{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"CY27H256-25ZC","brand":"Infineon Technologies","brandSlug":"infineon","productSlug":"CY27H256-25ZC","canonicalUrl":"https://icboms.com/infineon/CY27H256-25ZC","factsUrl":"https://icboms.com/api/mcp/products/CY27H256-25ZC","rawCanonicalId":null},"summary":{"shortDescription":"Infineon Technologies CY27H256-25ZC UV EPROM, 256Kbit (32K x 8), 25 ns access time, Parallel interface, 4.5V-5.5V supply, 0°C to 70°C, 28-TSOP I package, Bulk.","salesMarkdown":"## 25 ns access UV EPROM for legacy 5V firmware storage The CY27H256-25ZC is a 256Kbit UV-erasable EPROM organized as 32K x 8 bits, with a 25 ns maximum access time. The 25 ns access time sets the read-cycle window for the host CPU or logic — the memory must present valid data within that window from address assertion, which constrains bus timing margins in legacy 5V processor designs. ## UV-EPROM technology and package This device uses UV-EPROM technology, meaning the die is erased by exposure to ultraviolet light through a quartz window in the package. In production, the device is programmed once and treated as a one-time-programmable (OTP) memory — field erasure requires a UV eraser and is practical only during development or rework. The 28-TSOP I package (0.465\" body width, 11.80 mm) is a surface-mount thin small-outline package. The windowed variant allows UV erasure; the non-windowed OTP version is a separate order code. The 28-TSOP I footprint is standard for byte-wide EPROMs of this era and density. The commercial temperature grade (0°C to 70°C) limits deployment to indoor, temperature-controlled environments — not suitable for industrial or automotive ambient extremes without additional qualification data. ## Active lifecycle and compliance note RoHS non-compliant (lead-bearing construction). This is typical for UV-EPROM devices that use a windowed ceramic or plastic package with a lead-frame finish that does not meet the RoHS exemption sunset. Designs requiring RoHS compliance should evaluate the non-windowed OTP variant or a serial-flash migration path.","metaTitle":"Infineon CY27H256-25ZC UV EPROM, 256Kbit, 25 ns, 28-TSOP I","metaDescription":"Infineon CY27H256-25ZC 256Kbit UV EPROM, 25 ns access, 32K x 8, 4.5-5.5V, 28-TSOP I. Active production. RoHS non-compliant. Order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"RoHS non-compliant","productStatus":"Active","categoryPath":["Discrete Semiconductors"],"specifications":{"Package":"Bulk","Technology":"EPROM - UV","Access Time":"25 ns","Memory Size":"256Kbit","Memory Type":"Non-Volatile","Memory Format":"EPROM","Mounting Type":"Surface Mount","Package / Case":"28-TSSOP (0.465\\\", 11.80mm Width)","lifecycle_stage":"eol_hot","Memory Interface":"Parallel","Voltage - Supply":"4.5V ~ 5.5V","Memory Organization":"32K x 8","Operating Temperature":"0°C ~ 70°C (TA)","Supplier Device Package":"28-TSOP I"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$5.74","stockQuantity":0,"priceTiers":[{"qty":53,"price":"$5.74000","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/d1268d1dae044b14a2937202476260fa.pdf","sourceUrl":null},"ai":{"faq":[],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/infineon/CY27H256-25ZC","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/infineon/CY27H256-25ZC when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:49:49.435Z","lastPublished":"2026-08-11T15:49:49.435Z","indexable":true}}