1998-12-15 , S/IC-2050/24
Product News From Philips Semiconductors

DDR memory interface products support high-end applications

Philips Semiconductors today announced three new products which support Double Data Rate (DDR) SDRAM Memory Modules. The first of the DDR support circuits are currently being sampled by memory module engineers, with volume production expected to begin in late Q1, 1999.

DDR is a Joint Electronic Device Engineering Council (JEDEC) committee standard supported by major SDRAM manufacturers. DDR SDRAMS are differentially clocked and include an on-chip DLL and SSTL_2 interface that permit a peak bus bandwidth of more than double that available on 100 MHz SDRAMS. A DDR SDRAM clocked at 100 or 133 MHz will have a burst rate of 200 or 266 MHz, which equates to a peak bandwidth of greater than 2.1 GB/S in an eight-byte application. Higher burst rates are needed to support the demands of higher speed core processors used in both PC systems and high-speed server applications.

"Philips Semiconductors is the first supplier to provide IBM with components supporting the evolutionary JEDEC DDR standard", said Mark Kellogg, lead engineer for memory subsystems at IBM Microelectronics Division. "Philips Semiconductors' DDR circuits enable IBM memory modules to respond to the industry's need."

A typical DDR memory module requires between 23 and 27 registered control and address lines, so two 14-bit  SSTL 16857's are required on each memory module card. The SSTL 16857 is a 14-bit SSTL_2 registered driver with differential clocks and is available in a 48-pin TSSOP package. In order to synchronize signals on the individual memory chips, a  PCK857 PLL is also required on each memory module. The PCK857 is a 150 MHz differential 1:10 SDRAM clock driver in a 48-pin TSSOP package. Optional  CBT3857 FET switches may be installed between DQ lines and the edge connector to disconnect the DQ nets on unselected DIMM's from the system bus. This reduces line reflections from unselected DIMMS. The CBT3857 is a 10-bit bus switch with 10k ohm pull down termination resistors available in a 24-pin TSSOP package.

"Memory module suppliers such as IBM see the advantages of Philips Semiconductors' DDR products, including high performance, optimized cost and an integrated approach toward support of the DDR standard," said Pierre-Yves Lesaicherre, international product marketing manager for the PC Motherboard Product organization within Philips Semiconductors' Logic Products group. "Philip's DDR memory module products enhance the product portfolio by offering a full spectrum of products which support a wide range of motherboard applications from lower end PCs to high-end servers."

In addition to the DDR standard, Philips Semiconductors' offers DIMM vendors memory interfaces for industry standard SDRAM technologies such as PC100 and PC133. Philips Semiconductors' ICs include high-performance registers, buffers, Phase Locked Loops (PLLs), and Cross Bar Technology (CBT) Field Emitting Transistor (FET) switches.

Building on its expertise as a supplier of high-volume logic products to the PC market, Philips Semiconductors recently launched the PC Motherboard Products line within the Logic Products group. An extensive array of products target four critical motherboard areas: clock generators and drivers, processors and chipset interfaces, memory interfaces, and system management ICs. "Philips Semiconductors provides a complete solution to PC motherboard designers in the four targeted areas," said Lesaicherre. "In this new PC motherboard arena, our products provide high technical and innovative content with the widely-recognized Philips Semiconductors' quality." Additional information on Philips Semiconductors' PC motherboard products can be found at  www.semiconductors.philips.com/logic.

Philips Semiconductors, a division of Royal Philips Electronics, headquartered in Eindhoven, The Netherlands, is the ninth largest semiconductor supplier in the world and the third largest supplier of discretes in the world. Philips Semiconductors' innovations in digital audio, video, and mobile technology position the company as a leader in the consumer, multimedia and wireless communications markets. Sales offices are located in all major markets around the world and are supported by systems labs.