{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"SN74LS640-1N","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"SN74LS640-1N","canonicalUrl":"https://icboms.com/texas-instruments/SN74LS640-1N","factsUrl":"https://icboms.com/api/mcp/products/SN74LS640-1N","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments 74LS series, SN74LS640-1N inverting bus transceiver, 8-bit, 3-state outputs, 15 mA / 48 mA drive, 4.75-5.25 V supply, 20-pin DIP (0.300\"), through-hole, 0-70 °C, tube.","salesMarkdown":"## 8-bit inverting bus transceiver — 15 mA / 48 mA output drive The SN74LS640-1N is an 8-bit inverting transceiver from Texas Instruments' 74LS low-power Schottky family, with 3-state outputs that let it drive or isolate a bidirectional data bus. The 15 mA output-high and 48 mA output-low current ratings set the fan-out limit: at 5 V TTL levels, each output can drive up to 10 standard LS loads without external buffers, making it a direct fit for 8-bit microprocessor buses, memory interfaces, or peripheral backplanes where inversion is needed on the data direction. ## Pin-compatible alternative — SN74LS645-1N non-inverting version The closest peer is the SN74LS645-1N, which is identical in every parametric except logic type: the 645 is a non-inverting transceiver, while the 640 inverts. Both share the same 20-DIP package, 4.75-5.25 V supply, 15 mA / 48 mA drive, and 0-70 °C temperature range. A board laid out for the SN74LS640-1N accepts the SN74LS645-1N without any wiring change — the pinout is the same; only the data polarity on the bus differs. If the system requires non-inverted data, the 645 is a drop-in swap.","metaTitle":"SN74LS640-1N Texas Instruments 74LS Inverting Transceiver","metaDescription":"Texas Instruments SN74LS640-1N 74LS inverting transceiver, 8-bit, 3-state outputs, 15/48 mA drive, 4.75-5.25 V, 20-DIP, RoHS3.","metaKeywords":null},"attributes":{"series":"74LS","packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["Analog & Data Acquisition"],"specifications":{"Series":"74LS","Package":"Tube","Logic Type":"Transceiver, Inverting","Output Type":"3-State","Mounting Type":"Through Hole","Package / Case":"20-DIP (0.300\\\", 7.62mm)","lifecycle_stage":"eol_hot","Voltage - Supply":"4.75V ~ 5.25V","Number of Elements":"1","Operating Temperature":"0°C ~ 70°C (TA)","Supplier Device Package":"20-PDIP","Current - Output High, Low":"15mA, 48mA","Number of Bits per Element":"8"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$2.35","stockQuantity":0,"priceTiers":[{"qty":1,"price":"$2.35000","currency":"USD"},{"qty":10,"price":"$2.10700","currency":"USD"},{"qty":25,"price":"$1.98760","currency":"USD"},{"qty":100,"price":"$1.69340","currency":"USD"},{"qty":250,"price":"$1.59000","currency":"USD"},{"qty":500,"price":"$1.39124","currency":"USD"},{"qty":1000,"price":"$1.15275","currency":"USD"},{"qty":2500,"price":"$1.12500","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/296d9486f6e297130953e9032e85d6b4.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What is the closest functional second-source for SN74LS640-1N?","answer":"The SN74LS645-1N is the pin-compatible non-inverting version — same package, supply, drive current, and temperature range. It drops into the same board without rewiring; only the data polarity differs."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/SN74LS640-1N","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/SN74LS640-1N 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}}