LONDON -- Fujitsu Ltd.'s European chip operation today claimed to be offering the industry's first triple-stacked multi-chip package (MCP) for cellular phones, combining three types of memories for digital handsets.
The multi-chip package combines a 64-megabit NOR-type flash memory, a 16-Mbit mobile fast-cycle random access memory (FCRAM) with an asynchronous SRAM interface, and a 4-Mbit SRAM.
Fujitsu said the triple-stacked MCP format addresses new demands in cell-phone handsets by packaging together flash for program and data storage, high data-capacity FCRAM as "working memory," and SRAM as cache memory for backup storage when downloading data or when systems are in standby mode.
With cell-phone functions expanding to cover Internet access, downloading of Java applets, and Web browsing, the need for more memory and higher speeds is growing in handsets, said the company. The multi-chip package reduces power used by combining memory chips and minimizing part counts as well as interconnect wiring.
The 85-ball plastic ball grid array (PBGA) package measures 10.4-by-10.8-by-1.3mm. The height of the package is slightly slimmer than conventional MCPs, according to Fujitsu. By combining three chips into one package, the MCP uses 30% less board area than previous devices, said the company.
The new MB84VR5E3J1A1 offers an address access/program (one word) cycle time of 85 ns (maximum), a standard NOR-type flash memory access time of 80 ns, a mobile FCRAMrandom read access time of 90 ns (max) and an SRAM read access time of 85 ns (max).
Fujitsu Microelectronics Europe said the MCP operates from a power supply of 2.7 to 3.1 volts. In standby mode the flash memory has a maximum consumption of 5 microamps, the FCRAM 70 microamps and the SRAM 7 microamps. In power-saving mode the FCRAM consumes 10 microamps.
The MB84VR5E3J1A is now available in sample quantities with volume production commencing in September. Pricing was not released