SEOUL -- Samsung Electronics Co. Ltd. today announced it is sampling a multi-chip package device that stacks a 64-megabit NAND-type flash memory chip and an 8-Mbit SRAM together for use in third-generation (3G) cellular phones.
Wireless handsets currently have 16-Mbit or 32-Mbit NOR-type flash memory built-in, but the wireless Internet access capabilities of 3G phones necessitates an increased flash memory capacity to store music files, still picture data and other applications, according to Samsung.
The SRAM serves as a buffer/working memory, while the NAND flash chip stores data. Samsung's new device will be 8-mm wide, 13-mm long and 1.2-mm thick and is packaged in a 69-signal ball grid array (BGA) with a 0.8-mm pitch between contacts. The NAND flash shares I/O's and other control pins with the SRAM, minimizing additional pins. The pin-out accommodates future memory expansion of SRAM to 64 Mbits and NAND-type flash memory to 512 Mbits, the company said.
The device will be set to operate at between 2.4 and 3.0 volts for both the SRAM and flash memory. For interfacing with chips sets operated at lower power, a scaleable I/O interface is also provided. The low-power 8-Mbit SRAM is designed with 0.18-micron technology providing an access time of 85 nanoseconds, while a 0.22-micron design rule is applied to the 64-Mbit NAND-type flash memory.