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

onsemi MPSA44RL1G

Name: MPSA44RL1G
Brand: onsemi
SKU: MPSA44RL1G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MPSA44RL1G

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: MPSA44RL1G.pdf

Description:: TRANS NPN 400V 0.3A TO92

Quantity:: RFQ Add To RFQ list

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Product details

Overview

MPSA44RL1G from onsemi is an NPN silicon high-voltage general-purpose transistor in TO-92 package, rated for 400 V_CEO, 300 mA continuous collector current, and 625 mW power dissipation at 25°C ambient. It delivers DC current gain (h_FE) of 40–200 across 1–100 mA I_C, with V_CE(sat) ≤ 0.75 V at I_C = 50 mA/I_B = 5 mA, and is used in high-voltage switching circuits such as relay drivers and flyback snubbers.

For engineers reviewing the MPSA44RL1G datasheet, pinout, applications, or equivalent options, key selection criteria include its 400 V breakdown rating, TO-92 leaded package compatibility with through-hole prototyping and industrial control PCBs, thermal resistance (R_JA = 200°C/W), and verified performance in 150 V switching waveforms with <500 ns turn-off time.

Technical Context

This NPN bipolar junction transistor operates in active, saturation, and cutoff regions with defined safe operating area (SOA) limits up to 300 mA and 400 V. Its high V_CBO (500 V) and low leakage (I_CBO ≤ 0.1 A, I_CES ≤ 500 nA) support reliable blocking in off-state high-voltage nodes.

Small-signal parameters include C_ibo = 130 pF and C_obo = 7.0 pF at specified bias conditions, and |h_fe| ≥ 1.0 at 20 MHz, confirming suitability for moderate-frequency switching-not RF amplification-where capacitive loading and gain stability matter.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	400 V - Supports switching loads up to 400 V DC without breakdown under typical base drive.
I_C (continuous)	300 mA - Enables driving medium-current loads like small relays or indicator LEDs in series with high-side resistors.
P_D @ T_A = 25°C	625 mW - Limits usable power in ambient-air convection cooling; derates 5 mW/°C above 25°C.
h_FE @ I_C = 10 mA	50–200 - Ensures predictable base current sizing (e.g., ~200 µA for 10 mA collector load) across production lots.
V_CE(sat) @ I_C/I_B = 10	0.5 V max - Minimizes conduction loss and self-heating when fully saturated in switching applications.
T_J range	−55°C to +150°C - Qualified for use in industrial temperature environments including motor control enclosures.

Pinout & Package

Package: TO-92 (Case 29-11, Style 1), through-hole, Pb-free, with standard lead configuration and 2.54 mm pin pitch.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current exit node in NPN operation	Connected to ground or low-side return path; base-emitter junction forward-biased during turn-on.
2 (Base)	Control input for minority-carrier injection	Receives current-limited drive (e.g., via 1–10 kΩ resistor); small-signal or switching logic-level compatible.
3 (Collector)	High-voltage current entry node	Connected to positive rail or inductive load; sustains 400 V reverse bias when off.

Key Features

Feature	Design Value
High V_CBO (500 V)	Enables robust voltage margin in flyback transformer primary-side switching and snubber networks.
Low I_CES (≤500 nA)	Reduces standby power loss in always-on high-voltage monitoring circuits.
TO-92 mechanical standardization	Ensures drop-in replacement capability across legacy designs using MPSA42/MPSA44 family footprints.
Specified SOA curve	Provides validated second-breakdown immunity up to 100 µs pulse width at 200 mA/200 V, critical for inductive load handling.

Applications

Relay Driver Circuits	High-Voltage Signal Switching
Use Scenario: Driving 12–24 VDC electromagnetic relays with coil inductance >100 mH in PLC I/O modules. IC Role / Device Role / Timing Role: NPN switch controlling relay coil current; handles back-EMF clamping via external diode. Use Value: 400 V_CEO rating prevents breakdown during 300–400 V transient spikes induced by relay de-energization.	Use Scenario: Routing analog or digital signals between isolated high-voltage domains in test equipment front-ends. IC Role / Device Role / Timing Role: High-voltage analog switch enabling signal path selection without optocoupler latency. Use Value: Low C_obo (7.0 pF) minimizes capacitive feedthrough, preserving signal integrity up to 10 MHz.
Flyback Converter Snubber	Industrial Sensor Interface
Use Scenario: Absorbing voltage spikes across transformer primary windings in offline AC/DC converters. IC Role / Device Role / Timing Role: Active clamp transistor dissipating energy during MOSFET turn-off transitions. Use Value: Verified SOA up to 200 V/100 mA for 100 µs pulses ensures reliability under repetitive surge conditions.	Use Scenario: Level-shifting and isolating 4–20 mA current loop outputs in hazardous-area transmitters. IC Role / Device Role / Timing Role: High-side current sink transistor interfacing with field-side 24 V supply rails. Use Value: −55°C to +150°C junction range supports operation in explosion-proof enclosures with wide ambient swings.

Relay Driver Circuits

High-Voltage Signal Switching

Use Scenario: Driving 12–24 VDC electromagnetic relays with coil inductance >100 mH in PLC I/O modules.

IC Role / Device Role / Timing Role: NPN switch controlling relay coil current; handles back-EMF clamping via external diode.

Use Value: 400 V_CEO rating prevents breakdown during 300–400 V transient spikes induced by relay de-energization.

Use Scenario: Routing analog or digital signals between isolated high-voltage domains in test equipment front-ends.

IC Role / Device Role / Timing Role: High-voltage analog switch enabling signal path selection without optocoupler latency.

Use Value: Low C_obo (7.0 pF) minimizes capacitive feedthrough, preserving signal integrity up to 10 MHz.

Flyback Converter Snubber

Industrial Sensor Interface

Use Scenario: Absorbing voltage spikes across transformer primary windings in offline AC/DC converters.

IC Role / Device Role / Timing Role: Active clamp transistor dissipating energy during MOSFET turn-off transitions.

Use Value: Verified SOA up to 200 V/100 mA for 100 µs pulses ensures reliability under repetitive surge conditions.

Use Scenario: Level-shifting and isolating 4–20 mA current loop outputs in hazardous-area transmitters.

IC Role / Device Role / Timing Role: High-side current sink transistor interfacing with field-side 24 V supply rails.

Use Value: −55°C to +150°C junction range supports operation in explosion-proof enclosures with wide ambient swings.

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage NPN switching applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MPSA42RL1G	Lower V_CEO (300 V vs. 400 V); identical TO-92 package and pinout.	Not suitable for 400 V bus applications; acceptable only where peak voltage remains ≤250 V.	Select MPSA42RL1G only if system maximum transient voltage is confirmed ≤250 V and cost optimization is prioritized.
BC639-16	Same V_CEO (400 V), but lower I_C (100 mA vs. 300 mA); TO-92, same pinout.	Limited to low-power switching; insufficient for >100 mA relay coils or snubber duty.	Choose BC639-16 only for signal-level switching where current demand stays below 80 mA.

Compared with MPSA44RL1G, MPSA42RL1G trades 100 V headroom for cost reduction, while BC639-16 sacrifices current capacity for tighter h_FE tolerance-neither offers full functional equivalence, and both require validation of voltage/current margins in the target circuit.

Availability

MPSA44RL1G is available at Aetrix Electronics and suitable for industrial control systems, high-voltage sensor interfaces, and relay-based automation requiring stable component supply and long-term manufacturability.

Supply support for MPSA44RL1G 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 specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The MPSA44RL1G belongs to onsemi's legacy high-voltage bipolar transistor product line, designed specifically for robust, cost-effective switching in industrial and power-supply applications where reliability under voltage stress is critical.

FAQ

What is the maximum collector-emitter voltage rating for MPSA44RL1G?

The MPSA44RL1G has a guaranteed minimum V_CEO rating of 400 Vdc at I_C = 1.0 mAdc and T_A = 25°C. This rating is validated per JEDEC test conditions and defines the absolute maximum DC voltage the device can block in open-base, common-emitter configuration without breakdown. Designers must maintain at least 20% margin below this value in production circuits.

Is MPSA44RL1G pin-compatible with other TO-92 NPN transistors like MPSA42RL1G?

Yes, MPSA44RL1G uses the standard TO-92 (Case 29-11) package with Emitter-Base-Collector pinout (pin 1 = emitter, pin 2 = base, pin 3 = collector), matching MPSA42RL1G and BC639-16. However, direct substitution requires verification of V_CEO, I_C, and SOA requirements-MPSA42RL1G is rated only to 300 V, making it unsuitable for 400 V applications despite identical pinout.

What is the typical DC current gain (h_FE) of MPSA44RL1G at 10 mA collector current?

At I_C = 10 mAdc and V_CE = 10 Vdc, the MPSA44RL1G exhibits h_FE ranging from 50 (minimum) to 200 (maximum) across production lots. The typical median value is approximately 100, supporting conservative base resistor design-for example, a 47 kΩ resistor from 5 V logic yields ~100 µA I_B, sufficient to saturate the MPSA44RL1G at 10 mA I_C.

Does MPSA44RL1G meet RoHS and Pb-free requirements?

Yes, MPSA44RL1G is a Pb-free (lead-free) device compliant with RoHS Directive 2011/65/EU. The "G" suffix explicitly denotes Pb-free packaging, and the device uses matte tin lead finish with no lead content exceeding 0.1 wt%. Full compliance documentation, including material declarations and test reports, is available from onsemi's quality portal.

Can MPSA44RL1G be used in linear amplifier applications?

No-the MPSA44RL1G is characterized and optimized for switching operation, not linear amplification. Its h_fe variation across I_C and temperature, lack of specified linearity parameters (e.g., distortion, THD), and SOA limitations make it unsuitable for audio or precision analog gain stages. For amplification, onsemi recommends devices like MMBT5551 or PZT2222A with verified small-signal linearity.

MPSA44RL1G 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:: NPN

Current - Collector (Ic) (Max):: 300 mA

Voltage - Collector Emitter Breakdown (Max):: 400 V

Vce Saturation (Max) @ Ib, Ic:: 750mV @ 5mA, 50mA

Current - Collector Cutoff (Max):: 500nA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 50 @ 10mA, 10V

Power - Max:: 625 mW

Frequency - Transition:: -

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

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

MPSA44RL1G FAQ

1.How can I place an order for MPSA44RL1G through Aetrix?

Please submit a Request for Quotation (RFQ) for MPSA44RL1G 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 MPSA44RL1G reliable?

The price and inventory of MPSA44RL1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MPSA44RL1G is usually 5 days.

3.What payment methods are accepted for MPSA44RL1G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MPSA44RL1G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MPSA44RL1G?

MPSA44RL1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MPSA44RL1G 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 MPSA44RL1G?

For technical support, including MPSA44RL1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MPSA44RL1G requirements.

6.How does Aetrix verify that MPSA44RL1G is sourced from the original manufacturer or authorized distributors?

All MPSA44RL1G 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 MPSA44RL1G meets industry standards.

7.What is the process for return or replacement of MPSA44RL1G?

All MPSA44RL1G units undergo pre-shipment inspection (PSI). If there is an issue with MPSA44RL1G, 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 MPSA44RL1G part is unused and in its original packaging.

Return procedure for MPSA44RL1G:

1.Submit a request within 90 days.

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

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