The Mitsubishi M5M5W816WG-55HI#BT is a standard SRAM with 512Kx16 organization and a 55 ns access time. This is the timing parameter that governs read and write cycle compatibility with your processor or FPGA memory controller. A 55 ns access time means the data is valid on the bus within 55 ns of the address being stable — critical for meeting setup and hold times on a 16-bit data bus running at moderate clock rates. For a typical 8 MHz to 12 MHz microcontroller or a medium-speed DSP, this part fits without wait-state insertion. The 512K-word depth (8 Mbit total) provides 1 MB of byte-addressable storage, sized for boot code, lookup tables, or frame buffers in embedded systems.
This is a straightforward fit for production BOMs and new designs that need a reliable parallel SRAM source. No need to qualify a substitute or stockpile ahead of a phase-out window.
Peer variant — M5M5W816WG-70HI#BT
The same Mitsubishi SRAM family includes the M5M5W816WG-70HI#BT, which differs only in access time: 70 ns versus the 55 ns of this part. For systems that can tolerate the slower access, the 70 ns variant offers a cost-reduction path or a second-source option without changing footprint or pinout. The 55 ns part gives tighter timing margin on a faster bus, while the 70 ns version may be adequate for slower controllers or when derating for temperature is less critical.