{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"MM74HC243N","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"MM74HC243N","canonicalUrl":"https://icboms.com/texas-instruments/MM74HC243N","factsUrl":"https://icboms.com/api/mcp/products/MM74HC243N","rawCanonicalId":null},"summary":{"shortDescription":"74HC series, Buffer, Non-Inverting, 2V ~ 6V supply, 2 elements x 4 bits, Through Hole, 20-DIP (0.300\", 7.62mm), 20-PDIP.","salesMarkdown":"The MM74HC243N is a 74HC-series non-inverting buffer from the standard CMOS logic family, packaged in a through-hole 20-pin DIP. It contains two independent 4-bit buffer elements, each capable of driving moderate loads from a 2V to 6V supply rail. This part is a drop-in choice for legacy through-hole boards, breadboard prototyping, or designs where a simple signal buffer with no inversion is needed — common in industrial control panels, relay drivers, or as a level translator between 3.3V and 5V domains within the 74HC supply range. ## Supply voltage and logic family — the fit decision The 2V to 6V supply range is the defining parameter for BOM fit. If your system rail is 3.3V or 5V, the MM74HC243N works directly. The 74HC family offers higher noise margin than the older 74LS series at the same supply, but input thresholds are CMOS-level (not TTL), so driving it from a 5V TTL output may need a pull-up. The 2-element, 4-bit-per-element architecture means you get two independent 4-bit buffers in one package — useful for splitting a byte-wide bus into two nibbles or buffering two separate 4-bit groups. The 20-DIP (0.300\" body width, 7.62mm lead pitch) is a through-hole package that is straightforward to hand-solder or rework. No hot-air station needed — a standard iron lifts it cleanly. The 20-PDIP footprint is common across many 20-pin logic parts, so board layout is standard. The RoHS non-compliant status means this part contains lead in the solder finish; it is exempt for certain industrial or military applications but cannot be used in RoHS-mandated consumer electronics without a specific exemption. For dual-sourcing or a higher-speed alternative, the SN74LS645-1N is a 74LS-series 8-bit transceiver in the same 20-DIP footprint, but note it is a bidirectional transceiver with TTL-level inputs and a narrower 4.75V supply tolerance — not a direct electrical replacement, but a functional alternative for designs that can accept the logic family change.","metaTitle":"MM74HC243N 74HC Buffer Non-Inverting, 2V-6V, 20-DIP","metaDescription":"MM74HC243N 74HC series buffer, non-inverting, 2V to 6V supply, 2 elements x 4 bits, through-hole 20-DIP. Active production, RoHS non-compliant.","metaKeywords":null},"attributes":{"series":"74HC","packageCase":null,"mountingType":null,"rohsStatus":"RoHS non-compliant","productStatus":"Active","categoryPath":["Logic ICs"],"specifications":{"Series":"74HC","Package":"Bulk","Logic Type":"Buffer, Non-Inverting","Mounting Type":"Through Hole","Package / Case":"20-DIP (0.300\\\", 7.62mm)","lifecycle_stage":"eol_hot","Voltage - Supply":"2V ~ 6V","Number of Elements":"2","Supplier Device Package":"20-PDIP","Number of Bits per Element":"4"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.34","priceTiers":[{"qty":875,"price":"$0.34000","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/c889939a32b0707485d7f2f9a1d7f4fe.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/MM74HC243N/alternatives.json"},"ai":{"faq":[{"question":"What is the equivalent or replacement for MM74HC243N?","answer":"A functional alternative in the same 20-DIP footprint is the SN74LS645-1N, but it is an 8-bit transceiver (bidirectional) from the 74LS family with a 4.75V supply — not a direct pin-for-pin replacement. For a CMOS-level buffer, stick with the 74HC family. No exact second-source is listed on this record."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/MM74HC243N","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/MM74HC243N 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}}