{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"CY7C421-20JXI","brand":"Infineon Technologies","brandSlug":"infineon","productSlug":"CY7C421-20JXI","canonicalUrl":"https://icboms.com/infineon/CY7C421-20JXI","factsUrl":"https://icboms.com/api/mcp/products/CY7C421-20JXI","rawCanonicalId":null},"summary":{"shortDescription":"Infineon Technologies CY7C series asynchronous FIFO memory, CY7C421-20JXI, 4.5 Kbit (512 x 9), 20 ns access time, 50 MHz data rate, 5V supply, 32-PLCC (J-Lead), tray.","salesMarkdown":"The CY7C421-20JXI: No stock-holding claim is made here. ## 20 ns access time — timing fit for legacy buses The CY7C421-20JXI is an asynchronous FIFO with a 20 ns access time and a 50 MHz data rate. This means the read/write cycle completes in 20 ns from the address setup — fast enough to interface with older 5V DSPs, microcontrollers, and ASICs that expect a 50 MHz bus without wait states. Memory depth is 4.5 Kbit organized as 512 words by 9 bits wide. The 9-bit width accommodates an 8-bit data byte plus a parity or control bit — common in telecom framer and legacy datacom designs. The FIFO supports depth and width expansion, so multiple devices can cascade for deeper or wider buffers without external logic. Retransmit capability is also present — a feature that resets the read pointer to the last programmed retransmit boundary, useful in packet retry schemes. ## 5V supply, industrial temp, 32-PLCC package This rules out direct drop-in replacement with modern 3.3V or 1.8V FIFOs without a level translator. Packaged in a 32-lead PLCC with J-leads (32-LCC), the supplier device package is 32-PLCC (11.43x13.97 mm). Surface-mount with a standard JEDEC footprint — the J-lead form factor is less common in new designs but well-documented for rework and inspection. Maximum supply current is 90 mA. No FWFT (First-Word Fall-Through) support and no programmable flags — this is a basic asynchronous FIFO with fixed flag logic.","metaTitle":"CY7C421-20JXI Infineon FIFO 4.5K 512x9 20ns 32-PLCC","metaDescription":"CY7C421-20JXI asynchronous FIFO, 4.5 Kbit (512 x 9), 20 ns access time, 50 MHz data rate, 5V supply, -40 to +85°C, 32-PLCC.","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":"Tray","Function":"Asynchronous","Data Rate":"50MHz","Access Time":"20ns","Memory Size":"4.5K (512 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":"7C421","Operating Temperature":"-40°C~85°C","Retransmit Capability":"Yes","Current - Supply (Max)":"90mA","Supplier Device Package":"32-PLCC (11.43x13.97)","Programmable Flags Support":"No"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/4ff2b25f88134e2a3806033ba16d7ff7.pdf","sourceUrl":null},"ai":{"faq":[{"question":"How do I get current pricing and availability for CY7C421-20JXI?","answer":"Submit an RFQ against your target quantity. As an obsolete part, availability is lot-specific and confirmed at quote time through independent surplus channels."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/infineon/CY7C421-20JXI","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/infineon/CY7C421-20JXI when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-21T02:18:48.487Z","lastPublished":"2026-07-21T02:18:48.487Z","indexable":true}}