DDR_VREF to 1.55V

Thibault B.

Hi !

I am designing a custom board with a DM365. I am trying to reduce the power consumption of the board, that's why I found an interesting DDR2-SDRAM: MT47R64M16. The power supply of this DDR2 is around Vddq = 1.55V. So, will the interface between the RAM and the DM365 work with a Vddq/2=0.775 power supply to the DDR_VREF pin?

Regards,

Thibault

over 15 years ago

0 Miguel A. Alanis over 15 years ago

TI__Genius 9490 points

Thibault,

The power supply for the DDR interface is 1.8V and the range of this supply is +/- 5% ONLY: min can be 1.71V and the max can be 1.89V: as stated in the datasheet device operating conditions section 5.2. The DDR_VREF needs to be 0.5 * VDD18_DDR = 0.9V for SSTL2 specific reference voltage (stated in the datasheet under the pin in table 2-5)

Here's a helpful wiki on some guidelines for reducing power consumption on the I/Os (particularly on the 3.3V I/Os) Hope this helps. http://processors.wiki.ti.com/index.php/General_Guidelines_for_Reducing_I/O_Power_Consumption

regards,

miguel