The Infineon CY7C1021BN-15ZSXET is a 1Mbit asynchronous SRAM organized as 64K x 16 bits, a workhorse memory part for legacy industrial, telecom, and embedded systems that need fast, simple parallel memory without refresh overhead. Its 15 ns access time supports 16-bit microcontrollers and DSPs.
For a 40 MHz bus (25 ns cycle), that leaves about 10 ns of margin for address decode, PCB trace delay, and setup time at the processor — tight but workable with careful layout. At 50 MHz (20 ns cycle) the margin shrinks to near zero, so verify timing closure in your specific system. Write cycle time is also 15 ns, so back-to-back writes can run at the same speed as reads — no penalty for mixed traffic.
For an existing BOM that uses this exact SRAM, the path forward is either last-time-buy inventory from the factory (if still within the LTB window — check with your Infineon contact) or sourcing from the independent surplus and broker channel. We can quote current availability and pricing against an RFQ through our distribution network. If you are qualifying a replacement, the key parameters to match are the 64K x 16 organization, 15 ns access time, 4.5V–5.5V supply, and 44-TSOP II footprint. Several vendors (ISSI, Alliance Memory, Renesas) offer pin-compatible 1Mbit async SRAMs in the same package — but always verify the pinout and timing against your specific layout.
Package and handling in the field
The CY7C1021BN-15ZSXET comes in a 44-TSOP II (10.16 mm body width) surface-mount package, supplied in Tape & Reel.