{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"SN74LS640N3","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"SN74LS640N3","canonicalUrl":"https://icboms.com/texas-instruments/SN74LS640N3","factsUrl":"https://icboms.com/api/mcp/products/SN74LS640N3","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments 74LS series, SN74LS640N3, Bus Transceiver, Inverting, 3-State, Through Hole, 20-DIP (0.300\", 7.62mm), 4.75V–5.25V supply, 0°C to 70°C.","salesMarkdown":"## Inverting bus transceiver for 5 V TTL backplanes The SN74LS640N3: Its 3-state outputs let multiple transceivers share the same bus lines without contention. The inverting logic (data on the A bus appears inverted on the B bus) is a deliberate choice for active-low control schemes or when the bus polarity must be flipped. The SN74LS640N3 can source 15 mA and sink 24 mA per output. The 3-state control (active-low output enable) lets you disconnect the transceiver from the bus when another device is driving. ## Package and retrofit fit Housed in a 20-pin DIP with 0.300-inch row spacing, the SN74LS640N3 is a direct drop-in for sockets or wave-solder holes on legacy PCBs. The through-hole mounting means no reflow profile changes — just hand-solder or wave-solder it in. This is important for long-life equipment that needs a guaranteed supply of spare parts.","metaTitle":"SN74LS640N3 Bus Transceiver, Inverting, 20-DIP, 15mA/24mA","metaDescription":"Texas Instruments SN74LS640N3 inverting bus transceiver with 3-state outputs, 4.75V–5.25V supply, 20-pin DIP.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"RoHS non-compliant","productStatus":"Active","categoryPath":["Logic ICs"],"specifications":{"Package":"Bulk","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":"$0.41","priceTiers":[{"qty":740,"price":"$0.41000","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/296d9486f6e297130953e9032e85d6b4.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/SN74LS640N3/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy SN74LS640N3?","answer":"Submit a request for quote and we will confirm availability and current pricing at quote time."},{"question":"What is the difference between SN74LS640 and SN74LS245?","answer":"The SN74LS640 is an inverting transceiver — data on the A bus appears inverted on the B bus. The SN74LS245 is non-inverting. Both are 8-bit, 3-state, 20-pin DIP parts with the same pinout; the choice depends on whether your bus needs polarity inversion."},{"question":"What is the equivalent of SN74LS640N3?","answer":"The closest functional alternative is the SN74LS645-1N, which is also an 8-bit transceiver in the same 20-pin DIP package but non-inverting. If bus polarity is not a constraint, it is a drop-in replacement for dual-sourcing."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/SN74LS640N3","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/SN74LS640N3 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}}