A line of high-speed CMOS DDR SDRAMs with densities of 64Mb, 128Mb, 256Mb and 512Mb has been announced by Alliance Memory. The 64Mb (AS4C4M16D1-5TIN), 128Mb (AS4C8M16D1-5TIN), 256Mb (AS4C16M16D1-5TIN), and 512Mb (AS4C32M16D1-5TIN) devices havew an industrial temperature range of -40°C to +85°C.
The devices released today provide reliable drop-in, pin-for-pin-compatible replacements for a number of similar solutions in industrial, medical, communications, and telecom products requiring high memory bandwidth, and they are particularly well-suited to high performance in PC applications. Internally configured as four banks of 1M, 2M, 4M, or 8M word x 16 bits with a synchronous interface, the DDR SDRAMs operate from a single +2.5-V (± 0.2 V) power supply and are lead (Pb)- and halogen-free.
The AS4C4M16D1-5TIN, AS4C8M16D1-5TIN, AS4C16M16D1-5TIN, and AS4C32M16D1-5TIN feature a fast clock rate of 200 MHz and are offered in the 66-pin TSOP II package with a 0.65-mm pin pitch. The 128M, 256 Mb and 512 Mb devices are also available in a TFBGA package. The DDR SDRAMs provide programmable read or write burst lengths of 2, 4, or 8. An auto pre-charge function provides a self-timed row pre-charge initiated at the end of the burst sequence. Easy-to-use refresh functions include auto- or self-refresh while a programmable mode register allows the system to choose the most suitable modes to maximize performance.