Why DDR termination voltage is half the supply voltage

[hioyo]

May I know why DDR termination voltage is kept half of the supply voltage.

 

[barry]

because that’s the middle of range of the signal voltage swing.

 

[hioyo]

Does it have any relation to the power dissipation in the termination resistor.Below statement is taken from an
application note.
"
the
termination resistor is connected to a supply voltage
(VTT) that is one-half the VDD voltage. The dissipation in
the termination resistor is then constant regardless of the
supply voltage and is equal to VTT [or (VDD/2)] squared
divided by the termination resistance.
"

--- Updated Jan 22, 2023 ---

"because that’s the middle of range of the signal voltage swing." May I know what is the advantage of this

 

[barry]

Yes, reduces power and also improves signal integrity

 

[careymariah]

May I know why DDR termination voltage is kept half of the supply voltage.

Using a termination voltage that is half the supply voltage is an important design choice for DDR memory that helps ensure signal integrity and minimize power consumption.