{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"25AA640-I/SN","brand":"Microchip Technology","brandSlug":"microchip","productSlug":"25AA640-I-SN","canonicalUrl":"https://icboms.com/microchip/25AA640-I-SN","factsUrl":"https://icboms.com/api/mcp/products/25AA640-I%2FSN","rawCanonicalId":null},"summary":{"shortDescription":"Microchip 25AA640-I/SN, 64Kbit SPI EEPROM, 1 MHz clock, 1.8V-5.5V supply, 8K x 8 organization, 5ms write cycle, -40°C to 85°C, 8-SOIC package, Tube.","salesMarkdown":"## 64 Kbit SPI EEPROM for parameter storage and calibration tables The Microchip 25AA640-I/SN is a 64Kbit serial EEPROM with an SPI interface, organized as 8K x 8 bits. The 1 MHz maximum clock rate is adequate for boot-time parameter reads and infrequent logging; if your application streams data at higher rates, the 2 MHz 25LC640 sibling is worth a look. The 5 ms write cycle time per word or page means you budget around 2.5 seconds to rewrite the full 64 Kbit array — fine for infrequent updates, not for high-frequency data logging. ROHS3 compliance covers the EU RoHS exemption structure through 2024 and beyond. For dual-sourcing flexibility, the 25AA640A-I/P is a through-hole DIP variant with the same 64Kbit density and SPI interface, though it ships in a different package and may have slight parametric differences — verify the AC timing before dropping it in as a second source. ## SPI bus integration — what the 1 MHz clock means for throughput At 1 MHz SPI clock, a 64-bit read takes about 72 µs including command and address overhead; a full 8K x 8 page read (64 bytes) runs roughly 640 µs. That is fast enough for boot-time configuration pulls and periodic parameter saves, but if your MCU polls the EEPROM at control-loop rates, the bus occupancy will eat into your margin. The write cycle locks out the bus for 5 ms per page — plan your firmware state machine to retry or queue writes. ## Package and footprint — 8-SOIC narrow body The Tube shipping medium is typical for low-volume production and prototyping; if your pick-and-place line prefers tape-and-reel, the 25AA640T-I/SN variant is the reeled version of the same die.","metaTitle":"Microchip 25AA640-I/SN 64Kbit SPI EEPROM, 1 MHz","metaDescription":"Microchip 25AA640-I/SN 64Kbit SPI EEPROM, 1 MHz clock, 1.8V-5.5V supply, -40°C to 85°C, 8-SOIC. Active lifecycle, ROHS3 compliant.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["Microcontrollers & Processors (MCU / MPU / DSP)"],"specifications":{"Package":"Tube","Technology":"EEPROM","Memory Size":"64Kbit","Memory Type":"Non-Volatile","Memory Format":"EEPROM","Mounting Type":"Surface Mount","Package / Case":"8-SOIC (0.154\\\", 3.90mm Width)","Clock Frequency":"1 MHz","lifecycle_stage":"eol_hot","Memory Interface":"SPI","Voltage - Supply":"1.8V ~ 5.5V","Memory Organization":"8K x 8","Operating Temperature":"-40°C ~ 85°C (TA)","Supplier Device Package":"8-SOIC","Write Cycle Time - Word, Page":"5ms"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.9","stockQuantity":0,"priceTiers":[{"qty":1,"price":"$0.90000","currency":"USD"},{"qty":25,"price":"$0.88000","currency":"USD"},{"qty":100,"price":"$0.84000","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/22e74239e894aa11e46d14455dfc5246.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What is the memory size of 25AA640-I/SN?","answer":"The 25AA640-I/SN is a 64Kbit EEPROM organized as 8K x 8 bits."},{"question":"Can 25AA640-I/SN be used as a drop-in replacement for 25LC640?","answer":"Not directly — the 25LC640 runs at 2 MHz SPI clock versus 1 MHz on the 25AA640, and its minimum supply is 2.5V instead of 1.8V. Check the AC timing and supply rail before substituting."},{"question":"What is the difference between 25AA640-I/SN and 25AA640T-I/SN?","answer":"The suffix 'T' indicates tape-and-reel packaging instead of tube. The die and all electrical specifications are identical."},{"question":"Is 25AA640-I/SN RoHS compliant?","answer":"Yes, it is ROHS3 compliant."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/microchip/25AA640-I-SN","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/microchip/25AA640-I-SN 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}}