28-DIP asynchronous FIFO, 512 x 9, 25 ns access
The SN74ACT7201LA25NP is a 512-word by 9-bit asynchronous FIFO from Texas Instruments, with a 25 ns access time and a 28.5 MHz data rate. The 28-pin DIP (0.300-inch body) through-hole package suits legacy bus architectures or prototyping where a socketed memory buffer is preferred over surface-mount. Operating from a single 5 V supply (4.5 V to 5.5 V range), it draws a maximum of 125 mA. The commercial temperature grade (0°C to 70°C) covers indoor equipment and benchtop instruments.
Asynchronous operation with retransmit capability
The FIFO is asynchronous — separate read and write clocks are not required; data transfers are controlled by independent read and write enable signals. This simplifies the interface for systems that already have separate read/write strobes and do not need a free-running clock. It supports depth and width expansion, so multiple devices can be cascaded for deeper or wider buffers without glue logic. Retransmit capability allows the same data block to be re-read from the beginning — useful in retry protocols or diagnostic loops. First-word fall-through (FWFT) is not supported, and programmable flags are absent. The empty and full flags are hardwired; the designer must manage flag timing externally if the system requires threshold-based flow control.
Active lifecycle and sourcing posture
The 28-DIP footprint is unique to this variant; a board spin would be required to migrate to a surface-mount FIFO from the same family.