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

Diodes Incorporated MMBT4126-7-F

Name: MMBT4126-7-F
Brand: Diodes Incorporated
SKU: MMBT4126-7-F
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MMBT4126-7-F

Manufacturer:: Diodes Incorporated

Category:: Single Bipolar Transistors

Package:: TO-236-3, SC-59, SOT-23-3

Datasheet:: MMBT4126-7-F.pdf

Description:: TRANS PNP 25V 0.2A SOT-23-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

MMBT4126-7-F from Diodes Incorporated is a PNP small-signal transistor in SOT23 package, rated for -25 V V_CEO, -200 mA I_C, and 200 mW power dissipation, with h_FE = 120–360 at I_C = -2 mA, used in medium-power switching and amplification circuits in industrial control and sensor interface modules.

For engineers reviewing the MMBT4126-7-F datasheet, MMBT4126-7-F pinout, MMBT4126-7-F application, or MMBT4126-7-F equivalent, this page delivers verified electrical specs, SOT23 terminal mapping, AEC-Q101 qualification status, thermal derating behavior, and direct replacement guidance versus MMBT3906-7-F.

Technical Context

This PNP bipolar junction transistor employs epitaxial planar die construction for stable gain and low leakage, supporting linear amplification (h_FE up to 480 at 2 mA) and saturated switching (V_CE(SAT) ≤ -0.4 V at -50 mA/-5 mA). Its f_T of 250 MHz enables RF preamp use up to low-VHF bands.

Designed for automotive-grade reliability, it meets AEC-Q101 stress testing requirements and features halogen/antimony-free "Green" molding compound (UL 94V-0), matte tin-plated leads, and moisture sensitivity level 1 - enabling reflow compatibility without baking.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	-25 V - Maximum safe collector-emitter voltage before breakdown under open-base conditions
I_C	-200 mA - Continuous DC collector current limit; derates linearly above +25°C ambient
P_D	200 mW - Max steady-state power on FR-4 PCB with 1 oz copper; R_θJA = 625°C/W
h_FE	120–360 - DC current gain range at I_C = -2 mA, V_CE = -1 V; supports bias stability in amplifier stages
f_T	250 MHz - Transition frequency at V_CE = -20 V, I_C = -10 mA; usable in low-noise RF front-ends
NF	4.0 dB - Noise figure at V_CE = -5 V, I_C = -100 µA, R_S = 1 kΩ, 1 kHz; suitable for audio preamplifiers

Pinout & Package

Package: SOT23 - surface-mount plastic case, 0.008 g weight, UL 94V-0 rated, JEDEC-compliant footprint with 0.915 mm lead pitch and 2.40 mm body length.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	E	Current source terminal in PNP operation; connects to higher potential node in switching or bias networks
2 (Base)	B	Control input; requires negative base current relative to emitter to turn on device
3 (Collector)	C	Current sink terminal; ties to load or supply rail depending on circuit topology (e.g., high-side switch)

Key Features

Feature	Design Value
AEC-Q101 qualified	Validated for automotive electronics per stress test requirements (HTOL, TC, HAST, etc.)
Halogen & antimony free	Meets "Green" definition: Br < 900 ppm, Cl < 900 ppm (Br+Cl < 1500 ppm), Sb < 1000 ppm
Low V_CE(SAT)	-0.4 V at -50 mA/-5 mA - minimizes conduction loss in digital logic-level switching
ESD robustness	HBM 4 kV / MM 400 V - withstands handling and board-level ESD events without parameter shift

Applications

Industrial Sensor Interface

Automotive Body Control Module

Use Scenario: Amplifying low-level analog signals from temperature or pressure sensors before ADC sampling.

IC Role / Device Role / Timing Role: PNP common-emitter amplifier stage providing 20–30 dB voltage gain with minimal noise contribution.

Use Value: 4.0 dB NF and h_FE ≥ 120 ensure signal integrity across -40°C to +125°C operating range.

Use Scenario: Driving LED indicators and small solenoids in door lock or mirror control circuits.

IC Role / Device Role / Timing Role: Saturated PNP switch controlling 100–150 mA loads from 5 V or 12 V rails.

Use Value: V_CE(SAT) ≤ -0.4 V reduces power loss and thermal rise in space-constrained modules.

Consumer Audio Preamp

Power Supply Enable Circuit

Use Scenario: First-stage gain block in portable headphone amplifiers or microphone preamps.

IC Role / Device Role / Timing Role: Low-noise, low-current PNP amplifier biased at ~100 µA for battery-efficient operation.

Use Value: 4.0 dB NF at 1 kHz and 100 µA bias enables clean audio capture without excessive quiescent draw.

Use Scenario: Enabling/disabling secondary LDOs or isolated power domains via microcontroller GPIO.

IC Role / Device Role / Timing Role: High-side switch controlled by active-low MCU output to assert enable signals.

Use Value: -25 V V_CEO and AEC-Q101 rating support reliable 5–12 V domain control in harsh environments.

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP small-signal transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MMBT3906-7-F	Same SOT23 package; h_FE min = 100 (vs. 120), V_CEO = -40 V (vs. -25 V), P_D = 310 mW (vs. 200 mW)	Higher voltage margin and power handling; slightly lower gain consistency at low currents	Preferred where higher V_CEO headroom or thermal margin is required; drop-in compatible with layout adjustment
PN2907A	TO-92 package; h_FE min = 100; V_CEO = -60 V; not AEC-Q101 qualified	Through-hole mounting only; lacks automotive qualification and green material compliance	Only for legacy through-hole designs or non-automotive prototypes; not recommended for new AEC-Q101 designs

Compared with MMBT4126-7-F, MMBT3906-7-F offers greater voltage and power headroom while maintaining identical footprint and RoHS/Green compliance, whereas PN2907A sacrifices qualification and packaging for cost-sensitive through-hole use.

Availability

MMBT4126-7-F is available at Aetrix Electronics and suitable for industrial sensor interface, automotive body control module, and consumer audio preamp applications requiring stable component supply despite its obsolete status.

Supply support for MMBT4126-7-F 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and North America.

The MMBT4126-7-F belongs to Diodes' general-purpose bipolar transistor product line, engineered for cost-effective, high-reliability switching and amplification in automotive, industrial, and consumer systems.

FAQ

Is MMBT4126-7-F still in production?

No - Diodes Incorporated has discontinued MMBT4126-7-F and marked it obsolete as of June 2021. It is no longer manufactured, but Aetrix Electronics maintains limited legacy stock and supports last-time buys with full traceability and documentation.

What is the functional replacement recommended by Diodes?

Diodes explicitly recommends MMBT3906-7-F as the direct functional replacement, citing identical SOT23 packaging, RoHS/Green compliance, AEC-Q101 qualification, and improved V_CEO (-40 V) and power rating (310 mW).

Can MMBT4126-7-F be used in new automotive designs?

While MMBT4126-7-F is AEC-Q101 qualified, its obsolete status makes it unsuitable for new automotive designs. Engineers should migrate to MMBT3906-7-F, which retains qualification and adds performance margin without layout changes.

What does the "-7-F" suffix indicate in the part number?

The "-7-F" denotes tape-and-reel packaging: "7" indicates a 7-inch reel, "F" signifies Diodes' standard green, halogen-free, RoHS-compliant finish; marking code "K2B" appears on the device top surface per SOT23 orientation.

MMBT4126-7-F Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: TO-236-3, SC-59, SOT-23-3

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 200 mA

Voltage - Collector Emitter Breakdown (Max):: 25 V

Vce Saturation (Max) @ Ib, Ic:: 400mV @ 5mA, 50mA

Current - Collector Cutoff (Max):: 50nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 120 @ 2mA, 1V

Power - Max:: 300 mW

Frequency - Transition:: 250MHz

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: Automotive

Qualification:: AEC-Q101

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

MMBT4126-7-F FAQ

1.How can I place an order for MMBT4126-7-F through Aetrix?

Please submit a Request for Quotation (RFQ) for MMBT4126-7-F 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 MMBT4126-7-F reliable?

The price and inventory of MMBT4126-7-F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBT4126-7-F is usually 5 days.

3.What payment methods are accepted for MMBT4126-7-F?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBT4126-7-F transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MMBT4126-7-F?

MMBT4126-7-F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MMBT4126-7-F 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 MMBT4126-7-F?

For technical support, including MMBT4126-7-F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBT4126-7-F requirements.

6.How does Aetrix verify that MMBT4126-7-F is sourced from the original manufacturer or authorized distributors?

All MMBT4126-7-F 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 MMBT4126-7-F meets industry standards.

7.What is the process for return or replacement of MMBT4126-7-F?

All MMBT4126-7-F units undergo pre-shipment inspection (PSI). If there is an issue with MMBT4126-7-F, 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 MMBT4126-7-F part is unused and in its original packaging.

Return procedure for MMBT4126-7-F:

1.Submit a request within 90 days.

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

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