What this 4Mbit async SRAM brings to the board
The R1RW0416DSB-0PI#D0 is a Renesas 4Mbit asynchronous SRAM organized as 256K x 16 bits. Its 10 ns access time means the memory controller can read or write a word within a single 100 MHz clock cycle — useful for cache, frame buffers, or parameter tables in DSP and MCU systems. The parallel interface and 3V–3.6V supply make it a drop-in fit for 3.3V logic families; no level shifters needed on the data bus.
Housed in a 44-TSOP II (0.400" body width, 10.16 mm), the surface-mount package is compatible with standard reflow profiles. The 0.50 mm pin pitch demands a controlled impedance PCB stack if the bus runs above 50 MHz, but for most asynchronous designs a two-layer board with proper decoupling is sufficient.
That means the BOM line is safe for new production runs and there is no urgency to stockpile or qualify a second source. Delivery is Bulk, typically in trays or tubes. Confirm the exact tray quantity with your distributor at quote time; the count varies by manufacturing lot.