{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"SN74LS640N","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"SN74LS640N","canonicalUrl":"https://icboms.com/texas-instruments/SN74LS640N","factsUrl":"https://icboms.com/api/mcp/products/SN74LS640N","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments 74LS series SN74LS640N, Inverting Transceiver with 3-State outputs, Through Hole 20-DIP (0.300\", 7.62mm), 4.75V ~ 5.25V supply, 0°C ~ 70°C operating temperature.","salesMarkdown":"## Inverting octal bus transceiver — what it changes on the bus The SN74LS640N is a single-element 8-bit bus transceiver from TI's 74LS family with an inverting data path. ## Through-hole DIP — field-swappable without a hot-air station The 20-pin DIP package is socket-friendly. If you are maintaining legacy boards in the field, you can swap this part with a standard IC puller and a soldering iron — no hot air, no reflow profile. That is a real advantage when the customer's machine is down and you are working off a workbench, not a lab. ## Output drive: 15 mA source, 24 mA sink The SN74LS640N can source 15 mA and sink 24 mA per output. That is standard 74LS drive strength — enough to fan out to ten 74LS loads or drive a terminated backplane trace. If your bus needs more current, look at the 74ABT or 74F families; but for a straight TTL bus, this is the right current budget. The 3-state outputs let multiple transceivers share the same bus lines without contention, as long as the output-enable logic is sequenced correctly. ## Active lifecycle — still a current-production part No last-time-buy notice, no phase-out. ROHS3 compliant, so it passes modern environmental requirements.","metaTitle":"SN74LS640N 74LS Inverting Transceiver, 20-DIP, 3-State","metaDescription":"Texas Instruments SN74LS640N 74LS inverting octal bus transceiver. 3-state outputs, 15mA/24mA drive, 4.75-5.25V supply, 0-70°C. Active lifecycle.","metaKeywords":null},"attributes":{"series":"74LS","packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["Logic ICs"],"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, 24mA","Number of Bits per Element":"8"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$2.35","priceTiers":[{"qty":1,"price":"$2.35000","currency":"USD"},{"qty":10,"price":"$2.10800","currency":"USD"},{"qty":25,"price":"$1.98880","currency":"USD"},{"qty":100,"price":"$1.69460","currency":"USD"},{"qty":250,"price":"$1.59120","currency":"USD"},{"qty":500,"price":"$1.39228","currency":"USD"},{"qty":1000,"price":"$1.15361","currency":"USD"},{"qty":2500,"price":"$1.12584","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/296d9486f6e297130953e9032e85d6b4.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/SN74LS640N/alternatives.json"},"ai":{"faq":[{"question":"What is the difference between SN74LS640N and SN74LS245?","answer":"The SN74LS640N is an inverting transceiver, while the SN74LS245 is non-inverting. On the SN74LS640N, data passes through inverted — a high on the A bus becomes a low on the B bus. The SN74LS245 passes data straight through. Both are 8-bit, 3-state, 20-pin DIP parts with similar drive and supply specs. Choose the 640N when your bus polarity needs flipping."},{"question":"Can SN74LS640N replace SN74LS245?","answer":"Only if your design requires inverted bus polarity. The SN74LS640N and SN74LS245 share the same 20-pin DIP footprint, supply voltage range, and 3-state outputs, but the 640N inverts the data path. Swapping one for the other without changing the board logic will invert all bus signals."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/SN74LS640N","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/SN74LS640N 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}}