Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

onsemi MPS4126RLRAG

Name: MPS4126RLRAG
Brand: onsemi
SKU: MPS4126RLRAG
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: MPS4126RLRAG

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: MPS4126RLRAG.pdf

Description:: TRANS PNP 25V 0.2A TO92

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:7,153

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

MPS4126RLRAG from onsemi is a PNP silicon amplifier transistor in TO-92 package, rated for −25 V V_CE, −200 mA I_C, and 625 mW P_D at T_A = 25°C, with h_FE = 120–360 at I_C = −2 mA and f_T = 170 MHz - used in low-power audio preamplifier stages and discrete switching circuits.

For engineers reviewing the MPS4126RLRAG datasheet, pinout, applications, or equivalent options, key selection criteria include verified PNP gain linearity at −50 mA, V_CE(sat) ≤ −0.4 V, thermal resistance R_JA = 200 °C/W, and Pb-free TO-92 mechanical compatibility with legacy 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) spans 120–360 across −2 mA to −50 mA collector currents, and small-signal current gain (h_fe) reaches up to 480 at 1 kHz, supporting wideband analog signal conditioning.

It exhibits f_T = 170 MHz under −10 mA I_C, V_CE = −20 V bias, with C_ob = 4.5 pF and C_ib = 11.5 pF - enabling stable operation in RF-coupled preamp and oscillator buffer designs up to ~50 MHz.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CE	−25 V - maximum safe voltage between collector and emitter in reverse-active or saturation mode
I_C	−200 mA - continuous DC collector current handling without thermal runaway at 25°C ambient
P_D @ T_A	625 mW - total power dissipation limit at 25°C ambient, derating 5 mW/°C above that temperature
h_FE	120–360 - DC current gain range at −2 mA I_C, defining base drive requirements for linear amplification
f_T	170 MHz - transition frequency confirming usable bandwidth for VHF preamplifier and oscillator applications
V_CE(sat)	≤ −0.4 V - low saturation voltage at −50 mA I_C/−5 mA I_B, minimizing conduction loss in switching use
R_JA	200 °C/W - junction-to-ambient thermal resistance, indicating need for heatsinking above ~300 mW dissipation

Pinout & Package

Package: TO-92 (Case 29-11), straight or bent lead variant, Pb-free, 2000 pcs per tape-and-reel reel.

Pin/Terminal	Circuit Role	Design Meaning
1	Emitter	Current exit terminal in PNP configuration; connects to most positive rail in common-base or common-collector topologies
2	Base	Control terminal; negative bias relative to emitter required to forward-bias base-emitter junction and enable conduction
3	Collector	Current entry terminal; typically tied to load or supply rail in switching, or to feedback network in amplifier configurations

Key Features

Feature	Design Value
Pb-free TO-92 packaging	Complies with RoHS Directive 2011/65/EU; compatible with standard SnPb and lead-free solder reflow profiles
High f_T bandwidth	170 MHz transition frequency enables stable small-signal amplification up to VHF band without external compensation
Low V_CE(sat)	≤ −0.4 V at −50 mA ensures <100 mW conduction loss in switching applications, reducing thermal stress
Wide h_FE range	120–360 supports consistent gain matching across production lots when binned, easing analog circuit calibration
Low noise figure	NF ≤ 4.0 dB at −100 µA I_C makes it suitable for low-level signal amplification in sensor front-ends

Applications

Audio Preamp Stage	Discrete Switch Driver
Use Scenario: Amplifying microphone or piezoelectric sensor output before ADC sampling in portable instrumentation. IC Role / Device Role / Timing Role: PNP common-emitter amplifier providing 20–30 dB voltage gain with minimal distortion. Use Value: h_FE ≥ 120 and NF ≤ 4.0 dB ensure high SNR and stable bias point across temperature.	Use Scenario: Driving relay coils or LED arrays from microcontroller GPIO pins with inverted logic control. IC Role / Device Role / Timing Role: Saturated PNP switch sinking current from load to ground via emitter-follower or common-emitter configuration. Use Value: V_CE(sat) ≤ −0.4 V limits power loss to <20 mW at 50 mA, avoiding thermal shutdown in compact enclosures.
RF Oscillator Buffer	Current Mirror Reference
Use Scenario: Isolating Colpitts or Clapp oscillator core from variable load impedance in VHF transmitter modules. IC Role / Device Role / Timing Role: Common-collector buffer stage preserving oscillation frequency stability while delivering drive current. Use Value: f_T = 170 MHz and C_ib = 11.5 pF minimize loading effect and phase shift up to 50 MHz.	Use Scenario: Building matched current sources in analog IC test fixtures or precision DAC output buffers. IC Role / Device Role / Timing Role: One leg of a discrete PNP current mirror with emitter degeneration resistors for thermal tracking. Use Value: Tight h_FE spread (120–360) and low I_CBO ≤ −50 nA support <1% current mismatch over −40°C to +125°C.

Audio Preamp Stage

Discrete Switch Driver

Use Scenario: Amplifying microphone or piezoelectric sensor output before ADC sampling in portable instrumentation.

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

Use Value: h_FE ≥ 120 and NF ≤ 4.0 dB ensure high SNR and stable bias point across temperature.

Use Scenario: Driving relay coils or LED arrays from microcontroller GPIO pins with inverted logic control.

IC Role / Device Role / Timing Role: Saturated PNP switch sinking current from load to ground via emitter-follower or common-emitter configuration.

Use Value: V_CE(sat) ≤ −0.4 V limits power loss to <20 mW at 50 mA, avoiding thermal shutdown in compact enclosures.

RF Oscillator Buffer

Current Mirror Reference

Use Scenario: Isolating Colpitts or Clapp oscillator core from variable load impedance in VHF transmitter modules.

IC Role / Device Role / Timing Role: Common-collector buffer stage preserving oscillation frequency stability while delivering drive current.

Use Value: f_T = 170 MHz and C_ib = 11.5 pF minimize loading effect and phase shift up to 50 MHz.

Use Scenario: Building matched current sources in analog IC test fixtures or precision DAC output buffers.

IC Role / Device Role / Timing Role: One leg of a discrete PNP current mirror with emitter degeneration resistors for thermal tracking.

Use Value: Tight h_FE spread (120–360) and low I_CBO ≤ −50 nA support <1% current mismatch over −40°C to +125°C.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BC557B	Lower f_T (100 MHz), higher V_CE(sat) (−0.65 V), same TO-92 package and pinout	Less suitable for >30 MHz small-signal amplification; acceptable for DC/low-frequency switching	Choose BC557B only if bandwidth demand is <5 MHz and cost sensitivity outweighs gain-bandwidth trade-off
PN2907A	Higher P_D (625 mW same), but lower h_FE min (100), wider V_CE rating (−60 V)	Better for high-voltage switching; less linear gain control in low-noise preamp roles	Select PN2907A when operating above −30 V supply or requiring ruggedized industrial switching over precision analog gain

Compared with BC557B and PN2907A, MPS4126RLRAG delivers superior f_T-to-V_CE(sat) ratio and tighter h_FE distribution - making it optimal for compact, wideband, low-noise discrete amplifier stages where thermal margin and gain consistency are critical.

Availability

MPS4126RLRAG is available at Aetrix Electronics and suitable for audio preamplifiers, discrete switching drivers, RF oscillator buffers, and current mirror references requiring stable component supply and full traceability.

Supply support for MPS4126RLRAG 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 focused on energy-efficient electronics, delivering power management, analog, sensors, and discrete solutions.

MPS4126RLRAG belongs to onsemi's general-purpose bipolar transistor product line, engineered for reliable performance in consumer, industrial, and communications equipment where cost-effective, Pb-free through-hole amplification is required.

FAQ

What is the maximum collector current rating for MPS4126RLRAG?

The MPS4126RLRAG is rated for −200 mA continuous collector current (I_C) at T_A = 25°C. Derating applies above this temperature - 5 mW/°C for ambient-limited dissipation. At higher ambient temperatures or with poor PCB heat spreading, practical I_C must be reduced to maintain junction temperature below 150°C. The MPS4126RLRAG datasheet specifies absolute maximum ratings, not recommended operating conditions.

Is MPS4126RLRAG pin-compatible with BC557 series transistors?

Yes, MPS4126RLRAG uses the standard TO-92 package with identical pinout: Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector - matching BC557, BC558, and PN2907 families. However, electrical characteristics differ: MPS4126RLRAG offers higher f_T (170 MHz vs. 100 MHz) and lower V_CE(sat) (−0.4 V vs. −0.65 V), so direct substitution may require bias adjustment in sensitive analog circuits.

Does MPS4126RLRAG meet RoHS requirements?

Yes, MPS4126RLRAG is a Pb-free device compliant with EU RoHS Directive 2011/65/EU. The "G" suffix in the part number explicitly denotes Pb-free packaging. It supports both SnPb and lead-free soldering processes, with thermal profiles validated per J-STD-020 for moisture sensitivity level (MSL) 1 - unlimited floor life at ≤30°C/60% RH.

What is the typical noise figure of MPS4126RLRAG and at what conditions is it measured?

The MPS4126RLRAG has a maximum noise figure (NF) of 4.0 dB, measured at I_C = −100 µA, V_CE = −5.0 V, R_S = 1.0 kΩ, and f = 1.0 kHz. This low-noise performance makes the MPS4126RLRAG suitable for amplifying weak signals from microphones, thermopiles, or photodiodes where preserving signal integrity is critical.

Can MPS4126RLRAG be used in switching power supply feedback circuits?

Yes, MPS4126RLRAG can serve in optocoupler-based feedback paths or discrete error amplifier stages within offline AC/DC or DC/DC converters. Its −25 V V_CE, low V_CE(sat), and stable h_FE support reliable operation in isolated voltage regulation loops. However, for high-frequency (>100 kHz) PWM control, dedicated high-speed transistors or integrated error amps are preferred over the MPS4126RLRAG due to its 170 MHz f_T limitation.

MPS4126RLRAG 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)

MPS4126RLRAG FAQ

1.How can I place an order for MPS4126RLRAG through Aetrix?

Please submit a Request for Quotation (RFQ) for MPS4126RLRAG 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 MPS4126RLRAG reliable?

The price and inventory of MPS4126RLRAG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MPS4126RLRAG is usually 5 days.

3.What payment methods are accepted for MPS4126RLRAG?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MPS4126RLRAG transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MPS4126RLRAG?

MPS4126RLRAG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MPS4126RLRAG 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 MPS4126RLRAG?

For technical support, including MPS4126RLRAG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MPS4126RLRAG requirements.

6.How does Aetrix verify that MPS4126RLRAG is sourced from the original manufacturer or authorized distributors?

All MPS4126RLRAG 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 MPS4126RLRAG meets industry standards.

7.What is the process for return or replacement of MPS4126RLRAG?

All MPS4126RLRAG units undergo pre-shipment inspection (PSI). If there is an issue with MPS4126RLRAG, 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 MPS4126RLRAG part is unused and in its original packaging.

Return procedure for MPS4126RLRAG:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-09 Counterfeit Electronic Components: How to Detect, Authenticate, and Test Suspect Parts

Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…