{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"SN74LS645N3","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"SN74LS645N3","canonicalUrl":"https://icboms.com/texas-instruments/SN74LS645N3","factsUrl":"https://icboms.com/api/mcp/products/SN74LS645N3","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments 74LS series bus transceiver, SN74LS645N3, 8-bit non-inverting, 3-state outputs, through-hole 20-DIP (0.300\", 7.62 mm), 4.75-5.25 V supply, 0°C to 70°C.","salesMarkdown":"## 8-bit bidirectional bus buffer for 5 V TTL backplanes The SN74LS645N3 is an 8-bit non-inverting transceiver from TI's 74LS low-power Schottky TTL family, with 3-state outputs on both the A and B ports. It buffers bidirectional data between two 8-bit buses under direction (DIR) and output-enable (OE) control. Output drive is rated 15 mA source and 24 mA sink per channel — enough to drive a standard TTL load or a short backplane trace, but not a heavily loaded parallel bus without external buffers. The 3-state outputs let multiple transceivers share the same bus lines without contention. ## Supply rail and temperature grade No wide-VIN flexibility; a regulated 5 V supply is required. This limits deployment to indoor, temperature-controlled equipment — not suitable for industrial enclosures, automotive, or outdoor use without environmental mitigation. Housed in a 20-pin plastic DIP (0.300\" wide, 7.62 mm body), through-hole mounting. The supplier device package is 20-PDIP. This is a legacy footprint — no SMD rework possible; the part inserts into a socket or solders into plated through-holes on a 100-mil pitch grid. Supplied in bulk packaging (loose tubes or bags), not tape-and-reel. For high-volume pick-and-place, the tube-packed SN74LS645-1N is the same die in the same package but shipped in tubes. RoHS non-compliant. The part uses a tin-lead (SnPb) finish on the leads. This is acceptable for RoHS-exempt applications (military, aerospace, medical implants, some industrial spares) and for prototypes where leaded solder is still used. For RoHS-required builds, a lead-free alternative from the 74LS family (e.g., SN74LS645N) should be verified for pin-compatibility.","metaTitle":"SN74LS645N3 74LS Transceiver, Non-Inverting, 8-bit, 20-DIP","metaDescription":"TI SN74LS645N3 8-bit bus transceiver, 4.75-5.25 V, 15/24 mA drive, 0-70°C, 20-DIP. Active production. RoHS non-compliant. Sourced to order.","metaKeywords":null},"attributes":{"series":"74LS","packageCase":null,"mountingType":null,"rohsStatus":"RoHS non-compliant","productStatus":"Active","categoryPath":["Microcontrollers & Processors (MCU / MPU / DSP)"],"specifications":{"Series":"74LS","Package":"Bulk","Logic Type":"Transceiver, Non-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":"$0.44","priceTiers":[{"qty":687,"price":"$0.44000","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/296d9486f6e297130953e9032e85d6b4.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/SN74LS645N3/alternatives.json"},"ai":{"faq":[{"question":"Will SN74LS645N3 drop into a board designed for SN74LS645-1N?","answer":"Yes — the SN74LS645-1N is the tube-packaged variant of the same die in the same 20-pin DIP package. Pinout, logic function, and electrical specs are identical. The only difference is packaging format (bulk vs tube)."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/SN74LS645N3","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/SN74LS645N3 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}}