{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"71256L55TDB","brand":"Renesas Electronics","brandSlug":"renesas","productSlug":"71256L55TDB","canonicalUrl":"https://icboms.com/renesas/71256L55TDB","factsUrl":"https://icboms.com/api/mcp/products/71256L55TDB","rawCanonicalId":null},"summary":{"shortDescription":"Renesas Electronics 71256L55TDB asynchronous SRAM, 256Kbit (32K x 8), 55 ns access time, 4.5V-5.5V supply, -55°C to 125°C, 28-CDIP ceramic DIP, Bulk.","salesMarkdown":"## 256Kbit asynchronous SRAM in hermetic ceramic DIP The Renesas Electronics 71256L55TDB is a 256 Kbit parallel asynchronous SRAM organized as 32K x 8 bits, with a 55 ns access time. The hermetic ceramic package and wide temperature grade target deployment in avionics, missile guidance, satellite subsystems, and downhole instrumentation where plastic-packaged commercial or industrial SRAMs cannot survive thermal cycling or outgassing requirements. ## 55 ns access time and asynchronous interface The 55 ns access time (tAA) governs the read-cycle timing: the address-to-data-valid delay. For a CPU or DSP with a 12.5 MHz bus clock (80 ns cycle), this SRAM fits without wait states. The write cycle time, word/page, is also 55 ns, so the bus master must hold the write strobe and data valid for at least that window. As an asynchronous device, the 71256L55TDB requires no clock input — the chip-enable (CE) and output-enable (OE) pins gate the data bus directly. This simplifies board routing and timing closure in point-to-point or low-density memory maps compared to synchronous SRAMs that need a free-running clock and PLL. ## Package, temperature grade, and board integration The ceramic body is hermetically sealed; no moisture sensitivity level (MSL) rating applies, so no bake-out is needed before reflow or hand-soldering. Decoupling should follow the usual 0.1 µF ceramic per supply pin, placed within 0.25 inches of the VCC and GND pins, with a bulk 10 µF tantalum near the device on the 5V rail.","metaTitle":"Renesas 71256L55TDB 256Kbit SRAM, 55ns, 28-CDIP","metaDescription":"Renesas Electronics 71256L55TDB 256Kbit parallel asynchronous SRAM, 55ns access time, 32K x 8, 28-CDIP ceramic DIP, -55°C to 125°C.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Microcontrollers & Processors (MCU / MPU / DSP)"],"specifications":{"Package":"Bulk","Technology":"SRAM - Asynchronous","Access Time":"55 ns","Memory Size":"256Kbit","Memory Type":"Volatile","Memory Format":"SRAM","Mounting Type":"Through Hole","Package / Case":"28-CDIP (0.300\\\", 7.62mm)","lifecycle_stage":"eol_hot","Memory Interface":"Parallel","Voltage - Supply":"4.5V ~ 5.5V","Memory Organization":"32K x 8","Operating Temperature":"-55°C ~ 125°C (TA)","Supplier Device Package":"28-CDIP","Write Cycle Time - Word, Page":"55ns"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$21.33","stockQuantity":23,"priceTiers":[{"qty":15,"price":"$21.33000","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/12106deaaf0f0d18010bfc0bef6f754a.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What is the access time and memory organization of the 71256L55TDB?","answer":"The 71256L55TDB has a 55 ns access time and is organized as 32K x 8 bits (256 Kbit total). Both read and write cycle times are 55 ns."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/renesas/71256L55TDB","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/renesas/71256L55TDB when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-22T19:45:10.375Z","lastPublished":"2026-07-22T19:45:10.375Z","indexable":true}}