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

onsemi MPS4126RLRA

Name: MPS4126RLRA
Brand: onsemi
SKU: MPS4126RLRA
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MPS4126RLRA

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-226-3, TO-92-3 Long Body, Formed Leads

Datasheet:: MPS4126RLRA.pdf

Description:: TRANS PNP 25V 0.2A TO92

Quantity:: RFQ Add To RFQ list

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Product details

Overview

MPS4126RLRA from onsemi is a PNP silicon general-purpose amplifier transistor rated for –25 V V_CE, –200 mA I_C, and 625 mW power dissipation at T_A = 25°C, with h_FE = 120–360 at I_C = –2 mA and f_T = 170 MHz - used in low-noise audio preamplifier stages and signal switching circuits.

For engineers reviewing the MPS4126RLRA datasheet, pinout, applications, or equivalent options, key selection criteria include verified V_(BR)CEO = –25 V, guaranteed h_FE min of 120 at low current, saturation voltage ≤ –0.4 V at I_C = –50 mA/I_B = –5 mA, noise figure ≤ 4.0 dB, and TO-92 package compatibility with through-hole PCB layouts.

Technical Context

This discrete PNP bipolar junction transistor operates in linear amplification and saturated switching modes. Its DC current gain (h_FE) varies from 120 to 360 depending on collector current, and it delivers f_T = 170 MHz under specified small-signal conditions, supporting RF-coupled audio and medium-speed digital switching.

Thermal performance is defined by R_JA = 200°C/W and R_JC = 83.3°C/W, enabling operation from –55°C to +150°C junction temperature. Cutoff currents are tightly controlled: I_CBO ≤ –50 nA and I_EBO ≤ –50 nA, ensuring stable biasing in high-impedance emitter-follower configurations.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CE max	–25 Vdc - supports rail-to-rail operation in negative-supply analog stages up to ±25 V systems
I_C continuous	–200 mAdc - sufficient for driver-stage amplification and relay/LED load switching
h_FE range	120–360 - enables predictable DC bias design across production lots at I_C = –2 mA
f_T	170 MHz - suitable for VHF preamp and narrowband RF coupling up to ~100 MHz
V_CE(sat)	≤ –0.4 Vdc at I_C = –50 mA/I_B = –5 mA - ensures low conduction loss in saturated switch applications
NF	≤ 4.0 dB at I_C = –100 µA - meets low-noise requirement for microphone and sensor front-end amplifiers
R_JA	200°C/W - defines thermal derating slope (5.0 mW/°C above 25°C ambient) for board-level thermal design

Pinout & Package

Package: TO-92 (CASE 29–04, STYLE 1), through-hole, epoxy-molded plastic with 3 leads. Standard lead form per ON Semiconductor issue AD.

Pin/Terminal	Circuit Role	Design Meaning
1	Emitter	Current exit terminal; connects to most negative node in PNP bias network
2	Base	Control input; requires current-limited drive to achieve target I_C and avoid saturation overshoot
3	Collector	Current entry terminal; ties to supply rail or load return path in common-emitter configuration

Key Features

Feature	Design Value
High h_FE consistency	Min 120 at I_C = –2 mA reduces base drive current requirements in battery-powered designs
Low V_CE(sat)	≤ –0.4 V at rated I_C/I_B minimizes power loss and self-heating in switching mode
Controlled leakage	I_CBO, I_EBO ≤ –50 nA ensure stable quiescent point over temperature and time
Wide T_J range	–55°C to +150°C operation supports industrial and automotive under-hood environments

Applications

Audio Preamp Stage	DC Load Switch
Use Scenario: Low-voltage, single-supply microphone amplifier with passive bias network. IC Role / Device Role / Timing Role: PNP amplifier transistor configured as common-emitter voltage amplifier with fixed emitter resistor. Use Value: 4.0 dB noise figure and h_FE ≥ 120 enable clean signal gain before ADC sampling without added op-amp complexity.	Use Scenario: Microcontroller-driven LED or relay control in 5 V/12 V industrial I/O modules. IC Role / Device Role / Timing Role: Saturated PNP switch turning on grounded loads via microcontroller GPIO pull-down. Use Value: V_CE(sat) ≤ –0.4 V ensures <100 mW dissipation at 100 mA load, eliminating need for heatsinking.
RF Signal Coupler	Current Mirror Reference
Use Scenario: Interstage coupling in 30–80 MHz IF amplifier chain for AM receiver front-end. IC Role / Device Role / Timing Role: Small-signal amplifier with tuned collector load and emitter degeneration. Use Value: f_T = 170 MHz and C_ob ≤ 4.5 pF support stable gain up to third harmonic without peaking or instability.	Use Scenario: Precision current source in analog sensor conditioning circuit with matched transistor pair. IC Role / Device Role / Timing Role: Emitter-follower configured as active current sink with stable h_FE-based scaling. Use Value: Tight h_FE spread (120–360) and low I_CBO allow <±2% current matching across temperature in dual-MPS4126 implementations.

Audio Preamp Stage

DC Load Switch

Use Scenario: Low-voltage, single-supply microphone amplifier with passive bias network.

IC Role / Device Role / Timing Role: PNP amplifier transistor configured as common-emitter voltage amplifier with fixed emitter resistor.

Use Value: 4.0 dB noise figure and h_FE ≥ 120 enable clean signal gain before ADC sampling without added op-amp complexity.

Use Scenario: Microcontroller-driven LED or relay control in 5 V/12 V industrial I/O modules.

IC Role / Device Role / Timing Role: Saturated PNP switch turning on grounded loads via microcontroller GPIO pull-down.

Use Value: V_CE(sat) ≤ –0.4 V ensures <100 mW dissipation at 100 mA load, eliminating need for heatsinking.

RF Signal Coupler

Current Mirror Reference

Use Scenario: Interstage coupling in 30–80 MHz IF amplifier chain for AM receiver front-end.

IC Role / Device Role / Timing Role: Small-signal amplifier with tuned collector load and emitter degeneration.

Use Value: f_T = 170 MHz and C_ob ≤ 4.5 pF support stable gain up to third harmonic without peaking or instability.

Use Scenario: Precision current source in analog sensor conditioning circuit with matched transistor pair.

IC Role / Device Role / Timing Role: Emitter-follower configured as active current sink with stable h_FE-based scaling.

Use Value: Tight h_FE spread (120–360) and low I_CBO allow <±2% current matching across temperature in dual-MPS4126 implementations.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BC557B	V_CE = –45 V, I_C = –100 mA, h_FE = 200–450, f_T ≈ 100 MHz, TO-92	Higher voltage rating but lower current capability; slightly lower bandwidth	Preferred where higher breakdown margin is needed and load current stays below 100 mA
PN2907A	V_CE = –60 V, I_C = –600 mA, h_FE = 100–300, f_T ≈ 150 MHz, TO-92	Higher current and voltage ratings, but larger V_CE(sat) (≤ –1.6 V) and higher thermal resistance	Chosen when driving heavier loads (>200 mA) and thermal budget allows higher R_JA

Compared with BC557B and PN2907A, the MPS4126RLRA offers optimal balance of bandwidth (170 MHz), low-noise performance (≤4.0 dB), and moderate power handling (625 mW), making it especially suited for compact, high-fidelity audio and RF-coupled signal paths where both gain linearity and frequency response matter.

Availability

MPS4126RLRA is available at Aetrix Electronics and suitable for audio preamplifier stages, DC load switching, RF signal coupling, and current mirror reference circuits requiring stable component supply and consistent h_FE distribution.

Supply support for MPS4126RLRA 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 delivering energy-efficient, high-performance silicon solutions for automotive, industrial, cloud, medical, and IoT applications.

The MPS4126RLRA belongs to onsemi's general-purpose bipolar transistor product line, designed for cost-sensitive, high-reliability linear amplification and switching in consumer, industrial, and communications equipment.

FAQ

What is the maximum collector-emitter voltage rating for the MPS4126RLRA?

The MPS4126RLRA has a maximum collector-emitter voltage rating of –25 Vdc, specified as V(BR)_CEO with I_C = –1.0 mA and I_B = 0. This rating is confirmed in the OFF CHARACTERISTICS table of the official onsemi datasheet (Publication Order Number: MPS4126/D, Rev. 2). Exceeding this voltage risks avalanche breakdown and permanent device damage. The MPS4126RLRA must be operated within this limit in all circuit configurations.

Does the MPS4126RLRA have a guaranteed minimum h_FE at operating current?

Yes, the MPS4126RLRA guarantees h_FE ≥ 120 at I_C = –2.0 mA and V_CE = –1.0 V, and h_FE ≥ 60 at I_C = –50 mA under the same V_CE. These values are published in the ON CHARACTERISTICS section of the onsemi datasheet. Designers can rely on this minimum h_FE for robust bias network calculations. The MPS4126RLRA's h_FE range remains valid across its full operating temperature range.

What is the thermal resistance from junction to ambient for the MPS4126RLRA in free-air conditions?

The thermal resistance from junction to ambient (R_JA) for the MPS4126RLRA is 200°C/W, measured under standard test conditions (JEDEC JESD51-2) on FR-4 PCB with no copper pour. This value governs the device's power derating: above 25°C ambient, allowable power dissipation decreases by 5.0 mW/°C. The MPS4126RLRA's R_JA is directly tied to its TO-92 package construction and mounting method.

Is the MPS4126RLRA suitable for low-noise audio applications?

Yes, the MPS4126RLRA is characterized for noise figure ≤ 4.0 dB at I_C = –100 µA, V_CE = –5.0 V, R_S = 1.0 kΩ, and f = 1.0 kHz - meeting typical requirements for microphone preamplifiers and sensor signal conditioning. Its low I_CBO (≤ –50 nA) and stable h_FE further support low-distortion, high-SNR operation. The MPS4126RLRA's noise performance is validated in the SMALL–SIGNAL CHARACTERISTICS section of the datasheet.

What are the pin assignments for the MPS4126RLRA in its TO-92 package?

Viewing the MPS4126RLRA with the flat side facing forward and leads pointing downward, Pin 1 is Emitter, Pin 2 is Base, and Pin 3 is Collector - per CASE 29–04, STYLE 1 mechanical drawing in the onsemi datasheet. This pinout is standardized across all MPS4126 variants including MPS4126RLRA. Incorrect orientation during PCB layout or assembly will result in circuit malfunction or device failure.

MPS4126RLRA Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 Long Body, Formed Leads

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:: 625 mW

Frequency - Transition:: 170MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92 (TO-226)

MPS4126RLRA FAQ

1.How can I place an order for MPS4126RLRA through Aetrix?

Please submit a Request for Quotation (RFQ) for MPS4126RLRA 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 MPS4126RLRA reliable?

The price and inventory of MPS4126RLRA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MPS4126RLRA is usually 5 days.

3.What payment methods are accepted for MPS4126RLRA?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MPS4126RLRA transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MPS4126RLRA?

MPS4126RLRA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MPS4126RLRA 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 MPS4126RLRA?

For technical support, including MPS4126RLRA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MPS4126RLRA requirements.

6.How does Aetrix verify that MPS4126RLRA is sourced from the original manufacturer or authorized distributors?

All MPS4126RLRA 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 MPS4126RLRA meets industry standards.

7.What is the process for return or replacement of MPS4126RLRA?

All MPS4126RLRA units undergo pre-shipment inspection (PSI). If there is an issue with MPS4126RLRA, 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 MPS4126RLRA part is unused and in its original packaging.

Return procedure for MPS4126RLRA:

1.Submit a request within 90 days.

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

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