Serial SRAM portfolio expanded to larger densities and increased speeds

To manage a common customer demand for bigger and faster SRAM, Microchip Technology has expanded its Serial SRAM product line to include larger densities of up to 4Mb and increased SPI/SQI speed to 143MHz. The 2Mb and 4Mb devices are created to deliver a lower-cost alternative to traditional parallel SRAM products and include optional battery backup switchover circuitry in the SRAM memory to retain data on power loss.

Unlike parallel RAM, which needs large packages and at least 26-35 MCU I/Os to interface, the company's serial SRAM devices come in a lower-cost, eight-pin package and use a high-speed SPI/SQI communication bus that only needs 4−6 MCU I/O pins for easy integration. This decreases the necessity for a more expensive, high-pin-count MCU and can help minimise the overall board footprint.

Addressing the most common drawback to serial SRAM – that parallel is faster than serial memory – the 2Mb and 4Mb serial SRAM devices have increased the bus speed capability to 143MHz with optional quad SPI (4 bits per clock cycle), which greatly minimises the speed gap between solutions.

"Serial SRAM is a popular solution for engineers who need more RAM than what is available on board their MCU but are looking to reduce cost and overall board size," said Jeff Leasure, director of Microchip's memory products business unit. "Microchip's 2Mb and 4Mb serial SRAM devices are intended to replace expensive parallel SRAM with an easy and cost-effective alternative."

The small-form-factor, low-power, high-performance serial SRAM devices have unlimited endurance and zero write times, making them excellent options for applications involving continuous data transfer, buffering, data logging, metering and other math- and data-intensive functions. These devices are available in 64Kbit up to 4Mb density and support SPI, SDI and SQI bus modes.