MMBT4401

MMBT2222A is an onsemi NPN small-signal switching transistor in SOT-23 — 40 V collector-emitter voltage, 600 mA continuous collector current, DC current gain of 100 minimum, 300 MHz transition frequency, 350 mW dissipation, -55 to +150 °C, tape-and-reel packing. The SOT-23 package is the selection point: the SMD version of the classic 2N2222A for reflow assembly, keeping the same 40 V/600 mA ratings in a fraction of the board area. Selection advice: the A suffix is the higher-voltage grade — the plain MMBT2222 is only 30 V, so match the full MMBT2222A code. The 350 mW dissipation is lower than the TO-92 version, so derate switching loads accordingly. Evidence: onsemi/Diodes MMBT2222A datasheets and distributor listings confirm NPN, 40 V, 600 mA, 300 MHz and SOT-23. Match the full MMBT2222A code — the A suffix matters for voltage rating. State quantity, packing and date-code requirements in your RFQ; we reconfirm the offered lot before quotation and reply within 24 hours.

Diotec lists MMBT3904 as active — an NPN bipolar junction transistor, VCEO 40 V, IC 200 mA, 0.35 W, SOT-23 package, 150 °C junction temperature. The MMBT3904 is the SMD incarnation of the classic 2N3904: identical die characteristics in a SOT-23 footprint for automated assembly. Selection advice: confirm your circuit was designed for the SMD package — the through-hole 2N3904 and MMBT3904 are electrically equivalent but not footprint-compatible. The complementary PNP is the MMBT3906; for push-pull or complementary stages, source both from the same manufacturer to keep gain grades matched. Parameters verified against the Diotec official product page. State quantity, packing and date-code requirements in your RFQ; we reconfirm the offered lot before quotation and reply within 24 hours.

2N4401 is an onsemi NPN silicon general-purpose transistor — 40 V collector-emitter voltage, 600 mA continuous collector current, DC current gain of 100 minimum at 150 mA, 250 MHz transition frequency, TO-92 package, 625 mW dissipation, -55 to +150 °C. The complementary pairing is the selection point: the NPN counterpart of the 2N4403 PNP for push-pull, H-bridge and complementary switching stages. Selection advice: for a complementary pair order the 2N4403 (PNP) alongside this 2N4401 (NPN) — they share ratings for symmetric drive. The 625 mW dissipation limits continuous high-current use, so size the load or add a driver for power switching. Evidence: onsemi 2N4401 datasheet and distributor listings confirm NPN, 40 V, 600 mA, hFE 100, 250 MHz and TO-92. Match the full 2N4401 code. State quantity, packing and date-code requirements in your RFQ; we reconfirm the offered lot before quotation and reply within 24 hours.

BC546B is an onsemi NPN general-purpose transistor — 65 V collector-emitter voltage, 100 mA continuous collector current, DC current gain of 200 to 450 (B rank), 300 MHz transition frequency, TO-92 package, 500 mW dissipation, -55 to +150 °C. The 65 V rating is the selection point: the highest-voltage grade of the BC54x family for high-voltage preamplifier stages and driver circuits. Selection advice: the B suffix sets the gain rank — A is lower and C is higher, so match the full BC546B code to your gain requirement. The PNP complement is the BC556B in the same family for push-pull stages. Evidence: onsemi/NXP BC54x datasheet and distributor listings confirm NPN, 65 V, 100 mA, hFE 200 to 450 (B rank) and TO-92. Match the full BC546B code for gain rank. State quantity, packing and date-code requirements in your RFQ; we reconfirm the offered lot before quotation and reply within 24 hours.

BC547B is an onsemi NPN general-purpose transistor — 45 V collector-emitter voltage, 100 mA continuous collector current, DC current gain of 200 to 450 (B rank), 300 MHz transition frequency, TO-92 package, 500 mW dissipation, -55 to +150 °C. The 45 V rating with B gain rank is the selection point: the workhorse voltage grade of the BC54x family for general-purpose switching and amplification. Selection advice: the B suffix sets the gain rank — A is lower and C is higher, so match the full BC547B code to your gain requirement. The PNP complement is the BC557B in the same family for push-pull stages. Evidence: onsemi/NXP BC54x datasheet and distributor listings confirm NPN, 45 V, 100 mA, hFE 200 to 450 (B rank) and TO-92. Match the full BC547B code for gain rank. State quantity, packing and date-code requirements in your RFQ; we reconfirm the offered lot before quotation and reply within 24 hours.

BC548B is an onsemi NPN general-purpose transistor — 30 V collector-emitter voltage, 100 mA continuous collector current, DC current gain of 200 to 450 (B rank), 300 MHz transition frequency, TO-92 package, 500 mW dissipation, -55 to +150 °C. The 30 V B-rank combination is the selection point: the low-voltage, mid-gain member of the BC54x family for audio driver stages and general amplification where 30 V headroom suffices. Selection advice: the B suffix sets the gain rank — A is lower and C is higher, so match the full BC548B code to your gain requirement. The PNP complement is the BC558B in the same family; for higher voltage use the BC546/BC547 grades. Evidence: onsemi/Fairchild BC548 datasheet and distributor listings confirm NPN, 30 V, 100 mA, hFE 200-450 and TO-92. Match the full BC548B code for gain rank. State quantity, packing and date-code requirements in your RFQ; we reconfirm the offered lot before quotation and reply within 24 hours.

BC549C is an onsemi NPN low-noise general-purpose transistor — 30 V collector-emitter voltage, 100 mA continuous collector current, DC current gain of 420 to 800 (C rank), 300 MHz transition frequency, TO-92 package, 500 mW dissipation, -55 to +150 °C. The low-noise C rank is the selection point: 1.2-4 dB noise figure for audio preamplifier and low-noise input stages, with the highest gain rank of the family. Selection advice: the C suffix sets the gain rank — A is lower and B is middle, so match the full BC549C code to your gain requirement. The PNP complement is the BC559C in the same family. For higher voltage choose the BC546 family instead. Evidence: onsemi/NXP BC549 datasheet and distributor listings confirm NPN, 30 V, 100 mA, hFE 420-800 and TO-92. Match the full BC549C code for gain rank. State quantity, packing and date-code requirements in your RFQ; we reconfirm the offered lot before quotation and reply within 24 hours.

BC847B is a Nexperia NPN general-purpose transistor — 45 V, 100 mA, gain group B (hFE 200–450), SOT-23 (TO-236AB) package, 150 °C max junction. The gain group B is the selection point: the middle gain bin of the BC847 family (A: 110–220, B: 200–450, C: 420–800) — the default choice for small-signal switching and amplification where the gain bin matters for bias stability. Selection advice: Nexperia lists the BC847B as in production. Match the gain group on the BOM — substituting a BC847C changes the bias point of a designed stage. Its PNP complement is the BC857B for complementary stages. The BC847 is the 45 V member of the family — its siblings BC848 (30 V) and BC849 (30 V, low noise) are lower-voltage, not upgrades. Evidence: Nexperia data confirms in-production, 45 V, 100 mA, gain group B, SOT-23. Match the full BC847B code — the gain letter changes the part. State quantity, packing and date-code requirements in your RFQ; we reconfirm the offered lot before quotation and reply within 24 hours.

BC847C,215 is Nexperia’s highest-gain grade of the BC847 NPN general-purpose transistor — 45 V / 100 mA in SOT-23 — with DC current gain hFE 420–800 (minimum 420 at 2 mA, 5 V). The ‘C’ is the gain rank: A covers 110–220, B covers 200–450, and C covers 420–800; ‘,215’ denotes tape-and-reel packing of the same die. AEC-Q101 qualified, which makes the C grade a defensible pick for automotive-adjacent small-signal stages. Selection advice: BC847C is footprint- and pin-compatible with BC847A/B, but dropping a lower grade into a bias-sensitive amplifier stage shifts the operating point — re-check base bias when substituting grades. For pure switching the grade barely matters, and BC847B is usually cheaper and better stocked. Pair with the PNP complement BC857C for push-pull or complementary driver stages. Parameters trace to the manufacturer datasheet; state quantity, packing and date-code requirements in your RFQ — we reconfirm the offered lot before quotation and reply within 24 hours.

MMBT3904LT1G is an onsemi general-purpose NPN transistor in SOT-23, tape and reel — for small-signal switching and amplification: driver stages, level shifting and discrete logic. 40 V, 200 mA with 300 MHz transition frequency is the selection point: the classic jellybean NPN in the smallest common SMD package. Selection advice: the T1G suffix denotes tape and reel — for the PNP complement, the MMBT3906LT1G on this site is the mirror part. AEC-Q101 qualified, so it is usable in automotive-adjacent builds where a qualified jellybean is required. hFE 300 minimum. Parameters verified against distributor and manufacturer documentation. State quantity, packing and date-code requirements in your RFQ; we reconfirm the offered lot before quotation and reply within 24 hours.