed issue a weak pull up is added in the driver, while still incorporating the low power advantage by eliminating the vdd/2 termination as in push/pull config. such type of technology is termed as pseudo open drain technology(POD) and is used in ddr4 drivers.
3)now ddr4(POD cfg) operates at higher frequency than ddr3(push/pull cfg), so the amount of current to be pumped or drawn by the driver should be more to charge and discharge the load faster.
4)but the weak pull up in the POD cfg. will limit the amount of current.
so i am not able to figure how ddr4 is able to achieve higher speed with POD cfg. than ddr3 with pushpull cfg. ?
thanks,
waiting for a reply
1)pure open drain configuration is capable of achieving low power by eliminating current flow while in logic 1 state, but at the same time it suffers reduction in speed of operation compared to push/pull configuration which is capable of driving both the ways.
2)to overcome the speed issue a weak pull up is added in the driver, while still incorporating the low power advantage by eliminating the vdd/2 termination as in push/pull config. such type of technology is termed as pseudo open drain technology(POD) and is used in ddr4 drivers.
3)now ddr4(POD cfg) operates at higher frequency than ddr3(push/pull cfg), so the amount of current to be pumped or drawn by the driver should be more to charge and discharge the load faster.
4)but the weak pull up in the POD cfg. will limit the amount of current.
so i am not able to figure how ddr4 is able to achieve higher speed with POD cfg. than ddr3 with pushpull cfg. ?
thanks,
waiting for a reply
