The device provides a reliable, pin-compatible drop-in replacement for a number of similar products available today.
The AS4C128M16D2 DDR2 DRAM is organised as eight banks of 16 x 16Mbits. It achieves high data-transfer rates by employing a chip architecture which pre-fetches multiple bits and then synchronises the output data to a system clock.
The chip is designed to meet key DDR2 SDRAM requirements:
• Posted Column Access Strobe (CAS) with additive latency
• Write latency = Read latency-1
• On-Die Termination (ODT)
All of the control and address circuits are synchronised with the positive edge of an externally supplied clock. I/Os are synchronised with a pair of bi-directional strobes in a source-synchronous fashion.
Operating the eight memory banks in an interleaved fashion allows random access operation to occur at a higher rate than is possible with standard DRAMs. A sequential and gapless data rate is possible depending on burst length, CAS latency and the speed grade of the device.
All variants are available in commercial, 0°C to 85°C, and industrial, -40°C to 95°C, temperature ranges. An automotive temperature range of -40°C to 105°C is available on some parts. The functionally equivalent AS4C128M16D2A, fabricated in a different location from the AS4C128M16D2, is also available to give customers confidence in the parts’ continuity of supply.
- Single 1.8V power supply
- 400MHz clock rate
- 800Mbits/s data rate per pin
- Programmable Read or Write burst lengths of 4 or 8
- Easy-to-use Refresh functions
- Programmable mode and extended mode registers
- Automotive systems
- Industrial equipment
- Consumer devices
- Networking equipment
- Medical products
- Embedded systems