STMicroelectronics announces termination network that paves the way to space-saving shortcut for double data rate DIMMs
STMicroelectronics today announced a chip-level 10-resistor network, the DDR110-xxT7, that eases the work of designers who want to take advantage of the latest 266-MHz double data-rate (DDR) synchronous DRAMs mounted on dual in-line memory modules (DIMMs). DDR DIMMs use series stub terminated logic (SSTL), which requires a parallel termination resistor on each line.
Besides saving sparse motherboard space by eliminating termination cards, the DDR110xxT7 automatically disconnects its termination resistors when rocketing slower single data-rate (SDR) DIMMs. In this way, the new chip simplifies high-volume motherboard layout and production. The DDR110-xxT7 will find use in high-performance desktop and notebook personal computers, workstations, and servers having processor clock rates of 1 GHz and above.
Specifically, the DDR110-xxT7 works with PC 100, PC 133, PC 1600, and PC2100 DIMMs, and serves as a companion device for the Aladdin Pro 5 and ALiMAGiKl system chip sets from ACER Labs Inc., the SIS635(T) and SIS735 from Silicon Integrated Systems Corp., and the Apollo PR0266 and Apollo KT266 from VIA Technologies Inc.
To accommodate both DDR and SDR DIMMs, each of the DDR110-xxT7's 10 termination resistors includes a switch. The switches are controlled in unison by the chip's TTL-compatible Output Enable (OE) signal line, which connects the resistors from input to output - typically a 1.25V termination voltage - when set high, and disconnects them, leaving an open circuit, when low.
The DDR110-xxT7 chip is designed for easy board layout, low crosstalk and improved signal integrity. Built using ST's IPAD (Integrated Passive and Active Device) process, the DDR110-xxT7 expands the company's line of reliable, space saving, and high performance devices, including EMI filters and ESD protection devices, which benefit from IPAD technology.
The DDR110-xxT7 is available with termination resistor values of 27 Ohm, and 56 Ohm. The chip comes in a 24-pin TSSOP having a 0.65-mm pin pitch and is available on tape and reel. Units are available now for $.35 in 500k volume quantities.
About STMicroelectronics
STMicroelectronics is the world's third largest independent semiconductor company. The Company shares are traded on the New York Stock Exchange, on Euronext Paris and on the Milan Stock Exchange. The Company designs, develops, manufactures and markets a broad range of semiconductor integrated circuits (ICs) and discrete devices used in a wide variety of microelectronic applications, including telecommunications systems, computer systems, consumer products, automotive products and industrial automation and control systems. In 2000, the Company's net revenues were $7,813.2 million and net earnings were $1,452.1 million.
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