20 ns asynchronous SRAM — what the access time means for bus timing
The CY7C1009B-20VC is a 1Mbit asynchronous SRAM from Cypress, organized as 128K x 8, with a 20 ns access time. In a 5V system running at 25 MHz or slower, this part keeps the read cycle within one clock period without wait states. The parallel interface and 20 ns write cycle time match legacy DSPs, 8-bit microcontrollers, and CPLD-based glue logic that expect fast, simple memory handshaking.
5V-only supply — a common mis-spec trap
This is a 5V-only part — it will not operate at 3.3V. For industrial or automotive use, a wider-temperature SRAM (e.g., -40°C to 85°C) in a similar density and package would be required.
Cypress lists the CY7C1009B-20VC as Obsolete. Production has ended; the only available inventory is new-old-stock or surplus held by independent distributors. If you are qualifying a replacement for a production BOM, expect to evaluate pin-compatible SRAMs from other vendors in the same 32-SOJ footprint and 5V supply class.
32-SOJ package — footprint and handling
It is a surface-mount package with J-bend leads on 1.27 mm pitch. The supplier device package is 32-SOJ. The listed shipping medium is Tube.