Alliance Memory AS4C SDRAM

Alliance Memory AS4C SDRAM is high-speed CMOS synchronous DRAM containing 64Mbits, 128Mbits, or 256Mbits. They are internally configured as 4 banks of 1M, 2M, or 4M word x 16 DRAM with a synchronous interface (all signals are registered on the positive edge of the clock signal, CLK). Read and write accesses to the SDRAM are burst oriented, accesses start at a selected location and continue for a programmed number of locations in a programmed sequence. Accesses begin with the registration of a BankActivate command, which is then followed by a Read or Write command.

Alliance Memory AS4C Series SDRAM provides for programmable Read or Write burst length of 1, 2, 4, 8, or full page, with a burst termination option. An auto precharge function is enabled to provide a self-timed row precharge initiated at the end of the burst sequence. The refresh functions, either Auto-Refresh or Self-Refresh, are easy to use. By having a programmable mode register, the system can choose the most suitable modes to maximize its performance.

These devices are ideal for applications requiring high memory bandwidth as well as high-performance PC applications.


  • Low power consumption of +1.2V (±0.06V) 
  • Offered in 96-ball and 78-ball FBGA packages 
  • Internally configured
    • 8 banks x 256Mb x 16 bit
    • 16 banks x 512Mb x 8 bit
  • Fast clock speeds of 1200MHz and 1333MHz 
  • Support sequential and interleave burst types with read or write burst lengths of BL8/BC4/BC4 or 8 on the fly
  • 2400Mbps/pin and 2666Mbps/pin extremely high transfer rates
  • Extended commercial (0°C to +95°C) and industrial (-40°C to +95°C) temperature ranges  
  • 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 
  • JEDEC- and RoHS-compliant 
  • Lead (Pb)- and halogen-free


  • Portable electronics
  • Desktop computers
  • Servers for industrial
  • Medical
  • IoT
  • Automotive
  • Gaming
  • Consumer
Publicado: 2011-11-10 | Actualizado: 2022-03-11