{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"RN1403,LF","brand":"Toshiba Semiconductor","brandSlug":"toshiba","productSlug":"RN1403LF","canonicalUrl":"https://icboms.com/toshiba/RN1403LF","factsUrl":"https://icboms.com/api/mcp/products/RN1403%2CLF","rawCanonicalId":null},"summary":{"shortDescription":"Toshiba Semiconductor RN1403,LF NPN pre-biased transistor, 50 V collector-emitter breakdown, 100 mA collector current, 22 kOhms base and emitter-base resistors, 250 MHz transition frequency, SOT-23-3 S-Mini package, Tape & Reel.","salesMarkdown":"## Bias resistor network sets the on/off threshold The RN1403,LF integrates a 22 kOhm base resistor (R1) and a 22 kOhm emitter-base resistor (R2) — a 1:1 divider that defines the input voltage at which the transistor turns on. With both resistors equal, the switch-on threshold sits at roughly half the drive voltage, so a 5 V logic signal needs to exceed about 2.5 V at the base pin to saturate the output. This fixed ratio eliminates the external bias resistor pair, saving one component per channel on the board. ## 50 V breakdown and 100 mA continuous collector current Rated for 50 V collector-emitter breakdown and 100 mA continuous collector current, this pre-biased NPN handles typical low-side switching of relay coils, indicator LEDs, or small solenoid valves in 24 V industrial logic circuits. The 200 mW power dissipation limit in the SOT-23-3 package means the actual continuous current at elevated ambient temperature is lower than the 100 mA headline — at 85 °C ambient the derating curve typically halves the allowable dissipation, so a 50 mA load is a safer continuous target without exceeding the junction temperature. ## 250 MHz transition frequency and saturation voltage With a 250 MHz transition frequency, the RN1403,LF switches fast enough for PWM dimming of LEDs at tens of kilohertz or for driving the base of a larger power transistor in a Darlington pair. The minimum DC current gain of 70 at 10 mA collector current ensures the base drive from a microcontroller GPIO (typically 2-5 mA) saturates the output reliably.","metaTitle":"Toshiba RN1403,LF NPN Pre-Biased Transistor, 50V 100mA","metaDescription":"Toshiba RN1403,LF NPN pre-biased transistor, 50V Vceo, 100mA Ic, 22k/22k bias resistors, 250MHz fT, SOT-23-3. Active production, ROHS3 compliant.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["Discrete Semiconductors"],"specifications":{"Package":"Tape & Reel (TR); Cut Tape (CT)","Power - Max":"200 mW","Mounting Type":"Surface Mount","Package / Case":"TO-236-3, SC-59, SOT-23-3","Transistor Type":"NPN - Pre-Biased","lifecycle_stage":"eol_hot","Resistor - Base (R1)":"22 kOhms","Frequency - Transition":"250 MHz","Supplier Device Package":"S-Mini","Resistor - Emitter Base (R2)":"22 kOhms","Vce Saturation (Max) @ Ib, Ic":"300mV @ 250µA, 5mA","Current - Collector (Ic) (Max)":"100 mA","Current - Collector Cutoff (Max)":"500nA","DC Current Gain (hFE) (Min) @ Ic, Vce":"70 @ 10mA, 5V","Voltage - Collector Emitter Breakdown (Max)":"50 V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.21","stockQuantity":15,"priceTiers":[{"qty":1,"price":"$0.21000","currency":"USD"},{"qty":10,"price":"$0.14600","currency":"USD"},{"qty":100,"price":"$0.07110","currency":"USD"},{"qty":500,"price":"$0.05930","currency":"USD"},{"qty":1000,"price":"$0.04121","currency":"USD"},{"qty":3000,"price":"$0.03571","currency":"USD"},{"qty":6000,"price":"$0.03313","currency":"USD"},{"qty":9000,"price":"$0.02747","currency":"USD"},{"qty":30000,"price":"$0.02699","currency":"USD"},{"qty":75000,"price":"$0.02424","currency":"USD"},{"qty":150000,"price":"$0.02101","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/5e97fde5b75aeb3cafeea0515fe59844.pdf","sourceUrl":null},"ai":{"faq":[{"question":"How does the RN1403,LF compare to the RN1408,LF?","answer":"Both share the same 50 V breakdown, 100 mA collector current, 250 MHz transition frequency, and 22 kOhm base resistor. The difference is the emitter-base resistor: the RN1403,LF uses 22 kOhms (1:1 ratio), while the RN1408,LF uses 47 kOhms (roughly 1:2 ratio). This shifts the turn-on threshold — the RN1403,LF switches at a lower input voltage than the RN1408,LF for the same drive signal."},{"question":"What package does the RN1403,LF use?","answer":"The RN1403,LF is supplied in a TO-236-3 / SC-59 / SOT-23-3 surface-mount package, designated as S-Mini by Toshiba."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/toshiba/RN1403LF","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/toshiba/RN1403LF when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-22T19:45:10.375Z","lastPublished":"2026-07-22T19:45:10.375Z","indexable":true}}