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Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Single Bipolar Transistors

onsemi MMBT3906WT1

Name: MMBT3906WT1
Brand: onsemi
SKU: MMBT3906WT1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MMBT3906WT1

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: -

Datasheet:: MMBT3906WT1.pdf

Description:: TRANS SS GP PNP 40V SOT323

Quantity:: RFQ Add To RFQ list

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Product details

Overview

MMBT3906WT1 from onsemi is a PNP general-purpose silicon bipolar junction transistor (BJT) in SOT-323 (SC-70) package, rated for −40 V V_CEO, −200 mA I_C, and 150 mW power dissipation. It delivers DC current gain (h_FE) of 60–300 at I_C = −10 mA, V_CE = −1.0 V, and exhibits f_T = 250 MHz for RF-capable switching and amplification. It is widely used in low-power logic-level inversion, LED driver stages, and signal conditioning circuits in portable electronics.

For engineers reviewing the MMBT3906WT1 datasheet, pinout, applications, or equivalent options, this page provides verified electrical parameters, validated SOT-323 terminal mapping, confirmed PNP switching performance metrics (t_d/t_r/t_s/t_f), thermal resistance (R_θJA = 833°C/W), and RoHS-compliant packaging details - all specific to the MMBT3906WT1G variant.

Technical Context

The MMBT3906WT1 operates as a discrete PNP BJT with fixed emitter-base and collector-base junctions optimized for linear amplification and saturated switching. Its −40 V V_CEO and −5.0 V V_EBO ratings support operation in negative-rail bias configurations up to −30 V, while its 250 MHz f_T enables use in audio-frequency amplifiers and low-speed digital interfaces.

Thermal design is constrained by R_θJA = 833°C/W on FR4 PCBs with minimum footprint, limiting continuous I_C to −200 mA only at T_A ≤ 25°C. The device's −0.25 V V_CE(sat) at I_C = −10 mA / I_B = −1.0 mA ensures efficient low-voltage switching in battery-powered systems.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−40 Vdc: Maximum reverse-biased collector-emitter voltage before breakdown; defines safe operating range in PNP common-emitter switch configurations.
I_C	−200 mAdc: Continuous collector current limit; sets maximum load drive capability in saturated switching applications.
P_D	150 mW: Total device dissipation at T_A = 25°C; determines thermal derating slope (1.2 mW/°C above 25°C) on standard FR4 layout.
h_FE	60–300: DC current gain range at I_C = −10 mA, V_CE = −1.0 V; enables predictable base drive sizing for gain-stable amplification or switching.
f_T	250 MHz: Current-gain bandwidth product at I_C = −10 mA, V_CE = −20 V; supports audio-band amplification and sub-100 MHz digital signal routing.
V_CE(sat)	−0.25 Vdc (max) at I_C = −10 mA, I_B = −1.0 mA: Low saturation voltage minimizes power loss and heat generation in high-duty-cycle switching.
R_θJA	833 °C/W: Junction-to-ambient thermal resistance on FR4; requires careful PCB copper area planning to maintain T_J < 150°C under load.

Pinout & Package

The MMBT3906WT1 is housed in the SC-70/SOT-323 plastic surface-mount package (Case 419, Style 3), measuring 2.2 mm × 2.2 mm × 0.9 mm, with gull-wing leads and Pb-free finish. Pin 1 is Base, Pin 2 is Emitter, Pin 3 is Collector - verified per onsemi mechanical drawing 98ASB42819B and marking diagram.

Pin/Terminal	Circuit Role	Design Meaning
1 - Base	Control electrode	Receives forward-biased current to turn on PNP conduction; requires negative voltage relative to emitter for activation.
2 - Emitter	Current source terminal	Connected to higher potential rail (e.g., V_CC) in common-emitter configuration; carries full load current.
3 - Collector	Output/current sink terminal	Drains current to lower-potential node (e.g., ground or signal return); voltage swing limited to −40 V relative to emitter.

Key Features

Feature	Design Value
Pb-free, Halogen-free, RoHS-compliant	Meets global environmental regulations without compromising solderability or reliability on reflow assembly lines.
AEC-Q101 qualified (S-prefix variants)	Validated for automotive-grade temperature cycling, humidity, and mechanical stress - applicable to SMMBT3906WT1G but not standard MMBT3906WT1G.
Low V_CE(sat) (−0.25 V max)	Reduces conduction losses in battery-operated LED drivers and level translators, improving system efficiency at 3.3 V or 5 V rails.
High f_T (250 MHz)	Supports clean edge transitions in 10–50 MHz clock buffering and audio preamplifier stages without phase distortion.
Small-footprint SOT-323 package	Enables high-density PCB layouts in space-constrained IoT sensors, wearables, and portable medical devices.

Applications

LED Driver Stage	Logic-Level Inverter
Use Scenario: Driving 20 mA indicator LEDs from 3.3 V microcontroller GPIO pins with active-low control. IC Role / Device Role / Timing Role: PNP switch sinking current from V_CC through LED to GPIO (low = ON). Use Value: −0.25 V V_CE(sat) ensures >3.0 V forward drop across LED at full brightness, maximizing luminous output.	Use Scenario: Converting TTL/CMOS logic HIGH (3.3 V) to LOW (0 V) for interfacing with legacy 5 V systems. IC Role / Device Role / Timing Role: Single-transistor inverter with resistor bias network providing rail-to-rail output swing. Use Value: 250 MHz f_T and 35 ns t_r/t_f support clean inversion of signals up to 10 MHz without edge rounding.
Load Switch for Negative Rail	Audio Preamp Input Stage
Use Scenario: Enabling/disabling −12 V analog circuitry using a 0 V/3.3 V control signal. IC Role / Device Role / Timing Role: High-side PNP switch controlling current flow from negative supply to load. Use Value: −40 V V_CEO and −40 V V_CBO ensure safe operation with 12 V headroom, preventing breakdown during transients.	Use Scenario: Amplifying low-level microphone signals (10 mVpp) in portable voice recorders. IC Role / Device Role / Timing Role: Common-emitter small-signal amplifier with 10 kΩ collector load and emitter degeneration. Use Value: 4.0 dB noise figure at 1 kHz and 100 Ω source impedance preserves SNR in battery-powered audio front-ends.

LED Driver Stage

Logic-Level Inverter

Use Scenario: Driving 20 mA indicator LEDs from 3.3 V microcontroller GPIO pins with active-low control.

IC Role / Device Role / Timing Role: PNP switch sinking current from V_CC through LED to GPIO (low = ON).

Use Value: −0.25 V V_CE(sat) ensures >3.0 V forward drop across LED at full brightness, maximizing luminous output.

Use Scenario: Converting TTL/CMOS logic HIGH (3.3 V) to LOW (0 V) for interfacing with legacy 5 V systems.

IC Role / Device Role / Timing Role: Single-transistor inverter with resistor bias network providing rail-to-rail output swing.

Use Value: 250 MHz f_T and 35 ns t_r/t_f support clean inversion of signals up to 10 MHz without edge rounding.

Load Switch for Negative Rail

Audio Preamp Input Stage

Use Scenario: Enabling/disabling −12 V analog circuitry using a 0 V/3.3 V control signal.

IC Role / Device Role / Timing Role: High-side PNP switch controlling current flow from negative supply to load.

Use Value: −40 V V_CEO and −40 V V_CBO ensure safe operation with 12 V headroom, preventing breakdown during transients.

Use Scenario: Amplifying low-level microphone signals (10 mVpp) in portable voice recorders.

IC Role / Device Role / Timing Role: Common-emitter small-signal amplifier with 10 kΩ collector load and emitter degeneration.

Use Value: 4.0 dB noise figure at 1 kHz and 100 Ω source impedance preserves SNR in battery-powered audio front-ends.

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP general-purpose transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MMBT3906LT1G	SOT-23 package (larger footprint, 3.0 mm × 1.4 mm), identical electrical specs, same onsemi die.	Requires PCB layout change; better thermal dissipation (R_θJA ≈ 400°C/W) but occupies ~2.5× more board area.	Select when thermal margin is critical and board space allows SOT-23; avoid if miniaturization is mandatory.
PN2907A	TO-92 through-hole package, −60 V V_CEO, −600 mA I_C, slower f_T (~100 MHz), higher V_CE(sat) (−0.5 V).	Not surface-mount compatible; suited for prototyping or high-voltage, high-current legacy designs where SMT is impractical.	Choose only for hand-soldered prototypes or repair of through-hole assemblies; not a drop-in replacement.

Compared with MMBT3906WT1, MMBT3906LT1G offers superior thermal performance in larger SMT footprints, while PN2907A trades miniaturization for higher voltage/current headroom and through-hole compatibility - neither is pin-compatible, requiring layout or assembly process changes.

Availability

MMBT3906WT1 is available at Aetrix Electronics and suitable for LED driver stages, logic-level inverters, negative-rail load switches, and audio preamplifier input stages requiring stable component supply across industrial, consumer, and medical OEM programs.

Supply support for MMBT3906WT1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and IoT markets.

The MMBT3906WT1 belongs to onsemi's general-purpose transistor family designed for cost-sensitive, high-volume applications demanding reliable low-power amplification and switching in compact SMT packages.

FAQ

What is the maximum collector-emitter voltage rating for the MMBT3906WT1?

The MMBT3906WT1 has a maximum collector-emitter voltage (V_CEO) rating of −40 Vdc. This specifies the highest reverse-biased voltage that can be applied between collector and emitter with the base open before breakdown occurs. Exceeding this value risks permanent damage, especially under transient conditions or elevated temperatures.

Is the MMBT3906WT1 RoHS-compliant and lead-free?

Yes, the MMBT3906WT1G variant is explicitly marked as Pb-free, halogen-free, and RoHS-compliant per onsemi documentation. The "G" suffix denotes green packaging, and the device meets EU Directive 2011/65/EU requirements without exemptions. Always verify reel markings match MMBT3906WT1G for compliance assurance.

What is the typical DC current gain (h_FE) of the MMBT3906WT1 at 10 mA collector current?

The MMBT3906WT1 exhibits a DC current gain (h_FE) ranging from 60 to 300 when tested at I_C = −10 mA and V_CE = −1.0 V, per the official onsemi datasheet. This wide range reflects process variation; design margins should assume h_FE ≥ 60 for worst-case base drive calculations in switching applications.

Can the MMBT3906WT1 be used in audio amplifier circuits?

Yes, the MMBT3906WT1 is suitable for low-noise audio preamplifier stages due to its 4.0 dB noise figure at 1 kHz and 100 Ω source impedance, combined with 250 MHz f_T and stable h_FE. It performs well in common-emitter configurations for microphone signal boosting, provided biasing accounts for its PNP polarity and thermal limits.

What is the thermal resistance (R_θJA) of the MMBT3906WT1 on a standard FR4 PCB?

The MMBT3906WT1 has a thermal resistance (R_θJA) of 833°C/W when mounted on an FR4 printed circuit board using the minimum recommended footprint per onsemi's thermal characterization note. This value assumes no additional copper pour or thermal vias; adding 100 mm² of 2-oz copper on the collector pad reduces R_θJA by ~200°C/W.

MMBT3906WT1 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: *

Package/Case:: -

Packaging:: Cut Tape (CT)

Product Status:: Obsolete

Transistor Type:: -

Current - Collector (Ic) (Max):: -

Voltage - Collector Emitter Breakdown (Max):: -

Vce Saturation (Max) @ Ib, Ic:: -

Current - Collector Cutoff (Max):: -

DC Current Gain (hFE) (Min) @ Ic, Vce:: -

Power - Max:: -

Frequency - Transition:: -

Operating Temperature:: -

Grade:: -

Qualification:: -

Mounting Type:: -

Supplier Device Package:: -

MMBT3906WT1 FAQ

1.How can I place an order for MMBT3906WT1 through Aetrix?

Please submit a Request for Quotation (RFQ) for MMBT3906WT1 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for MMBT3906WT1 reliable?

The price and inventory of MMBT3906WT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBT3906WT1 is usually 5 days.

3.What payment methods are accepted for MMBT3906WT1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBT3906WT1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MMBT3906WT1?

MMBT3906WT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MMBT3906WT1 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for MMBT3906WT1?

For technical support, including MMBT3906WT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBT3906WT1 requirements.

6.How does Aetrix verify that MMBT3906WT1 is sourced from the original manufacturer or authorized distributors?

All MMBT3906WT1 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MMBT3906WT1 meets industry standards.

7.What is the process for return or replacement of MMBT3906WT1?

All MMBT3906WT1 units undergo pre-shipment inspection (PSI). If there is an issue with MMBT3906WT1, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The MMBT3906WT1 part is unused and in its original packaging.

Return procedure for MMBT3906WT1:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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