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

onsemi MPS4124

Name: MPS4124
Brand: onsemi
SKU: MPS4124
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MPS4124

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: MPS4124.pdf

Description:: TRANS NPN 25V 0.2A TO92

Quantity:: RFQ Add To RFQ list

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Inventory:6,367

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Product details

Overview

MPS4124 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 and f_T = 170 MHz - used in low-noise audio preamplifier stages and signal switching circuits.

For engineers reviewing the MPS4124 datasheet, pinout, applications, or equivalent options, key selection considerations include its TO-92 package, V_CE(sat) ≤ 0.3 V at I_C = 50 mA/I_B = 5 mA, noise figure ≤ 5.0 dB, and thermal resistance R_JA = 200 °C/W - critical for compact linear amplifier designs requiring stable gain and low thermal rise.

Technical Context

The MPS4124 operates as a medium-speed, low-noise NPN bipolar junction transistor optimized for small-signal amplification and switching. Its h_FE range (120–360) supports bias stability across production lots, while f_T = 170 MHz enables RF front-end use up to VHF band.

It features low C_ob = 4.0 pF and C_ib = 13.5 pF, supporting high-input-impedance configurations. V_BE(sat) ≤ 0.95 V and V_CE(sat) ≤ 0.3 V ensure efficient operation in Class-A amplifier stages and digital logic interface drivers.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CE max	25 V - sets maximum supply rail for common-emitter amplifier stages without breakdown
I_C continuous	200 mA - supports moderate-power driver and preamp output stages
P_D @ T_A = 25°C	625 mW - defines thermal headroom in ambient-mounted PCB applications
h_FE @ I_C = 2 mA	120–360 - ensures predictable DC bias point across temperature and unit variation
f_T	170 MHz - enables stable small-signal amplification up to ~30 MHz with gain margin
NF @ 1 kHz	≤ 5.0 dB - meets low-noise requirements in microphone preamps and sensor interfaces

Pinout & Package

Package: TO-92 (Case 29–11, TO-226AA), through-hole, 3-lead plastic package with standard lead configuration and 2.54 mm lead pitch.

Pin/Terminal	Circuit Role	Design Meaning
1	Emitter	Reference node for bias network; connects to ground or emitter degeneration resistor
2	Base	Control input; requires current-limited drive due to low V_BE(sat) and h_FE-dependent I_B
3	Collector	Output node; carries full load current and dissipates majority of device power

Key Features

Feature	Design Value
Low noise figure	≤ 5.0 dB at 1 kHz - preserves SNR in analog front-ends before ADC or active filtering
High f_T	170 MHz - supports wideband amplification without external compensation
Stable h_FE range	120–360 at I_C = 2 mA - simplifies bias design and reduces production calibration need
Low saturation voltages	V_CE(sat) ≤ 0.3 V, V_BE(sat) ≤ 0.95 V - minimizes voltage drop and power loss in switching mode

Applications

Audio Preamp Stage	Sensor Signal Amplifier
Use Scenario: Boosting weak signals from electret microphones or piezoelectric transducers before ADC sampling. IC Role / Device Role / Timing Role: Small-signal NPN amplifier in common-emitter configuration with emitter degeneration. Use Value: NF ≤ 5.0 dB and h_FE ≥ 120 maintain signal integrity and gain consistency across units and temperature.	Use Scenario: Amplifying low-level outputs from thermistors, photodiodes, or strain gauges in industrial monitoring systems. IC Role / Device Role / Timing Role: DC-coupled transimpedance or voltage amplifier with stable bias point. Use Value: V_CE = 25 V and I_C = 200 mA support rail-to-rail swing and drive capability into 10 kΩ loads.
Switching Interface Driver	RF Detector Stage
Use Scenario: Level-shifting and current boosting between MCU GPIOs and relay coils or LED arrays. IC Role / Device Role / Timing Role: Saturated switch with base-driven control and fast turn-on/turn-off. Use Value: V_CE(sat) ≤ 0.3 V and h_FE ≥ 60 at I_C = 50 mA minimize conduction loss and simplify base resistor selection.	Use Scenario: Demodulating AM signals or detecting RF envelope in VHF receiver front-ends. IC Role / Device Role / Timing Role: Nonlinear detector using base-emitter junction, leveraging f_T = 170 MHz bandwidth. Use Value: C_ob = 4.0 pF and f_T = 170 MHz enable reliable detection up to 30 MHz with minimal capacitance loading.

Audio Preamp Stage

Sensor Signal Amplifier

Use Scenario: Boosting weak signals from electret microphones or piezoelectric transducers before ADC sampling.

IC Role / Device Role / Timing Role: Small-signal NPN amplifier in common-emitter configuration with emitter degeneration.

Use Value: NF ≤ 5.0 dB and h_FE ≥ 120 maintain signal integrity and gain consistency across units and temperature.

Use Scenario: Amplifying low-level outputs from thermistors, photodiodes, or strain gauges in industrial monitoring systems.

IC Role / Device Role / Timing Role: DC-coupled transimpedance or voltage amplifier with stable bias point.

Use Value: V_CE = 25 V and I_C = 200 mA support rail-to-rail swing and drive capability into 10 kΩ loads.

Switching Interface Driver

RF Detector Stage

Use Scenario: Level-shifting and current boosting between MCU GPIOs and relay coils or LED arrays.

IC Role / Device Role / Timing Role: Saturated switch with base-driven control and fast turn-on/turn-off.

Use Value: V_CE(sat) ≤ 0.3 V and h_FE ≥ 60 at I_C = 50 mA minimize conduction loss and simplify base resistor selection.

Use Scenario: Demodulating AM signals or detecting RF envelope in VHF receiver front-ends.

IC Role / Device Role / Timing Role: Nonlinear detector using base-emitter junction, leveraging f_T = 170 MHz bandwidth.

Use Value: C_ob = 4.0 pF and f_T = 170 MHz enable reliable detection up to 30 MHz with minimal capacitance loading.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
2N3904	Lower f_T (300 MHz typical but not guaranteed min), lower h_FE min (100), higher V_CE(sat) (0.4 V)	Less suitable for VHF detection; acceptable for general-purpose switching where gain tolerance is relaxed	Choose when cost sensitivity outweighs guaranteed f_T and noise performance
BC547B	Higher h_FE min (200), lower V_CE max (45 V), no specified NF or f_T in datasheet	Preferred for DC-coupled linear amps needing tighter h_FE spread; unsuitable for verified RF detection	Choose when bias stability is priority and RF bandwidth is not required

Compared with 2N3904 and BC547B, the MPS4124 provides guaranteed minimum f_T (170 MHz), documented noise figure (≤5.0 dB), and tighter V_CE(sat) spec - making it preferred for audio preamps and VHF detector stages where parameter assurance matters.

Availability

MPS4124 is available at Aetrix Electronics and suitable for audio preamplifier stages, sensor signal conditioning, switching interface drivers, and RF detector circuits requiring stable component supply and consistent small-signal gain.

Supply support for MPS4124 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 innovation for automotive, industrial, cloud, and IoT applications.

The MPS4124 belongs to onsemi's general-purpose bipolar transistor product line, designed for reliable, low-cost amplification and switching in consumer, industrial, and communications equipment.

FAQ

What is the maximum collector-emitter voltage rating for the MPS4124?

The MPS4124 has a maximum collector-emitter voltage (V_CE) rating of 25 Vdc, tested under I_C = 1.0 mA and I_B = 0 conditions. This rating defines the absolute upper limit for voltage applied between collector and emitter in active or saturated operation - exceeding it risks avalanche breakdown and permanent device damage. Designers must maintain derating margins in high-temperature environments per the datasheet's thermal curves.

Does the MPS4124 have a guaranteed minimum current gain (h_FE)?

Yes, the MPS4124 specifies a minimum h_FE of 120 at I_C = 2.0 mA and V_CE = 1.0 V, and 60 at I_C = 50 mA and V_CE = 1.0 V. These guaranteed minima allow robust bias network design without lot-to-lot recalibration. The maximum h_FE is 360 at low current, supporting flexibility in gain-setting resistor selection for the MPS4124.

What is the thermal resistance from junction to ambient (R_JA) for the MPS4124?

The MPS4124 has a thermal resistance from junction to ambient (R_JA) of 200 °C/W when mounted on a standard FR-4 PCB with no heatsink. This value assumes natural convection and defines the temperature rise above ambient per watt of dissipated power. For reliable operation at full 625 mW, ambient temperature must remain below +125°C - underscoring the need for layout-aware thermal design around the MPS4124.

Can the MPS4124 be used in RF applications?

Yes, the MPS4124 is qualified for RF applications up to ~30 MHz due to its guaranteed f_T of 170 MHz and low capacitances (C_ob = 4.0 pF, C_ib = 13.5 pF). It is commonly used in VHF detector stages and low-gain RF amplifier sections. However, it is not characterized for impedance matching or S-parameters - system-level validation is required for each MPS4124 implementation in RF signal paths.

What is the package type and pin configuration of the MPS4124?

The MPS4124 uses a TO-92 (Case 29–11, TO-226AA) through-hole plastic package with three leads. Pin 1 is Emitter, Pin 2 is Base, and Pin 3 is Collector - verified by onsemi's official package drawing and marking orientation. This standardized pinout ensures compatibility with legacy PCB footprints designed for similar NPN transistors like the 2N3904, though electrical parameters differ.

MPS4124 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)

MPS4124 FAQ

1.How can I place an order for MPS4124 through Aetrix?

Please submit a Request for Quotation (RFQ) for MPS4124 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 MPS4124 reliable?

The price and inventory of MPS4124 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MPS4124 is usually 5 days.

3.What payment methods are accepted for MPS4124?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MPS4124 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MPS4124?

MPS4124 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MPS4124 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 MPS4124?

For technical support, including MPS4124 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MPS4124 requirements.

6.How does Aetrix verify that MPS4124 is sourced from the original manufacturer or authorized distributors?

All MPS4124 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 MPS4124 meets industry standards.

7.What is the process for return or replacement of MPS4124?

All MPS4124 units undergo pre-shipment inspection (PSI). If there is an issue with MPS4124, 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 MPS4124 part is unused and in its original packaging.

Return procedure for MPS4124:

1.Submit a request within 90 days.

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

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