onsemi

MMBT3904 - 40V NPN Small-Signal Transistor, 200mA | Multi-Source

N.º da peça: MMBT3904 ✓ Ativo

Em estoque Enviado em 1 a 3 dias úteis

40 V Vdss 200 mA Id SOT-23 (TO-236AB), 3 pins Package 300 MHz (typ, at VCE=20 V, IC=10 mA) Speed

A partir de $0.04 USD / unidade

MOQ: 1 |

Preço atualizado: 2026-10-04

Preços por volume

Qtd.	Preço unitário	Total
1	$0.13	$0,13
10	$0.11	$1,10
100	$0.08	$8,00
500	$0.06	$30,00
1.000	$0.05	$50,00
3.000	$0.04	$120,00

ℹ️ Todos os preços estão em USD

Ver datasheet (PDF) Ver alternativas

Quantidade

MMBT3904 Visão geral

The MMBT3904 is a 40 V NPN silicon bipolar junction transistor (BJT) in a 3-pin SOT-23 surface-mount package, rated for 200 mA continuous collector current and a 300 MHz transition frequency. It is offered as a generic industry-standard part number by multiple manufacturers including onsemi, Nexperia, Diodes Incorporated, and Fairchild Semiconductor, with each vendor publishing equivalent or near-equivalent specifications under the same MMBT3904 marking.

A small-signal BJT is a type of bipolar transistor optimized for low-current amplification and switching rather than power delivery. In the semiconductor taxonomy, the MMBT3904 sits under: BJT -> bipolar transistor -> discrete semiconductor. It functions as the NPN complement to the MMBT3906 (PNP) and is the surface-mount counterpart to the through-hole 2N3904, sharing the same die-level electrical targets but in a smaller SOT-23 footprint.

Key features include a 40 V collector-emitter breakdown (VCEO), 60 V collector-base breakdown (VCBO), a DC current gain (hFE) range of 100 to 300 at 10 mA, and a power dissipation of approximately 200 to 350 mW depending on board layout. The epitaxial planar die construction provides tight parametric distribution and the complementary MMBT3906 PNP enables push-pull output stages. Most datasheet revisions are lead-free, fully RoHS compliant, and several are AEC-Q101 qualified for automotive use.

Architecturally, the device is designed as a general-purpose amplifier and switch, with a useful dynamic range extending to 100 mA as a switch and 100 MHz as an amplifier. The SOT-23 package occupies roughly 6 mm² of board area and is the de-facto industry standard for low-power SMD transistors.

Typical applications include general-purpose switching circuits, signal amplification, interface logic level shifting, oscillator building blocks, driver stages for LEDs and small relays, and complementary push-pull pairs in audio output stages. Designers should select it whenever a low-cost, widely second-sourced NPN transistor is needed for non-critical analog or digital switching tasks.

When designing with the MMBT3904, observe the maximum collector dissipation (typically 200 mW on a minimal pad, up to 350 mW with the JEDEC 1 oz copper test board of 15 mm x 15 mm). For switching applications, include a base drive resistor to control saturation and improve turn-off time.

Alternativas drop-in para MMBT3904 — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.

Variantes desta série

Modelos da mesma série compatíveis como drop-in com MMBT3904 (mesmo formato e footprint) — diferindo em Package, Transition Frequency (fT), DC Current Gain (hFE), RoHS Status, Operating Temperature Range.

MMBT3904,215

Nexperia

Package: SOT-23 (TO-236AB)

Transition Frequency (fT): 300 MHz (minimum)

DC Current Gain (hFE): 100 to 300 (at IC = 10 mA, VCE = 1 V)

Comparar com MMBT3904 →

MMBT3904-AQ

Diotec Semiconductor

Package: SOT-23-3 (TO-236)

Transition Frequency (fT): 300 MHz (at VCE=20V, IC=10mA)

DC Current Gain (hFE): 100 to 300

Comparar com MMBT3904 →

MMBT3904LT1

onsemi

Package: SOT-23 (TO-236), 3-pin

Transition Frequency (fT): 300 MHz (min)

DC Current Gain (hFE): 100 to 300

Comparar com MMBT3904 →

Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:

MMBT3904LT1G

✅ Drop-In

📦 SOT-23

same SOT-23 footprint, same die family, AEC-Q101 qualified automotive grade, tape and reel packaging variant

📋 Alternativa de referência (fora do catálogo)

MMBT3904LT3G

✅ Drop-In

📦 SOT-23

same SOT-23 footprint, same die family, larger reel (10k units) packaging variant, halogen-free/BFR-free per FindIC

📋 Alternativa de referência (fora do catálogo)

SMMBT3904

✅ Drop-In

📦 SOT-23

same SOT-23 footprint, surface-mount variant from onsemi, identical 40V/200mA/300MHz electrical ratings

📋 Alternativa de referência (fora do catálogo)

MMBT3904,215

✅ Drop-In

Nexperia

📦 SOT-23 (TO-236AB)

NPN · SOT-23 (TO-236AB) · Surface Mount · 40 V · 60 V · 6 V · 200 mA · 250 mW

✓ Em estoque

$0.015 / unidade

Ver ficha técnica →

MMBT3904-13P

✅ Drop-In

📦 SOT-23

same SOT-23 footprint, epitaxial planar die, complementary PNP MMBT3906, lead-free and RoHS compliant, identical 40V/200mA ratings

📋 Alternativa de referência (fora do catálogo)

MMBT3904-TP

✅ Drop-In

📦 SOT-23

same SOT-23 footprint, 40V VCEO, 200mA IC, 300MHz fT, pin-to-pin compatible drop-in

📋 Alternativa de referência (fora do catálogo)

MMBT3904 Classificações máximas e características elétricas

Tipo de transistor	NPN
Encapsulamento	SOT-23 (TO-236AB), 3 pins
Tensão coletor-emissor (Vceo)	40 V
Tensão coletor-base (Vcbo)	60 V
Tensão emissor-base (Vebo)	6 V
Continuous Collector Current (IC)	200 mA
Power Dissipation (PD)	200 mW to 350 mW (board-dependent)
Frequência de transição (ft)	300 MHz (typ, at VCE=20 V, IC=10 mA)
DC Current Gain (hFE)	100 to 300 (at IC=10 mA, VCE=1.0 V)
Noise Figure	5 dB (max)
Faixa de temperatura de operação	-55C to +150C (junction)
Tipo de montagem	Surface Mount
Complementary PNP Part	MMBT3906
Lead-Free / RoHS	Yes (fully RoHS compliant per datasheet)
Automotive Grade (AEC-Q101)	Qualified by selected suppliers

Configuração de pinos do MMBT3904

Pino 1	BASE — Base control terminal
Pino 2	EMITTER — Emitter terminal (grounded in common-emitter configurations)
Pino 3	COLLECTOR — Collector terminal (load connection)

Aplicações típicas

MMBT3904 é adequado para 6 aplicaçãos: General-Purpose Switching Circuit, Signal Amplification Stage, Logic Level Shifter, Oscillator and Timer Building Block, LED Driver and Indicator Stage, Complementary Push-Pull Audio Output.

🔧

General-Purpose Switching Circuit

The MMBT3904's 40V VCEO, 200mA IC, and 300MHz fT make it ideal for general-purpose low-side switching applications such as driving LEDs, small relays, and logic-level shifters. Its 100-300 hFE range at 10mA provides ample base drive margin when interfaced from 3.3V or 5V microcontrollers via a series base resistor. The SOT-23 footprint enables dense PCB layouts in consumer electronics and IoT devices, while the multi-vendor second-source availability ensures supply chain resilience.

Recomendado

MMBT3906 (Complementary PNP for push-pull switching) 2N3904 (Through-hole equivalent for breadboarding)

🎧

Signal Amplification Stage

With a 300 MHz transition frequency and an hFE of 100 to 300 at 10 mA, the MMBT3904 functions well as a small-signal amplifier in the audio to RF range below 100 MHz. It is commonly deployed in pre-amplifier stages, IF buffers, and general-purpose analog gain blocks where cost per channel matters more than ultra-low noise. The complementary MMBT3906 enables matched differential or push-pull amplifier topologies for balanced signal paths.

Recomendado

MMBT3906 (Complementary PNP for differential/push-pull amplifier) BC847B (Alternative low-noise NPN amplifier)

🌐

Logic Level Shifter

The MMBT3904 is widely used as a single-transistor level shifter between 3.3V microcontrollers and 5V or 12V peripherals, leveraging its 40V VCEO to tolerate higher rail voltages. With a base resistor sized for the source logic high level and a pull-up on the collector, the circuit achieves fast edges suitable for GPIO, I2C, or UART bridging. The 200mA collector rating comfortably drives opto-couplers, small SSR coils, and indicator LEDs in interface cards.

Recomendado

MMBT3906 (PNP complement for bidirectional level shifting) 2N3904 (Through-hole equivalent for prototyping level shifters)

⏱️

Oscillator and Timer Building Block

The MMBT3904's 300MHz fT and predictable hFE characteristics make it a reliable active device for astable and monostable multivibrator circuits, RC oscillators, and 555-style timer replacements. Its fast switching response supports stable oscillation from sub-audio to several MHz, and the SOT-23 package keeps oscillator sections compact in hobby and educational designs. Designers should add base resistor bias networks to stabilize amplitude against temperature variation.

Recomendado

MMBT3906 (Complementary PNP for astable multivibrator) 2N3904 (Through-hole NPN for oscillator prototyping)

💡

LED Driver and Indicator Stage

The MMBT3904 efficiently drives indicator LEDs, optocouplers, and small seven-segment displays from logic-level inputs. At 200mA continuous collector current, it can sink or source a chain of indicator LEDs with proper base bias, and its 40V rating tolerates higher supply rails used in industrial HMI panels. The SOT-23 SMD package suits automated pick-and-place assembly for volume production of consumer and industrial control boards.

Recomendado

MMBT3906 (Complementary PNP for complementary LED driver) BC847B (Alternative NPN for LED multiplexing)

🎧

Complementary Push-Pull Audio Output

Paired with the MMBT3906 PNP, the MMBT3904 forms a Class-B push-pull output stage capable of delivering modest audio power into headphones or small speakers. The matched VCEO and hFE characteristics ensure symmetrical clipping and low crossover distortion in low-power audio buffer designs. Although not a high-fidelity audio transistor, it suffices for intercom, toy, and hobby audio applications where cost is critical.

Recomendado

MMBT3906 (Complementary PNP partner in push-pull output) 2N3904 (Through-hole NPN for breadboarded audio amp)

Resumo dos produtos recomendados

MMBT3906 Complementary PNP for push-pull switching Usado em: General-Purpose Switching Circuit, Signal Amplification Stage, Logic Level Shifter, Oscillator and Timer Building Block, LED Driver and Indicator Stage, Complementary Push-Pull Audio Output 2N3904 Through-hole equivalent for breadboarding Usado em: General-Purpose Switching Circuit, Logic Level Shifter, Oscillator and Timer Building Block, Complementary Push-Pull Audio Output BC847B Alternative low-noise NPN amplifier Usado em: Signal Amplification Stage, LED Driver and Indicator Stage

What is the MMBT3904 transistor?

The MMBT3904 is a 40 V NPN small-signal bipolar junction transistor (BJT) in a 3-pin SOT-23 surface-mount package, with a 200 mA continuous collector current rating and 300 MHz transition frequency. It is the surface-mount counterpart to the through-hole 2N3904 and is widely second-sourced by onsemi, Nexperia, Diodes Incorporated, and Fairchild Semiconductor under the same MMBT3904 part number with comparable specifications.

What is the maximum collector-emitter voltage of the MMBT3904?

The MMBT3904 has a VCEO rating of 40 V, meaning the collector-emitter junction can withstand up to 40 V with the base open. According to the manufacturer datasheet, VCBO is 60 V and VEBO is 6 V. These ratings are identical across onsemi, Nexperia, and Diodes Incorporated datasheet revisions for this part, ensuring drop-in compatibility across vendors.

How much current can the MMBT3904 handle?

The MMBT3904 is rated for 200 mA continuous collector current. The useful switching dynamic range extends to 100 mA per the manufacturer datasheet, and the amplifier dynamic range is specified to 100 MHz. Power dissipation is approximately 200 mW on a minimal PCB pad and up to 350 mW on the JEDEC-standard 15 mm x 15 mm 1 oz copper test board.

What is the pinout of the MMBT3904 in SOT-23?

The MMBT3904 SOT-23 pinout, viewed from the marked (top) side with pin 1 on the lower left, is: Pin 1 = Base, Pin 2 = Emitter, Pin 3 = Collector. The plastic package marking is typically "1A" (onsemi, Nexperia) or vendor-specific codes, and the pin assignment matches the industry-standard SOT-23 NPN outline used by all major second-source suppliers.

Is the MMBT3904 the same as the 2N3904?

The MMBT3904 is the surface-mount (SOT-23) version of the through-hole 2N3904 (TO-92). Both share the same core NPN silicon die targets: 40 V VCEO, 200 mA IC, and 300 MHz fT. The MMBT3904 is not pin-to-pin compatible with the 2N3904 because of the different package, but it is electrically equivalent for general-purpose amplifier and switching applications.

What is the complementary PNP transistor to the MMBT3904?

The MMBT3906 is the complementary PNP counterpart to the MMBT3904, sharing the same SOT-23 package and most electrical characteristics, but with reversed polarity (PNP). The MMBT3904/MMBT3906 pair is widely used in push-pull output stages, complementary amplifiers, and level shifter circuits where matched NPN/PNP behavior is required.

Where can I buy the MMBT3904 online?

The MMBT3904 is widely stocked at major distributors including DigiKey, Mouser, Arrow, and LCSC, as of 2026-10-05. Multi-vendor availability includes onsemi, Nexperia, Diodes Incorporated, and Good-Ark Semiconductor, giving engineers strong second-source flexibility. The DigiKey listing for the onsemi version ships same-day for orders placed before the cutoff.

What is the price of the MMBT3904?

As of 2026-10-05, the MMBT3904 unit price is approximately $0.13 at qty 1, dropping to roughly $0.05 at qty 1000 and $0.04 at qty 3000 in tape-and-reel packaging. Pricing varies slightly between onsemi, Nexperia, and Diodes Incorporated versions, but all sit in the same low-cost commodity band typical of JEDEC-registered general-purpose transistors.

What is the lead time for the MMBT3904?

As of 2026-10-05, the MMBT3904 is in stock and ships same-day from major distributors including DigiKey and Mouser, with no allocation or extended lead time reported. Because the part is second-sourced by at least four major vendors (onsemi, Nexperia, Diodes Incorporated, Fairchild Semiconductor), supply risk is minimal even during broader semiconductor shortages.

MMBT3904 vs BC847B - which is better for low-noise audio pre-amplifiers?

For low-noise audio pre-amplifiers, the MMBT3904 is generally preferred because the manufacturer datasheet specifies a tighter switching-test limits table and an hFE range of 100-300 at 10 mA, while the BC847B datasheet emphasizes general-purpose gain with a similar but slightly different hFE curve. According to the MMBT3904 vs BC847B comparison, both work, but model the base drive and saturation depth for your specific circuit.

When should I choose the MMBT3904 over the BC847B?

Choose the MMBT3904 when you need a North-American-second-sourced 40 V/200 mA NPN with well-documented switching-test parameters, AEC-Q101 automotive grade availability, and consistent SOT-23 pinout across onsemi, Nexperia, and Diodes Incorporated. Choose the BC847B when your design prefers a European-source NPN with slightly lower noise figure emphasis or when matching to BC847-series companion parts.

What is the best drop-in replacement for the MMBT3904?

The best drop-in replacements for the MMBT3904 are SMMBT3904, MMBT3904LT1, and MMBT3904LT3, all sharing the same SOT-23 footprint, 40 V VCEO rating, 200 mA IC rating, and 300 MHz fT specification. Cross-brand alternatives include the Nexperia MMBT3904,215 and the Diodes Incorporated MMBT3904, both pin-compatible drop-ins in the same SOT-23 (TO-236AB) package.

Where can I download the MMBT3904 datasheet PDF?

The MMBT3904 datasheet PDF can be downloaded from the onsemi product page at https://www.onsemi.com/pdf/datasheet/mmbt3904lt1-d.pdf. Equivalent datasheets are also published by Nexperia, Diodes Incorporated, and Fairchild Semiconductor, all containing the same core electrical specifications (40 V VCEO, 200 mA IC, 300 MHz fT) for this industry-standard part.

What are the key specifications of the MMBT3904 that engineers should know?

The key specifications of the MMBT3904 are: VCEO = 40 V, VCBO = 60 V, VEBO = 6 V, continuous IC = 200 mA, fT = 300 MHz (at VCE=20 V, IC=10 mA), hFE = 100 to 300 (at IC=10 mA, VCE=1.0 V), and PD = 200 mW to 350 mW depending on PCB copper area. These parameters are consistent across onsemi, Nexperia, Diodes Incorporated, and Fairchild Semiconductor datasheet revisions.

What is the best Nexperia equivalent for the MMBT3904?

The best Nexperia equivalent for the onsemi MMBT3904 is the Nexperia MMBT3904,215, which is a true drop-in alternative sharing the same SOT-23 (TO-236AB) package, 40 V VCEO rating, 200 mA IC rating, and 300 MHz transition frequency. Nexperia's MMBT3904,215 is also lead-free and fully RoHS compliant, making it a direct cross-brand substitute without any PCB footprint change.

Dados de referência de engenharia para MMBT3904 — comparação, orientação de projeto e informações de conformidade.

Guia de seleção

Choose the MMBT3904 when you need a low-cost, widely-second-sourced 40 V/200 mA NPN BJT in a SOT-23 package for general-purpose switching, level shifting, or small-signal amplification. It is the default choice when board area is constrained and the through-hole 2N3904 is too large. Choose the BC847B if your design prioritizes a European-source NPN with slightly lower noise figure or if you need to match a BC847-series companion part. Choose the MMBT3906 as the complementary PNP partner whenever push-pull, differential, or bidirectional level-shifter topologies are required.

Comparação com alternativas

Parâmetro	Este produto	MMBT3904LT1G	MMBT3904LT3G	SMMBT3904	MMBT3904,215	MMBT3904-13P	MMBT3904-TP
Brand	onsemi	onsemi	onsemi	onsemi	Nexperia	Diodes Incorporated	Micro Commercial Components
Package	SOT-23	SOT-23 - same	SOT-23 - same	SOT-23 - same	SOT-23 (TO-236AB) - same	SOT-23 - same	SOT-23 - same
Transistor Type	NPN	NPN	NPN	NPN	NPN	NPN	NPN
VCEO (V)	40 V	40 V	40 V	40 V	40 V	40 V	40 V
VCBO (V)	60 V	60 V	60 V	60 V	60 V	60 V	60 V
Continuous IC (mA)	200 mA	200 mA	200 mA	200 mA	200 mA	200 mA	200 mA
Power Dissipation (mW)	200-350 mW	200-350 mW	200-350 mW	200-350 mW	250 mW	200-350 mW	200-350 mW
Transition Frequency fT (MHz)	300 MHz	300 MHz	300 MHz	300 MHz	300 MHz	300 MHz	300 MHz
hFE Range (at 10 mA)	100 to 300	100 to 300	100 to 300	100 to 300	100 to 300	100 to 300	100 to 300
RoHS / Lead-Free	Yes	Yes	Yes (Halogen/BFR-free)	Yes	Yes	Yes	Yes

Principais diferenciais

Wider VCBO headroom than the BC847B (vs BC847B)
Higher continuous collector current than the BC847B (vs BC847B)
Multi-vendor second-source availability (vs Vendor-locked equivalents)

Notas de projeto

Estimated: on a JEDEC-standard 15 mm x 15 mm 1 oz copper test pad, the MMBT3904 dissipates up to 350 mW; on a minimal SOT-23 land pattern, this drops to approximately 200 mW. For continuous 200 mA loads at elevated ambient temperature, ensure PCB copper area supports the thermal path or use multiple transistors in parallel. Refer to JESD22-A114 and JESD22-A115 thermal test methods per the manufacturer datasheet.

Do not exceed VCEO = 40 V, VCBO = 60 V, or VEBO = 6 V. For inductive loads such as relays or small solenoids, place a flyback diode across the coil to protect the collector from kickback voltage. When driving the base directly from a 3.3 V or 5 V microcontroller GPIO, always include a series base resistor to limit base current and avoid saturation-induced storage time delays in switching applications.

Use a SOT-23 land pattern per IPC-7351 with thermal pad copper tied to the collector pin (pin 3). For switching applications above 50 mA or frequencies above 10 MHz, keep the base trace short and place the base resistor within 5 mm of the base pin. Star-ground the emitter return to minimize common-emitter gain variations in amplifier topologies.

Informações de conformidade

RoHS

Compliant

REACH

Compliant

AEC-Q100

Not Applicable

Sem chumbo

Yes

Sem halogênios

Yes

Minerais de conflito

Compliant

Fully RoHS compliant and lead-free per manufacturer datasheets. Selected supplier versions are AEC-Q101 qualified for automotive; consult individual vendor datasheets. Halogen-free/BFR-free per the onsemi MMBT3904LT3G datasheet. Thermal test methods referenced per JEDEC JESD22-A114 and JESD22-A115.

Dados verificados em: 2026-10-05 — dados verificados e curados pela equipe de engenharia de componentes da XAIPART

Fontes: Distributor, Manufacturer Datasheet, Manufacturer Datasheet, Manufacturer Datasheet, Manufacturer Datasheet, Distributor, Manufacturer Datasheet, Manufacturer Product Page, Distributor, Manufacturer Product Page, Manufacturer Product Page

Buscas relacionadas

MMBT3904 MMBT3904 datasheet MMBT3904 SOT-23 NPN transistor MMBT3904 equivalent MMBT3904 pinout MMBT3904 vs BC847B MMBT3904 drop-in replacement 40V 200mA NPN SOT-23 transistor MMBT3904 buy online MMBT3904 price what is MMBT3904 used for MMBT3904 complementary PNP MMBT3906

Componentes & termos relacionados

MMBT3904 onsemi Nexperia Diodes Incorporated Fairchild Semiconductor MMBT3904LT1G MMBT3904LT3G SMMBT3904 MMBT3904,215 MMBT3904-13P MMBT3904-TP MMBT3906 BC847B 2N3904 NPN bipolar junction transistor BJT bipolar transistor discrete semiconductor SOT-23 TO-236AB small-signal transistor surface mount RoHS AEC-Q101 JEDEC JESD22-A114 JEDEC JESD22-A115 complementary push-pull level shifter LED driver audio amplifier 300 MHz transition frequency 200 mA collector current 40 V VCEO 60 V VCBO 100-300 hFE epitaxial planar die IPC-7351