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

STMicroelectronics MJD350T4

Name: MJD350T4
Brand: STMicroelectronics
SKU: MJD350T4
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MJD350T4

Manufacturer:: STMicroelectronics

Category:: Single Bipolar Transistors

Package:: TO-252-3, DPAK (2 Leads + Tab), SC-63

Datasheet:: MJD350T4.pdf

Description:: TRANS PNP 300V 0.5A DPAK

Quantity:: RFQ Add To RFQ list

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Inventory:19,937

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Product details

Overview

MJD350T4 from STMicroelectronics is a complementary PNP silicon power transistor in TO-252 (DPAK) surface-mount package, rated for 300 V V_CEO, 0.5 A I_C, and 15 W P_tot at T_case ≤ 25 °C. It forms a matched pair with MJD340 for medium-voltage switching and amplification in solenoid/relay drivers and industrial control circuits.

For engineers reviewing the MJD350T4 datasheet, MJD350T4 pinout, MJD350T4 application, or MJD350T4 equivalent, key selection criteria include V_CEO(sus) = 300 V, h_FE = 30–240 at I_C = 50 mA, V_CE(sat) ≤ 1.5 V, rugged SOA performance, and DPAK thermal resistance R_thj-case = 8.33 °C/W.

Technical Context

The MJD350T4 is a medium-voltage PNP bipolar junction transistor fabricated using ST's Medium Voltage Epitaxial-Planar process, enabling high breakdown robustness and stable DC current gain across temperature. Its negative-polarity ratings (e.g., –300 V V_CEO, –0.5 A I_C) support complementary push-pull configurations with the NPN MJD340.

Designed for DC and pulsed switching up to 300 µs pulse width (≤2% duty cycle), it features a guaranteed V_CEO(sus) of 300 V at I_C = 1 mA and supports safe operation within defined SOA boundaries up to 150 °C junction temperature.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	–300 V: Maximum collector-emitter voltage before breakdown under open-base condition; enables use in 240 V AC line-switching and relay coil drive.
I_C	–0.5 A continuous: Rated collector current defines maximum steady-state load switching capability at T_case ≤ 25 °C.
P_tot	15 W at T_case ≤ 25 °C: Total dissipation limit; requires heatsinking above ~1 W ambient dissipation due to R_thj-amb = 100 °C/W.
h_FE	30–240 at I_C = –50 mA, V_CE = –10 V: DC current gain range determines base drive requirements for saturation in switching applications.
V_CE(sat)	≤ –1.5 V at I_C = –0.5 A, I_B = –0.05 A: Low saturation voltage minimizes conduction loss and self-heating during on-state operation.
R_thj-case	8.33 °C/W: Junction-to-case thermal resistance enables direct mounting to PCB copper or external heatsink for thermal management.

Pinout & Package

Package: TO-252 (DPAK), surface-mount, tape-and-reel (suffix "T4"), 3-terminal configuration with exposed drain pad (pin 2) for thermal and electrical connection.

Pin/Terminal	Circuit Role	Design Meaning
1	Emitter (E)	Current exit terminal; connected to higher potential rail in PNP high-side switch configurations.
2	Collector (C)	Main current sink terminal; electrically and thermally tied to exposed metal pad for low-inductance, high-power dissipation path.
3	Base (B)	Control input; requires negative bias relative to emitter to turn on; typical I_B = –50 mA for full saturation at I_C = –0.5 A.

Key Features

Feature	Design Value
Complementary pairing	Matched electrical specs with MJD340 (NPN) enable balanced push-pull output stages without gain or timing mismatch.
Medium-voltage ruggedness	300 V V_CEO(sus) rating supports reliable operation in 240 V AC solenoid and industrial relay driver circuits.
DPAK thermal performance	R_thj-case = 8.33 °C/W allows >10 W dissipation with minimal heatsink, reducing board space vs. through-hole alternatives.
Pulsed SOA compliance	Validated safe operating area up to 300 µs pulses ensures reliability in inductive load switching with flyback energy.

Applications

Solenoid Driver

Relay Interface Circuit

Use Scenario: Driving 24–240 V AC/DC solenoids in HVAC actuators and fluid control valves.

IC Role / Device Role / Timing Role: PNP high-side switch controlling current flow from supply rail to solenoid coil.

Use Value: 300 V V_CEO withstands inductive kickback; low V_CE(sat) reduces power loss and thermal stress during hold state.

Use Scenario: Isolating and amplifying microcontroller GPIO signals to energize electromechanical relays.

IC Role / Device Role / Timing Role: Medium-power interface transistor providing current gain and voltage level translation.

Use Value: h_FE ≥ 30 ensures sufficient drive with <10 mA MCU output; DPAK footprint simplifies automated assembly.

DC Motor Brake Control

Industrial PLC Output Stage

Use Scenario: Shorting motor terminals during dynamic braking in 24–48 V DC motor systems.

IC Role / Device Role / Timing Role: PNP switch sinking current from motor windings to ground via external diode path.

Use Value: 0.75 A I_CM peak rating handles brief brake-current surges; rugged SOA prevents secondary breakdown.

Use Scenario: Final output stage in programmable logic controller modules driving field loads (valves, indicators, small contactors).

IC Role / Device Role / Timing Role: High-reliability discrete switch replacing optocoupler + MOSFET combos in cost-sensitive designs.

Use Value: 150 °C T_j(max) and –65 °C to 150 °C T_stg support extended industrial temperature operation.

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP medium-voltage switching applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJE350	Through-hole TO-126 package; identical V_CEO, I_C, h_FE, but R_thj-amb = 80 °C/W (vs. 100 °C/W for MJD350T4).	Requires mechanical mounting and lead-forming; less suitable for high-density SMT production.	Select when legacy through-hole assembly or manual prototyping is required.
BDX54C	TO-126 package; V_CEO = –100 V (lower); h_FE = 20–120 (narrower range); P_tot = 15 W same.	Limited to ≤100 V applications; unsuitable for 240 V AC solenoid or relay drivers.	Select only for lower-voltage, cost-constrained industrial controls where 300 V margin is unnecessary.

Compared with MJE350 and BDX54C, the MJD350T4 offers surface-mount compatibility, superior thermal coupling via DPAK pad, and full 300 V capability-making it optimal for modern automated manufacturing of medium-voltage industrial interface circuits.

Availability

MJD350T4 is available at Aetrix Electronics and suitable for solenoid drivers, relay interface circuits, and industrial PLC output stages requiring stable component supply and long-term manufacturability.

Supply support for MJD350T4 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, digital, and mixed-signal ICs and discrete devices for automotive, industrial, and power applications.

The MJD340/MJD350 series belongs to ST's high-voltage bipolar transistor product line, engineered specifically for rugged, cost-effective medium-voltage switching in industrial actuation and control systems.

FAQ

Is MJD350T4 pin-compatible with MJD340?

No - MJD350T4 (PNP) and MJD340 (NPN) are complementary devices with identical TO-252 pinout (Emitter-Collector-Base), but opposite polarity. They share the same physical layout and thermal design, enabling symmetrical PCB placement in push-pull circuits without adapter routing.

What is the maximum allowable case temperature for continuous operation?

The absolute maximum case temperature is not explicitly specified, but continuous operation at full 15 W dissipation requires T_case ≤ 25 °C per datasheet derating. At higher case temperatures, power must be linearly reduced using R_thj-case = 8.33 °C/W - e.g., at T_case = 75 °C, max P_tot ≈ 9 W to maintain T_j ≤ 150 °C.

Can MJD350T4 replace MJE350 in existing designs?

Yes, with PCB layout adaptation: both share identical electrical specs (V_CEO, I_C, h_FE, SOA), but MJD350T4 uses surface-mount TO-252 versus MJE350's through-hole TO-126. Thermal performance differs - DPAK offers better R_thj-case, while TO-126 has lower R_thj-amb without heatsink.

Does MJD350T4 require a base resistor in switching applications?

Yes - a current-limiting base resistor is mandatory to set I_B ≥ I_C/h_FE(min) for saturation. For I_C = –0.5 A and h_FE(min) = 30, minimum I_B = –16.7 mA. With V_BE ≈ –1.2 V and 3.3 V/5 V logic drive, R_B should be 120–220 Ω to ensure hard saturation and minimize V_CE(sat).

MJD350T4 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-252-3, DPAK (2 Leads + Tab), SC-63

Packaging:: Tape & Reel (TR)

Product Status:: Active

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 500 mA

Voltage - Collector Emitter Breakdown (Max):: 300 V

Vce Saturation (Max) @ Ib, Ic:: -

Current - Collector Cutoff (Max):: 100µA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 30 @ 50mA, 10V

Power - Max:: 15 W

Frequency - Transition:: -

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: DPAK

MJD350T4 FAQ

1.How can I place an order for MJD350T4 through Aetrix?

Please submit a Request for Quotation (RFQ) for MJD350T4 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 MJD350T4 reliable?

The price and inventory of MJD350T4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MJD350T4 is usually 5 days.

3.What payment methods are accepted for MJD350T4?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MJD350T4 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MJD350T4?

MJD350T4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MJD350T4 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 MJD350T4?

For technical support, including MJD350T4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MJD350T4 requirements.

6.How does Aetrix verify that MJD350T4 is sourced from the original manufacturer or authorized distributors?

All MJD350T4 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 MJD350T4 meets industry standards.

7.What is the process for return or replacement of MJD350T4?

All MJD350T4 units undergo pre-shipment inspection (PSI). If there is an issue with MJD350T4, 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 MJD350T4 part is unused and in its original packaging.

Return procedure for MJD350T4:

1.Submit a request within 90 days.

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

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