Synchronous ZBT SRAM for high-throughput data paths
The Renesas 71V65603S100BGI is a 9 Mbit synchronous SRAM organized 256K x 36, built on a Zero Bus Turnaround (ZBT) architecture. It runs at a 100 MHz clock with a 5 ns access time, meaning the memory can deliver a new data word every clock cycle without dead cycles between read and write operations.
The 5 ns access time is the time from address assertion to valid data on the outputs. At 100 MHz the clock period is 10 ns, so the memory has half a cycle to drive the bus. This leaves a tight but workable margin for trace delay and setup time on the controller side. The ZBT feature eliminates the idle cycle normally needed when switching from read to write, so sustained throughput can hit 100 million transactions per second. Designs that need to maintain full bus utilization — packet processing, real-time control loops — benefit directly.
The supply range of 3.135 V to 3.465 V (3.3 V nominal ±5%) is standard for 3.3 V logic families; the 5 ns access time is specified across the full voltage and temperature window, not just at nominal.
Package and footprint: 119-PBGA (14x22 mm)
Housed in a 119-ball PBGA measuring 14x22 mm, the 71V65603S100BGI is a surface-mount BGA. The 119-ball count and 1.27 mm ball pitch are common for mid-density synchronous SRAMs. The BGA package keeps signal inductance low, which helps maintain signal integrity at 100 MHz. Board layout should follow the supplier's recommended footprint and route the 36-bit data bus with matched trace lengths.
The 71V65603S100BGI is listed as Active.