66.7 MHz synchronous FIFO — 144 Kbit in a 32-PLCC
The CY7C4261-15JXCT is a synchronous FIFO from Infineon's CY7C series, organized 16K x 9 bits for a total of 144 Kbit. It clocks at 66.7 MHz with a 10 ns access time. That supply rail is a legacy 5 V logic level — verify your system's VCC before committing, as many modern controllers have moved to 3.3 V or lower.
Infineon lists the CY7C4261-15JXCT as Obsolete. The part is not available through franchised distribution in production volumes. For BOM sustainment, the part can be sourced through independent distribution on a per-RFQ basis.
32-PLCC J-Lead — footprint and rework considerations
The package is a 32-lead PLCC with J-bend leads, supplier device package 32-PLCC measuring 11.43 x 13.97 mm. The J-Lead footprint is solderable by reflow or wave, but the leads are hidden under the body after soldering — visual inspection of the heel fillet requires an angled scope or X-ray. Surface-mount assembly on a standard FR-4 board is straightforward, but the 5 V supply and 35 mA draw mean the thermal dissipation is low — no heatsinking is needed.
Programmable flags and expansion — depth or width cascading
The FIFO supports programmable flags (almost-full, almost-empty) via the serial or parallel flag-programming method, which lets the system set the threshold levels in software rather than hardwiring them. This is useful for flow control in packet buffers or video line stores. Expansion is supported in both depth and width — multiple devices can be cascaded to build larger buffers without external logic. The part is uni-directional and does not support FWFT (First-Word Fall-Through) or retransmit capability, so the read/write pointer management is handled by the host controller.