{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"CY7C4251-10JXCT","brand":"Infineon Technologies","brandSlug":"infineon","productSlug":"CY7C4251-10JXCT","canonicalUrl":"https://icboms.com/infineon/CY7C4251-10JXCT","factsUrl":"https://icboms.com/api/mcp/products/CY7C4251-10JXCT","rawCanonicalId":null},"summary":{"shortDescription":"Cypress CY7C4251-10JXCT, Series CY7C, Synchronous FIFO, 100 MHz data rate, 8 ns access time, 72K (8K x 9), 4.5 V~5.5 V supply, 0°C~70°C, 32-PLCC (J-Lead).","salesMarkdown":"The Cypress CY7C4251-10JXCT is a synchronous FIFO memory in the CY7C series, organized 8K x 9 bits (72K total) and clocked at 100 MHz with an 8 ns access time. This part was designed for moderate-depth buffering in data-acquisition, telecom, and processor-to-peripheral links where a 9-bit width (data plus parity or control) and synchronous clocking keep the bus simple. ## 8 ns access time — timing margin at 100 MHz At 100 MHz the clock period is 10 ns. An 8 ns access time leaves 2 ns for setup and hold on the receiving side — tight but workable if the board layout keeps trace lengths matched and the clock jitter under 200 ps. The synchronous interface eliminates the dead cycles you get with asynchronous FIFOs; the read and write pointers advance on the clock edge, so back-to-back transfers are possible. If your system runs slower than 100 MHz, the margin improves proportionally. ## 72K (8K x 9) — what the depth buys you 8K words of 9 bits each is a moderate buffer depth — enough to absorb bursts in a UART-to-processor link, a parallel ADC data stream, or a small packet buffer. The 9th bit is often used for parity or a control flag. Depth and width expansion are supported, so two or more of these can be cascaded for larger buffers without external logic. ## Obsolete — the sourcing reality This part is listed as obsolete. That means the only channel is surplus or broker stock. If you are repairing a board that uses this FIFO, the scorch mark is probably not on the FIFO itself — check the supply rail first, because the 35 mA max draw rarely kills the chip. For new designs, look at current-generation synchronous FIFOs from Cypress (now Infineon) or compatible parts from IDT/Renesas in the same 32-PLCC footprint, but verify pin compatibility against the datasheet before ordering. The 32-PLCC (J-Lead) package (supplier device package 32-PLCC 11.43x13.97 mm) is a surface-mount form factor that was common through the 1990s and 2000s. Replacing it on a board requires hot-air rework with a J-lead nozzle; the pads are under the body, so inspection after soldering needs an X-ray or a borescope.","metaTitle":"CY7C4251-10JXCT Synchronous FIFO, 8 ns Access, 72K, 32-PLCC","metaDescription":"Cypress CY7C4251-10JXCT synchronous FIFO, 100 MHz data rate, 8 ns access time, 72K (8K x 9) memory. Quoted on request.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Obsolete","categoryPath":["Memory (DRAM / SRAM / Flash / EEPROM)"],"specifications":{"Mfr":"Infineon Technologies","Series":"CY7C","Package":"Tape & Reel (TR)","Function":"Synchronous","Data Rate":"100MHz","Access Time":"8ns","Memory Size":"72K (8K x 9)","FWFT Support":"No","Mounting Type":"Surface Mount","Expansion Type":"Depth, Width","Package / Case":"32-LCC (J-Lead)","Product Status":"Obsolete","Bus Directional":"Uni-Directional","lifecycle_stage":"eol_hot","Voltage - Supply":"4.5 V ~ 5.5 V","Base Product Number":"7C4251","Operating Temperature":"0°C~70°C","Retransmit Capability":"No","Current - Supply (Max)":"35mA","Supplier Device Package":"32-PLCC (11.43x13.97)","Programmable Flags Support":"Yes"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/b0115a44e89566724ee3f49375c67cf8.pdf","sourceUrl":null},"ai":{"faq":[{"question":"Is CY7C4251-10JXCT obsolete?","answer":"Yes, the CY7C4251-10JXCT is listed as obsolete. It is no longer in production. For existing designs, source from surplus or broker channels; for new designs, evaluate a current-generation synchronous FIFO in a similar 32-PLCC footprint."},{"question":"What is the access time of CY7C4251-10JXCT?","answer":"The access time is 8 ns, which at a 100 MHz clock rate leaves 2 ns of timing margin for setup and hold on the receiving bus."},{"question":"What is the difference between synchronous and asynchronous FIFO?","answer":"A synchronous FIFO like the CY7C4251 uses a clock to latch read and write operations on every edge, enabling back-to-back transfers without dead cycles. An asynchronous FIFO uses separate read and write strobes and requires handshaking, which adds latency but can bridge different clock domains without a PLL."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/infineon/CY7C4251-10JXCT","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/infineon/CY7C4251-10JXCT when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-17T19:50:00.618Z","lastPublished":"2026-07-17T19:50:00.618Z","indexable":true}}