Last Buy — sourcing reality for this QDR II SRAM
The CY7C1426KV18-300BZCT is classified as Last Buy — the manufacturer has announced end-of-life, and the remaining inventory window is finite. For a BOM line that already carries this part, the procurement decision is to secure the lifetime buy quantity or identify a migration path before supply dries up. This is a 36 Mbit QDR II synchronous SRAM organized as 4M x 9, clocked at 300 MHz with a parallel memory interface. The QDR II architecture delivers two data words per clock cycle — one on the rising edge and one on the falling edge — effectively doubling the data throughput for a given bus clock compared to a single-data-rate SRAM.
300 MHz clock and 36 Mbit density — what they mean for the system
At 300 MHz, the QDR II interface achieves a peak data rate of 600 MHz effective per I/O pin (double data rate). For a 9-bit-wide bus, the aggregate read or write bandwidth is roughly 2.7 Gbit/s — enough to feed a high-performance network processor or FPGA without stalling the pipeline on back-to-back transactions. The 36 Mbit density in a 4M x 9 organization means the part provides 9 bits per address — 8 data bits plus a parity or tag bit. Systems that need wider buses (18 or 36 bits) typically pair two or four of these parts in parallel, sharing the address and control lines. This limits the part to indoor, temperature-controlled environments (telecom central office, data centre, test equipment). For extended-temperature or outdoor deployment, a wider-range variant would be required. Supply voltage range is 1.7 V to 1.9 V — the core and I/O share a single rail. The 200 mV tolerance means the regulator must hold the rail within ±5.6% of the nominal 1.8 V; a standard 1.8 V LDO with 1% initial accuracy and reasonable load regulation covers this, but the PCB decoupling network must keep dynamic droop below 50 mV during burst reads.
165-ball FBGA — board integration notes
Packaged in a 165-ball LBGA with a 13x15 mm body. Surface-mount on Tape & Reel — the reel format suits high-volume pick-and-place assembly.
Sourcing posture for a Last-Buy part
For a design still using this part, the base product number is CY7C1426. A parametric search on the CY7C1426 family may reveal a currently active speed grade or density variant, but the package and pinout must be verified against the existing PCB layout before substituting.