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

onsemi MPS4124G

Name: MPS4124G
Brand: onsemi
SKU: MPS4124G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MPS4124G

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: MPS4124G.pdf

Description:: TRANS NPN 25V 0.2A TO92

Quantity:: RFQ Add To RFQ list

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Product details

Overview

MPS4124G from onsemi is an NPN silicon general-purpose amplifier transistor rated for 25 V_CE, 200 mA continuous collector current, and 625 mW power dissipation at T_A = 25°C, with DC current gain (h_FE) of 120–360 at I_C = 2.0 mA. It serves as a low-noise, medium-speed switching or linear amplification device in discrete analog front-ends and signal conditioning stages.

For engineers reviewing the MPS4124G datasheet, pinout, applications, or equivalent options, key selection criteria include its 170 MHz f_T, 5.0 dB noise figure at 1 kHz, TO-92 package compatibility, and verified V_CE(sat) ≤ 0.3 V at I_C = 50 mA / I_B = 5 mA - critical for low-loss biasing in audio preamps and sensor interface circuits.

Technical Context

The MPS4124G operates as a single NPN bipolar junction transistor optimized for small-signal amplification and medium-speed switching. Its design supports linear operation with h_fe = 120–480 at 1 kHz and f_T = 170 MHz, enabling stable gain up to VHF band edges in tuned amplifier stages.

Thermal performance is defined by R_JA = 200°C/W and R_JC = 83.3°C/W, permitting reliable operation from –55°C to +150°C junction temperature. Cutoff currents (I_CBO, I_EBO) are ≤ 50 nA, supporting high-impedance bias networks in precision analog circuits.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CE max	25 V - Supports rail-to-rail operation in 24 V logic-compatible or low-voltage analog systems
I_C continuous	200 mA - Enables drive capability for small relays, LED arrays, or pre-driver stages
h_FE range	120–360 at I_C = 2 mA - Ensures predictable DC bias stability across production lots
f_T	170 MHz - Allows use in RF amplifier stages up to ~30 MHz with adequate gain margin
NF	≤ 5.0 dB at 1 kHz - Meets low-noise requirements for microphone preamplifiers and sensor signal chains
V_CE(sat)	≤ 0.3 V at I_C = 50 mA / I_B = 5 mA - Minimizes conduction loss in saturated-switch applications
R_JA	200°C/W - Requires minimal heatsinking in ambient-ventilated PCB layouts

Pinout & Package

Package: TO-92 (CASE 29–11, TO-226AA), through-hole, 3-lead plastic package with standard lead configuration.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current sink terminal	Reference node for bias network; connects to ground or emitter resistor in common-emitter configurations
2 (Base)	Control input	Receives forward-biased current to modulate collector current; requires current-limiting resistor in most designs
3 (Collector)	Current source terminal	Delivers amplified output current; connects to load or next stage's input impedance

Key Features

Feature	Design Value
Low noise figure	≤ 5.0 dB at 1 kHz - Preserves SNR in microphone and piezoelectric sensor interfaces
High f_T	170 MHz - Enables broadband small-signal amplification without external compensation
Wide h_FE range	120–360 - Accommodates production spread while maintaining functional circuit margins
Low V_CE(sat)	≤ 0.3 V - Reduces power loss and thermal stress in switching-mode bias circuits
Robust thermal rating	T_J = –55°C to +150°C - Suitable for industrial control and automotive under-hood environments

Applications

Audio Preamp Stage	Sensor Signal Conditioning
Use Scenario: Amplifying low-level signals from electret microphones or dynamic pickups before ADC sampling. IC Role / Device Role / Timing Role: Discrete NPN transconductance amplifier in common-emitter topology with emitter degeneration. Use Value: 5.0 dB noise figure and h_fe ≥ 120 ensure >60 dB SNR at 1 kHz with minimal component count.	Use Scenario: Boosting weak outputs from thermistors, photodiodes, or strain gauges in measurement front-ends. IC Role / Device Role / Timing Role: Linear amplifier configured with precision feedback to achieve 10–100× gain with DC coupling. Use Value: Stable h_FE range and ≤50 nA I_CBO prevent drift-induced offset errors over temperature.
Low-Voltage Switch Driver	Discrete Logic Level Shifter
Use Scenario: Driving small solenoids, indicator LEDs, or optocoupler inputs from 3.3 V or 5 V MCU GPIOs. IC Role / Device Role / Timing Role: Saturated switch operating with I_B/I_C = 1/10 to ensure hard saturation and fast turn-off. Use Value: V_CE(sat) ≤ 0.3 V limits power dissipation to <15 mW at 50 mA, avoiding thermal derating.	Use Scenario: Translating 3.3 V logic outputs to 5 V or 12 V domains in mixed-supply embedded systems. IC Role / Device Role / Timing Role: Inverting level translator using common-emitter configuration with pull-up resistors. Use Value: f_T = 170 MHz supports clean edge transitions up to 10 Mbps without added propagation delay.

Audio Preamp Stage

Sensor Signal Conditioning

Use Scenario: Amplifying low-level signals from electret microphones or dynamic pickups before ADC sampling.

IC Role / Device Role / Timing Role: Discrete NPN transconductance amplifier in common-emitter topology with emitter degeneration.

Use Value: 5.0 dB noise figure and h_fe ≥ 120 ensure >60 dB SNR at 1 kHz with minimal component count.

Use Scenario: Boosting weak outputs from thermistors, photodiodes, or strain gauges in measurement front-ends.

IC Role / Device Role / Timing Role: Linear amplifier configured with precision feedback to achieve 10–100× gain with DC coupling.

Use Value: Stable h_FE range and ≤50 nA I_CBO prevent drift-induced offset errors over temperature.

Low-Voltage Switch Driver

Discrete Logic Level Shifter

Use Scenario: Driving small solenoids, indicator LEDs, or optocoupler inputs from 3.3 V or 5 V MCU GPIOs.

IC Role / Device Role / Timing Role: Saturated switch operating with I_B/I_C = 1/10 to ensure hard saturation and fast turn-off.

Use Value: V_CE(sat) ≤ 0.3 V limits power dissipation to <15 mW at 50 mA, avoiding thermal derating.

Use Scenario: Translating 3.3 V logic outputs to 5 V or 12 V domains in mixed-supply embedded systems.

IC Role / Device Role / Timing Role: Inverting level translator using common-emitter configuration with pull-up resistors.

Use Value: f_T = 170 MHz supports clean edge transitions up to 10 Mbps without added propagation delay.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN small-signal amplifier applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
BC547B	Lower f_T (300 MHz typical but not guaranteed min), h_FE = 200–450, same TO-92 package	Higher gain variation; less consistent noise performance (NF not specified)	Acceptable where bandwidth >100 MHz is not required and gain tolerance is relaxed
PN2222A	Higher V_CE (40 V), lower f_T (250 MHz typ), h_FE = 100–300, same TO-92 footprint	Better voltage headroom but reduced high-frequency linearity and higher V_CE(sat) (0.6 V)	Preferred for 30–40 V supply rails; avoid where low saturation loss or 170 MHz f_T is mandatory

Compared with BC547B and PN2222A, the MPS4124G delivers tighter f_T minimum (170 MHz), guaranteed NF ≤ 5.0 dB, and lower V_CE(sat), making it optimal for noise-sensitive, medium-bandwidth analog amplification where consistency matters.

Availability

MPS4124G is available at Aetrix Electronics and suitable for audio preamplifier design, sensor signal conditioning, low-voltage switching, and discrete logic level translation requiring stable component supply and full traceability.

Supply support for MPS4124G 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, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The MPS4124G belongs to onsemi's legacy small-signal transistor product line, engineered for reliability and consistency in discrete analog signal paths and general-purpose amplification tasks.

FAQ

What is the maximum collector-emitter voltage rating for the MPS4124G?

The MPS4124G has a maximum collector-emitter voltage (V_(BR)CEO) rating of 25 Vdc, tested at I_C = 1.0 mA with base open. This rating defines the absolute upper limit for voltage applied between collector and emitter in active or cutoff operation. Exceeding 25 V risks avalanche breakdown and permanent device damage. The MPS4124G must be used within this limit in all circuit configurations, including switching transients and inductive kickback scenarios.

Does the MPS4124G have a specified noise figure, and under what conditions is it measured?

Yes, the MPS4124G specifies a maximum noise figure (NF) of 5.0 dB, measured at I_C = 100 µA (not mA), V_CE = 5.0 V, R_S = 1.0 kΩ, and f = 1.0 kHz. This value reflects its suitability for low-noise small-signal amplification. The MPS4124G's NF performance is validated per onsemi's published test conditions and remains stable across its qualified operating temperature range.

What is the guaranteed minimum current gain (h_FE) for the MPS4124G at 2 mA collector current?

The MPS4124G guarantees a minimum DC current gain (h_FE) of 120 when tested at I_C = 2.0 mA and V_CE = 1.0 V, with typical values reaching 360. This minimum ensures predictable bias point stability in production circuits. Designers should reference this 120–360 range-not typical-only data-when calculating base resistor values or verifying worst-case gain margin for the MPS4124G.

Is the MPS4124G available in surface-mount packaging, or only through-hole?

The MPS4124G is exclusively offered in the TO-92 (CASE 29–11, TO-226AA) through-hole package, as confirmed by onsemi's official datasheet (Publication Order Number: MPS4124/D). No SMT variant (e.g., SOT-23 or SC-70) is listed or manufactured for the MPS4124G. For surface-mount alternatives, engineers should evaluate functionally similar parts such as the MMBT4401 or PZT4401, but those are distinct orderable parts-not pin-compatible versions of the MPS4124G.

What is the thermal resistance from junction to ambient (R_JA) for the MPS4124G in free-air conditions?

The MPS4124G has a specified thermal resistance from junction to ambient (R_JA) of 200°C/W under standard free-air test conditions (JEDEC JESD51-2). This value assumes no PCB copper pour or heatsinking. When mounted on a typical FR-4 board with 1-inch² 2-oz copper, R_JA improves significantly. The MPS4124G's R_JA directly determines allowable power dissipation at elevated ambient temperatures per its derating curve.

MPS4124G Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

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

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: NPN

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

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

Vce Saturation (Max) @ Ib, Ic:: 300mV @ 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)

MPS4124G FAQ

1.How can I place an order for MPS4124G through Aetrix?

Please submit a Request for Quotation (RFQ) for MPS4124G 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 MPS4124G reliable?

The price and inventory of MPS4124G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MPS4124G is usually 5 days.

3.What payment methods are accepted for MPS4124G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MPS4124G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MPS4124G?

MPS4124G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MPS4124G 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 MPS4124G?

For technical support, including MPS4124G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MPS4124G requirements.

6.How does Aetrix verify that MPS4124G is sourced from the original manufacturer or authorized distributors?

All MPS4124G 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 MPS4124G meets industry standards.

7.What is the process for return or replacement of MPS4124G?

All MPS4124G units undergo pre-shipment inspection (PSI). If there is an issue with MPS4124G, 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 MPS4124G part is unused and in its original packaging.

Return procedure for MPS4124G:

1.Submit a request within 90 days.

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

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