A 10 Gbits/s/pin DFE-Less Graphics DRAM Interface With Adaptive-Bandwidth PLL for Avoiding Noise Interference and CIJ Reduction Technique

Abstract

A 10 Gbits/s/pin graphics DRAM interface is developed in 65-nm CMOS technology. Several design techniques are proposed for high-speed operation in a noisy environment. A fast precharging data sampler guarantees high-speed sampling without the need for a decision feedback equalizer. In order to increase the data sampling margin, the PLL bandwidth is optimized depending on the system noises, which reduces the clock jitter by up to 55.1%. The crosstalk-induced jitter (CIJ) reduction technique suppresses the DQs jitter by employing the suggested training sequence for the GDDR5 interface. Pre- and de-emphasis are merged in one auxiliary driver. This chip operates at 10 Gbits/s/pin and exhibits a data eye opening of 0.78 UI with the CIJ reduction technique. The power consumptions of the TX and RX are 8.28 and 5.5 pJ/b/channel, respectively.