What this 4Mbit asynchronous SRAM brings to the bus
The Infineon CY62148EV30LL-55SXI is a 4Mbit (512K x 8) asynchronous SRAM from the MoBL® series, built for low-power standby in battery-backed and industrial designs. Its 55 ns access time sets the read-cycle floor — a 18 MHz bus can grab a word every cycle without wait states, but a 40 MHz MCU will need one wait inserted. The wide 2.2V to 3.6V supply range lets it sit on a 3.3V rail directly, no level translation on the address or data lines.
55 ns access — budget it against your processor clock
At 55 ns, this part is in the middle-speed tier for 4Mbit asynchronous SRAM. A 20 MHz bus cycle is 50 ns, so a back-to-back read requires one wait state. For a 16 MHz microcontroller the access fits within a single 62.5 ns cycle, yielding zero-wait performance. If your processor runs at 40 MHz or above, consider a 10 ns part like the CY7C1049GN30-10VXI — though that trades standby current for speed.
Package and footprint — the 32-SOIC wide body
The 32-SOIC package (0.445-inch body width, 11.30 mm) is a standard JEDEC outline for 512Kx8 asynchronous SRAM. Surface-mount assembly with standard reflow profile;
3.3V logic compatibility — no level shifters needed
With a supply range of 2.2V to 3.6V, this SRAM operates directly from a 3.3V rail. All inputs and I/O are 3.3V-tolerant at that supply, so an MCU or FPGA with 3.3V CMOS outputs connects straight to the address and data bus without external level translators. The part also runs at 2.5V or 2.2V for battery-backed operation, though access time may stretch slightly at the low end of the range.