GS840Z18/36AT-180/166/150/100 is a 4Mb Synchronous Static SRAM from GSI Technology that supports No Bus Turn Around for zero wait read-write-read bus utilization.
The GS840Z18/36AT is a 4 Mb synchronous NBT SRAM offered by GSI Technology. It supports user‑configurable Pipeline and Flow‑Through modes, delivering full bus utilization with zero wait read‑write‑read cycles. The device is available in 100‑lead TQFP packages and is pin‑compatible with a range of 2 M, 8 M and 16 M SRAMs.
The datasheet includes feature highlights, functional description, pin‑out diagrams, pin descriptions, timing diagrams, truth tables, state diagrams, ordering information, and revision history. It also lists electrical specifications such as supply voltages, speed ranges, and current consumption for the various speed grades.
| Configurations | 256K × 18 and 128K × 36 |
|---|---|
| Core supply voltage | 3.3 V +10%/‑5% |
| I/O supply voltage | 2.5 V or 3.3 V |
| Package | JEDEC‑standard 100‑lead TQFP |
| Speed range | 480 MHz‑100 MHz |
| Cycle time (180 MHz grade) | 5.5 ns |
It can be configured by the user to operate in either Pipeline mode or Flow‑Through mode, both providing NBT functionality.
The ZZ pin provides automatic power‑down when asserted high.
It is fully pin‑compatible with NtRAM™, NoBL™ and ZBT™ SRAMs, as well as with 2 M, 8 M and 16 M devices.