MMBT3904,215 - 40V NPN Switching Transistor | Nexperia SOT-23
部品番号: MMBT3904,215 ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $0.04 | $0.04 |
| 10 | $0.035 | $0.35 |
| 100 | $0.028 | $2.80 |
| 500 | $0.022 | $11.00 |
| 1,000 | $0.018 | $18.00 |
| 3,000 | $0.015 | $45.00 |
MMBT3904,215 概要
A bipolar junction transistor (BJT) is a three-terminal semiconductor device in which a small base current controls a much larger collector current, enabling amplification and switching functions. The NPN variant draws electrons from emitter to collector, with the base-emitter junction forward biased and the base-collector junction reverse biased in the active region. In the broader taxonomy, the BJT sits below the power-management hierarchy as a discrete semiconductor alongside MOSFETs, IGBTs, and Darlingtons, while the SOT-23 package belongs to the small-outline surface-mount family used when board area is constrained.
Key specifications of the MMBT3904,215 include a collector-emitter breakdown voltage (VCEO) of 40 V, collector-base voltage (VCBO) of 60 V, emitter-base voltage (VEBO) of 6 V, DC current gain (hFE) between 100 and 300 at 10 mA, and a noise figure below 5 dB. The three-pin SOT-23 footprint enables fully automated assembly, while the 300 MHz transition frequency (fT) supports switching speeds into the low-nanosecond range and RF amplifier designs up to UHF.
Architecturally, the MMBT3904 uses an epitaxial planar NPN structure with gold-doped die attach for long-term stability and is complementary to the PNP MMBT3906 in the same package. Its high gain-bandwidth product and low saturation voltage (around 200 mV at 10 mA) make it equally suitable for linear amplification and saturated switching service.
Typical applications include inverter and interface circuits, general-purpose switching in portable and battery-powered devices, DC-DC converter driver stages, sensor signal conditioning, and low-power audio pre-amplifiers. The SOT-23 footprint is compatible with high-density PCB layouts where a TO-92 2N3904 would be impractical.
Designers should observe the 250 mW power-dissipation limit at 25 °C, derate to zero at 150 °C, and ensure base current stays within the safe operating area to prevent thermal runaway. For high-volume production, the wide cross-vendor second-source availability of MMBT3904 parts provides strong supply-chain resilience.
This page synthesizes distributor pricing, drop-in second-source alternatives from verified cross-reference data, and practical design notes not consolidated in the manufacturer datasheet alone, supporting both component engineers and procurement specialists.
ドロップイン代替品: MMBT3904,215 — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
このシリーズのバリエーション
同一シリーズでドロップイン互換のモデル: MMBT3904,215 （同一形状・フットプリント） — 相違点: DC Current Gain (hFE), Operating Temperature Range, Transition Frequency (fT), Collector-Base Voltage (VCBO), Transistor Type.
クイック比較ツール — 並列比較する代替部品を選択:
MMBT3904
✅ ドロップイン✓ 在庫あり
$0.04 / 個
データシートを見る →MMBT3904,235
✅ ドロップイン📋 参考代替品（カタログ未掲載）
PMMBT3904
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MMBT3904LT1G
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MMBT3904LT3G
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MMBT3904-7-F
✅ ドロップイン✓ 在庫あり
$0.04 / 個
データシートを見る →MMBT3904,215 最大定格＆電気的特性
| トランジスタタイプ | NPN |
| パッケージ | SOT-23 (TO-236AB) |
| 実装タイプ | Surface Mount |
| コレクタ-エミッタ間電圧（Vceo） | 40 V |
| コレクタ-ベース間電圧（Vcbo） | 60 V |
| エミッタ-ベース間電圧（Vebo） | 6 V |
| Continuous Collector Current (IC) | 200 mA |
| Power Dissipation (Pd) | 250 mW |
| 遷移周波数（ft） | 300 MHz (minimum) |
| DC Current Gain (hFE) | 100 to 300 (at IC = 10 mA, VCE = 1 V) |
| コレクタ-エミッタ間飽和電圧（Vce(sat)） | 200 mV (typical at IC = 10 mA) |
| Noise Figure (NF) | 5 dB (maximum) |
| 動作温度範囲 | -65 °C to +150 °C |
| ピン数 | 3 |
| PNP Complement | MMBT3906 |
| RoHS ステータス | Compliant |
MMBT3904,215 ピン構成
| ピン 1 | Base — Control terminal - small base current (IB) controls the much larger collector current (IC); bias via resistor divider from supply |
| ピン 2 | Emitter — Current source terminal - electrons are emitted from this terminal into the base region; typically tied to ground (NPN) through emitter degeneration resistor |
| ピン 3 | Collector — Current sink terminal - main current path between collector and emitter when forward active; connect to load through pull-up resistor |
主な用途
MMBT3904,215 の用途: 6 件s: General-Purpose Switching Circuits, Inverter and Interface Logic, Audio Preamplifier Stages, RF Amplifier and Oscillator Circuits, Sensor Signal Conditioning, DC-DC Converter Driver Stage.
General-Purpose Switching Circuits
The Nexperia MMBT3904,215 is a workhorse NPN switch in low-current digital and analog circuits thanks to its 40 V VCEO and 200 mA continuous collector current in a compact SOT-23 footprint. With hFE between 100 and 300 at 10 mA and a VCE(sat) of roughly 200 mV, it cleanly handles LED drivers, relay coil drivers, and logic-level interface tasks. Placed between a microcontroller GPIO and a 12 V coil load, it requires only 1 mA of base drive for full saturation; unlike a MOSFET it needs no gate-charge current and operates directly from 3.3 V logic. The 300 MHz fT also keeps switching times comfortably in the low-nanosecond range for pulse-shaping and pulse-generation circuits.
おすすめ
Inverter and Interface Logic
The MMBT3904,215 is widely used in single-transistor inverter and level-shifter circuits that interface low-voltage logic to higher-voltage buses, where its 40 V VCEO safely tolerates 12 V and 24 V rails. With 100-300 hFE it amplifies microamp-level base currents into milliamp-level collector currents, allowing a 3.3 V microcontroller pin to switch a 12 V load. A typical common-emitter inverter uses a 10 kΩ base resistor and 10 kΩ collector pull-up; the MMBT3904 turns on within 50 ns of base drive. Compared with a logic-level MOSFET, it draws slightly more quiescent current but eliminates the gate-driver overhead.
おすすめ
Audio Preamplifier Stages
In small-signal audio preamplifier and buffer applications, the MMBT3904,215 delivers clean amplification thanks to its noise figure below 5 dB and DC current gain of 100-300. With 300 MHz transition frequency it preserves audio bandwidth well beyond the 20 kHz audible range. A typical common-emitter mic preamp uses 47 kΩ base bias and 1 kΩ emitter resistor; the MMBT3904 produces 30-40 dB voltage gain with low harmonic distortion. Unlike op-amp ICs it provides single-supply operation down to 3 V and adds only microamperes of quiescent current, suiting battery-powered audio gear.
おすすめ
RF Amplifier and Oscillator Circuits
The MMBT3904,215's 300 MHz transition frequency makes it a viable RF amplifier and oscillator transistor up to the lower UHF range, useful in 27 MHz, 49 MHz, and 433 MHz ISM-band front ends. Its low collector-base capacitance and 200 mW dissipation support common-base and common-emitter RF amplifiers with neutralization. In a typical Colpitts oscillator the MMBT3904 sustains oscillation above 100 MHz with a single 5 V rail; in RF mixers its low VCE(sat) and matched hFE keep conversion gain predictable. For higher frequencies or higher power, upgrade to a dedicated RF BJT such as the BFR520.
おすすめ
Sensor Signal Conditioning
Sensor signal-conditioning front-ends benefit from the MMBT3904,215's low noise figure and predictable hFE for amplifying low-level analog signals from thermistors, photodiodes, and Hall sensors. Its 40 V rating allows operation from industrial 24 V rails with adequate headroom. A typical transimpedance amplifier with an MMBT3904 converts a photodiode current into a usable voltage with 60 dB gain and bandwidth exceeding 1 MHz. Compared with op-amp signal chains, a single-transistor front-end reduces quiescent current to the microampere range and tolerates wider supply-voltage variation.
おすすめ
DC-DC Converter Driver Stage
The MMBT3904,215 is used as a low-side NPN driver for small DC-DC converters and charge-pump circuits, where its 40 V VCEO and 200 mA rating handle auxiliary supply rails up to 24 V. With hFE of 100-300 it can drive a power MOSFET's gate directly from a logic-level PWM source through a base resistor, eliminating the need for a dedicated gate-driver IC. Its 300 MHz fT supports switching frequencies above 1 MHz in non-isolated buck regulators. For higher-current outputs, cascade a Darlington pair such as the MMBT6427 or step up to a dedicated MOSFET driver.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: MMBT3904,215 — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | MMBT3904 | PMMBT3904 | MMBT3904LT1G | MMBT3904LT3G | MMBT3904-7-F |
|---|---|---|---|---|---|---|
| Brand | Nexperia | Nexperia | Nexperia | onsemi | onsemi | Diodes Incorporated |
| Package | SOT-23 (TO-236AB) | SOT-23 (TO-236AB) - identical | SOT-23 (TO-236AB) - identical | SOT-23 (TO-236AB) - identical | SOT-23 (TO-236AB) - identical | SOT-23 (TO-236AB) - identical |
| Transistor Type / Pinout | NPN, B-E-C (SOT-23) | NPN, B-E-C - identical | NPN, B-E-C - identical | NPN, B-E-C - identical | NPN, B-E-C - identical | NPN, B-E-C - identical |
| VCEO | 40 V | 40 V | 40 V | 40 V | 40 V | 40 V |
| Continuous Collector Current (IC) | 200 mA | 200 mA | 200 mA | 200 mA | 200 mA | 200 mA |
| Power Dissipation (Pd) | 250 mW | 250 mW | 250 mW | 250 mW | 250 mW | 250 mW |
| Transition Frequency (fT) | 300 MHz (min) | 300 MHz (min) | 300 MHz (min) | 300 MHz (min) | 300 MHz (min) | 300 MHz (min) |
| DC Current Gain (hFE) | 100 to 300 | 100 to 300 | 100 to 300 | 100 to 300 | 100 to 300 | 100 to 300 |
主な差別化要因
- Wide multi-vendor second-source availability with identical 40 V / 200 mA / 300 MHz envelope （vs MMBT3904LT1G (onsemi))
- Compact SOT-23 (TO-236AB) surface-mount footprint saves PCB area vs TO-92 alternatives （vs 2N3904 (TO-92 through-hole))
- Lowest unit cost in the 40 V NPN SOT-23 family with Nexperia automotive-grade pedigree （vs MMBT2222A (higher-current NPN))
設計ノート
The MMBT3904,215 is rated for 250 mW power dissipation at 25 °C ambient with linear derating to zero at 150 °C. In SOT-23 with typical theta-JA of 500 °C/W, designers should not exceed roughly 250 mW or expect the junction temperature to climb above 125 °C at full rating. Estimated: at VCE=10 V and IC=20 mA the dissipation is 200 mW - permissible but with margin to spare. For continuous operation above 150 mW, copper pours on the collector pad act as a heatsink and should be sized to a minimum of 100 mm². Avoid placing the transistor next to heat sources such as regulators or power inductors.
In SOT-23 the collector pad (pin 3) is the largest thermal and electrical node, so it should be tied to a copper pour of at least 50 mm² for both heat spreading and ground reference. The base and emitter pads should be routed with short traces to minimize parasitic inductance, especially in RF or fast-switching circuits above 100 MHz. Place base-bias resistor dividers within 3 mm of the base pad to prevent coupling from adjacent switching nodes. Use a ground plane on the opposite PCB side and stitch the emitter pad to ground with multiple vias.
Do not exceed VCEO=40 V on the collector or the breakdown voltage will be exceeded and the transistor will fail - in 24 V industrial rails stay under 36 V at the collector. Always include a base resistor (typically 10 kΩ to 100 kΩ) to limit base current; without it, a stray logic-high level can drive the base hard into saturation and over-dissipate the part. The PNP complement MMBT3906 has the B-C-E SOT-23 pinout convention reversed - never substitute one for the other without re-checking pin 1. For switching inductive loads, always add a flyback diode across the load because the MMBT3904 has no internal avalanche rating for inductive kickback.
At switching speeds above 100 MHz the MMBT3904's collector-base capacitance (typically 4 pF) starts to load the previous stage and reduce gain. For pulse-shaping circuits use a base-stopper resistor of 100 Ω to 1 kΩ to dampen parasitic oscillation, especially when driving capacitive loads. In RF amplifiers, add a ferrite bead or small inductor in series with the collector supply pin to isolate the DC rail from RF feedback. Common-base configurations reduce the Miller effect and are preferred above 200 MHz.
コンプライアンス情報
RoHS and REACH compliant per Nexperia product page; lead-free matte-tin plating. Not specifically AEC-Q100 qualified; for AEC-Q100 qualified NPN transistors in SOT-23, consider Nexperia's automotive-grade process variants. Conflict-minerals declaration compliant per Nexperia's published CMRT.
