Dynamic random access memory device and μBGA package using multiple reference voltage pads

Abstract

A dynamic random access memory device and a μBGA package for the device use multiple pads for a reference voltage. The device includes n input receivers, n data input pads, and x reference voltage pads. Each input receiver operates synchronously with a clock signal and includes a differential amplifying unit that generates an output data signal according to a voltage difference between an input data signal and a reference voltage. The n data input pads respectively connect to the n input receivers and transfer the input data signals to the input receivers. The n input receivers are divided into x groups according to their positions, and the x reference voltage input pads respectively connect to the x groups of input receivers for commonly applying the reference voltage to the input receivers in the respective groups. Each reference voltage input pad can connect to its group of input receivers through one or multiple common lines. The package includes a first ball that receives the reference voltage. The first ball is commonly connected to the x reference voltage input pads of the device. The average and maximum distances between the reference voltage input pads and input receivers are much shorter with multiple reference voltage pads. Accordingly, the noise level of the reference voltage is smaller, thereby improving a margin in data setup and hold times of the input receivers and the operational reliability of products. Filters connected to the reference voltage pads can further reduce the noise in the reference voltage at the input receivers.

Dependencies are inferred from the claim text.