SPI Serial SRAM and NVSRAM Devices

By Microchip Technology 255

SPI Serial SRAM and NVSRAM Devices

Microchip's serial SRAM family provides a way to easily and inexpensively add external RAM to almost any application. These 8-pin serial devices use less power and fewer I/O connections than traditional parallel SRAM. They also allow designers to use a smaller microcontroller rather than moving to a larger device just to get more on-board RAM. Zero write-cycle times make these devices ideal for offloading graphics, data buffering, data logging, displays, math, audio, video, and other data-intensive functions to a standalone SRAM. SDI and SQI allow for 2x and 4x data rates compared with standard SPI. SPI-compatible serial SRAM devices from Microchip are available in 64 Kbit, 256 Kbit, 512 Kbit, and 1024 Kbit options. These devices provide high-speed performance at low power making them ideal for embedded applications needing more RAM.

Additionally, the 512 Kb and 1 Mb devices also feature a VBAT pin for battery backup, making them non-volatile when an external battery or supercap is connected to this pin. These serial NVSRAM devices offer unlimited endurance and instantaneous writes and are beneficial for applications such as meters, black boxes, and data recorders.

  • Low-power CMOS technology: 4 μA max standby current
  • Standard 4-pin SPI interface: chip select, data in, data out, and clock
  • Unlimited writes to memory, zero write times
  • Battery backup available (512 Kb, 1 Mb)
  • 32-byte page
  • High-speed SDI (2x) and SQI (4x) modes supported, up to 80 Mb / sec
  • Industrial temperatures range: -40°C to +85°C
  • Small, 8-lead SOIC, TSSOP, and PDIP packages