Synchronous SRAM for high-throughput data buffering
The Renesas 71V2556SA133BGI is a 4.5 Mbit synchronous SRAM organized as 128K x 36 bits, using a Zero Bus Turnaround (ZBT) architecture that eliminates dead cycles between read and write operations on the same data bus. Rated for a 133 MHz clock and a 4.2 ns access time, this part is suited for high-throughput data buffering in networking, telecom, and test equipment where the bus must switch direction every cycle without a wait state.
119-PBGA footprint and layout considerations
Housed in a 119-ball PBGA (14x22 mm body), the part requires a multi-layer PCB for fan-out of the fine-pitch BGA balls — the 0.80 mm or 1.00 mm ball pitch typical of this package family does not route out on two layers.