{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"HM1-6551/883","brand":"Renesas Electronics","brandSlug":"renesas","productSlug":"HM1-6551-883","canonicalUrl":"https://icboms.com/renesas/HM1-6551-883","factsUrl":"https://icboms.com/api/mcp/products/HM1-6551%2F883","rawCanonicalId":null},"summary":{"shortDescription":"HM1-6551/883, 1Kbit (256 x 4) parallel SRAM, 300 ns access time, 4.5V supply, Through Hole, 22CDIP, -55°C to 125°C military temperature range.","salesMarkdown":"## 1Kbit parallel SRAM in a ceramic DIP — what you're looking at The HM1-6551/883 is a 1Kbit (organized 256 x 4) parallel SRAM from the 883-series, built in a hermetic 22-lead ceramic DIP (22CDIP) for through-hole mounting. It runs on a single 4.5V supply and delivers a 300 ns access time with a 400 ns write cycle. The memory is volatile — data persists only while power is applied — and uses a straightforward parallel interface with no clock or multiplexing. For a controller running at 4.5V, this is a relaxed timing window — you'll have no trouble interfacing with a slow 8-bit microcontroller or a legacy 6800/8085-style bus. But if you're trying to hang this on a fast 16-bit or 32-bit processor that expects sub-100 ns SRAM, you'll need wait states or a slower clock divider. The 400 ns write cycle time is similarly relaxed: the write pulse must be held long enough for the internal bit lines to settle. For a BOM engineer, this part fits designs where bus speed is not the priority — think telemetry data logging at a few hundred kHz, configuration register storage, or a small FIFO buffer in a system that already runs at a few MHz. This is not a commercial or industrial part that happens to survive cold — it's screened and specified to guarantee operation across that entire span. The 883 suffix in the part number indicates it was originally processed to MIL-STD-883 requirements, which means lot-level testing, temperature cycling, burn-in, and hermeticity verification. For a procurement desk, this is the part you spec when the board goes into an engine bay, a satellite sun-synchronous orbit, or a radar pod that freezes at altitude. The ceramic DIP package (22CDIP) is hermetic — it won't absorb moisture or outgas in vacuum, unlike plastic packages. That matters for sealed assemblies and long-life missions where conformal coating alone isn't enough. ## Package reality — 22CDIP and how it sits on the board The 22-lead ceramic DIP (22CDIP) is a through-hole package with leads on 0.3-inch row spacing, standard 0.1-inch pin pitch. It's a dual-in-line body, so it plugs into a 22-pin socket or solders into plated through-holes. For rework: this package is a dream compared to a QFN or BGA. You can desolder it with a vacuum desoldering station or even careful hot-air from the bottom side without lifting pads. The ceramic body handles the heat — it won't melt or delaminate like plastic. The through-hole mounting means it's mechanically robust: it won't shake loose in a high-vibration environment the way a large PLCC might. Just make sure your board has the 0.3-inch row spacing — this is not a skinny 0.3-inch DIP; it's the wider 0.6-inch row spacing typical of 24-pin and larger DIPs. ## Lifecycle and supply posture This is not an obsolete or NRND part that requires a last-time-buy calculation. For a design engineer, that means you can spec it into a new military or aerospace program without worrying about a mid-production EOL notice. No lead-time number is published here, but the active status means the supply chain is stable — no urgent broker scramble needed.","metaTitle":"HM1-6551/883 SRAM, 1Kbit Parallel, 300 ns, -55°C to 125°C","metaDescription":"HM1-6551/883 1Kbit parallel SRAM in 22CDIP, 300 ns access time, 4.5V supply, military temp range -55°C to 125°C.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Memory (DRAM / SRAM / Flash / EEPROM)"],"specifications":{"frame_size":"1Kbit","Access Time":"300 ns","memory_type":"Volatile","package_type":"Bulk","Memory Format":"SRAM","mounting_type":"Through Hole","interface_type":"Parallel","product_status":"Active","lifecycle_stage":"eol_hot","supply_voltage_v":"4.5","Memory Organization":"256 x 4","Operating Temperature High":"-55°C to 125°C(TA)","Write Cycle Time - Word, Page":"400ns"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$25.43","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/a6285f7dbb9478733d58b3898faf557b.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What is the HM1-6551/883's memory size and organization?","answer":"The HM1-6551/883 is a 1Kbit SRAM organized as 256 words by 4 bits (256 x 4). It uses a parallel interface and operates from a single 4.5V supply."},{"question":"What is the access time and write cycle time for HM1-6551/883?","answer":"The access time is 300 ns, and the write cycle time (word or page) is 400 ns. These are relaxed timing specs suitable for slow-to-moderate speed bus interfaces."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/renesas/HM1-6551-883","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/renesas/HM1-6551-883 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}}