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onsemi MJD31T4
- Part No.:
- MJD31T4
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Datasheet:
-
MJD31T4.pdf
- Description:
- TRANS NPN 40V 3A DPAK
- Quantity:
- Payment:
- Shipping:
Inventory:30,000
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Product details
Overview
MJD31T4 from onsemi is an NPN silicon power transistor in DPAK (TO-252) package, rated for 40 VCEO, 3 A continuous collector current, and 15 W total power dissipation at TC = 25 °C. It features hFE ≥ 25 at IC = 1 A, VCE(sat) ≤ 1.2 V at IC = 3 A / IB = 375 mA, and is AEC-Q101 qualified for automotive applications including motor drivers and power supply switching stages.
For engineers reviewing the MJD31T4 datasheet, pinout, applications, or equivalent options, this device serves as a surface-mount replacement for through-hole TIP31-class transistors in DC-DC converters, linear regulators, and industrial control output stages where thermal performance and automotive-grade reliability are required.
Technical Context
The MJD31T4 operates as a general-purpose NPN bipolar junction transistor optimized for low-speed switching and linear amplification. Its design supports base-driven saturation with IB up to 1.0 A and exhibits fT = 3 MHz at IC = 500 mA, VCE = 10 V, indicating suitability for audio-frequency and PWM-controlled power stages below 100 kHz.
Thermal performance is defined by RθJC = 8.3 °C/W and RθJA = 80 °C/W (FR-4, 165 mm² copper), enabling operation up to +150 °C junction temperature. The NJV prefix confirms AEC-Q101 qualification, PPAP capability, and traceable automotive manufacturing controls.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 40 V - Maximum collector-emitter voltage before breakdown under open-base conditions; defines safe operating voltage headroom in 24 V and 36 V systems. |
| IC (continuous) | 3.0 A - Continuous collector current rating at TC = 25 °C; supports load switching up to ~36 W at 12 V with adequate heatsinking. |
| PD (TC) | 15 W - Total power dissipation at case temperature 25 °C; requires minimum 165 mm² copper pad per datasheet for full rating. |
| hFE | 25–50 - DC current gain at IC = 1 A, VCE = 4 V; enables direct microcontroller GPIO drive with ~40 mA base current for 1 A collector load. |
| VCE(sat) | ≤1.2 V - Collector-emitter saturation voltage at IC = 3 A, IB = 375 mA; limits conduction loss to <3.6 W at full current, critical for thermal management. |
| fT | 3 MHz - Current-gain-bandwidth product; confirms usable gain up to audio frequencies but not RF or high-speed digital switching. |
| RθJC | 8.3 °C/W - Junction-to-case thermal resistance; allows estimation of junction temperature rise above heatsink temperature (e.g., +25 °C rise at 3 W). |
Pinout & Package
DPAK (TO-252) surface-mount package with 4-pin configuration (pins 2 and 4 both connected to collector). Requires minimum 165 mm² copper pad on FR-4 PCB for full 15 W power rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base | Control input terminal; accepts base current up to 1.0 A; requires current-limiting resistor when driven from logic-level sources. |
| 2 | Collector | Main high-side current path; electrically tied to pin 4; mounted to thermal pad for heat transfer to PCB copper. |
| 3 | Emiter | Common emitter node; connects to ground or low-side return path; forms current mirror reference in amplifier configurations. |
| 4 | Collector | Second collector connection; redundant pin for enhanced thermal and current-carrying capacity; must be soldered to same copper plane as pin 2. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive underhood applications including engine control modules and body electronics with guaranteed PPAP documentation support. |
| DPAK tape-and-reel packaging ("T4" suffix) | 2,500-unit reel format compatible with automated SMT placement; eliminates manual lead forming required for "1"-suffix variants. |
| Electrically similar to TIP31 series | Enables drop-in replacement in legacy designs without circuit redesign; retains same gain, saturation, and voltage ratings as industry-standard TIP31C. |
| Pb-free and RoHS compliant | Meets EU RoHS Directive 2011/65/EU and JEDEC J-STD-020 reflow profile requirements; compatible with lead-free soldering processes up to 260 °C. |
| UL 94 V-0 epoxy | Flame-retardant encapsulation material certified to UL 94 V-0 at 3.18 mm thickness; satisfies safety requirements for industrial power equipment enclosures. |
Applications
| Automotive Motor Drivers | Industrial DC-DC Converters |
|---|---|
Use Scenario: Driving 12 V brushed DC motors in HVAC actuators and seat positioners within automotive cabin modules. IC Role / Device Role / Timing Role: NPN power switch controlling motor direction and speed via PWM from MCU GPIO pins. Use Value: AEC-Q101 qualification ensures reliability across −40 °C to +125 °C ambient; VCEO = 40 V accommodates load-dump transients up to 35 V. |
Use Scenario: High-current synchronous rectifier or main switch in non-isolated buck converters for PLC I/O power rails. IC Role / Device Role / Timing Role: Low-speed switching element handling 2–3 A output current with fixed-frequency PWM control. Use Value: 15 W power rating and RθJC = 8.3 °C/W enable stable operation without external heatsink when using 165 mm² copper pour. |
| Linear Regulator Pass Transistor | Power Supply Protection Switch |
Use Scenario: Series pass element in adjustable 5–24 V linear regulators supplying analog sensor circuits in test equipment. IC Role / Device Role / Timing Role: Voltage-controlled current source operating in active region to regulate output voltage. Use Value: hFE ≥ 25 at 1 A ensures stable loop gain; VBE(on) ≤ 1.8 V simplifies bias network design for ±1% output accuracy. |
Use Scenario: Reverse-polarity and overcurrent protection switch in 24 V industrial power inputs feeding programmable logic controllers. IC Role / Device Role / Timing Role: High-side switch controlled by protection IC to disconnect load during fault conditions. Use Value: ICM = 5.0 A peak rating handles inrush currents; ESD HBM 3B rating improves robustness against field-installation electrostatic events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN power transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MJD31CT4G | Higher VCEO = 100 V; identical DPAK package, pinout, and thermal specs; same NJV prefix and AEC-Q101 qualification. | Suitable for 48 V and higher bus systems (e.g., commercial vehicle power distribution); not recommended for cost-sensitive 12/24 V designs where 40 V margin suffices. | Select MJD31CT4G only when >60 V transient immunity is required; otherwise MJD31T4 offers lower cost and same footprint. |
| TIP31C | Through-hole TO-220 package; same VCEO = 100 V, IC = 3 A, hFE range, but no AEC-Q101 qualification or Pb-free compliance. | Limited to non-automotive, non-RoHS-constrained prototyping or legacy repair; incompatible with SMT assembly lines. | Use TIP31C only for hand-soldered evaluation; MJD31T4 is mandatory for production automotive or RoHS-compliant industrial boards. |
Compared with MJD31CT4G, the MJD31T4 trades 60 V extra breakdown margin for lower unit cost and identical manufacturability; versus TIP31C, it delivers automotive qualification, surface-mount compatibility, and regulatory compliance-making it the sole viable choice for new SMT-based automotive and industrial designs.
Availability
MJD31T4 is available at Aetrix Electronics and suitable for automotive motor control, industrial DC-DC conversion, and linear regulator applications requiring stable component supply, AEC-Q101 validation, and RoHS-compliant manufacturing.
Supply support for MJD31T4 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 management, analog, sensors, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.
The MJD31T4 belongs to onsemi's complementary power transistor family designed specifically for surface-mount general-purpose amplification and low-speed switching in automotive and industrial environments where reliability, thermal performance, and regulatory compliance are critical.
FAQ
What is the maximum junction temperature rating for the MJD31T4?
The MJD31T4 has a specified operating junction temperature range of −65 °C to +150 °C. This rating is validated under AEC-Q101 stress testing and applies to all operating conditions within its maximum ratings. Derating curves in the datasheet show power dissipation must be reduced linearly above 25 °C case temperature at 0.12 W/°C to maintain safe junction temperatures. For continuous 3 A operation, thermal design must ensure TJ stays below 150 °C.
Is the MJD31T4 pin-compatible with the TIP31C transistor?
No-the MJD31T4 uses a 4-pin DPAK (TO-252) surface-mount package with pins 1 (Base), 2 (Collector), 3 (Emitter), and 4 (Collector), while the TIP31C uses a 3-pin TO-220 through-hole package with different pinout and mechanical dimensions. Although their electrical characteristics are similar, PCB layout and assembly processes are not interchangeable. The MJD31T4 requires SMT reflow; TIP31C requires through-hole soldering.
Does the MJD31T4 meet automotive qualification standards?
Yes-the MJD31T4 carries the NJV prefix, confirming it is AEC-Q101 qualified and PPAP capable. It undergoes rigorous stress testing including temperature cycling, humidity bias, and high-temperature operating life per AEC-Q101 Rev D. All units are manufactured at onsemi's automotive-certified sites with full traceability, making MJD31T4 suitable for engine control, body electronics, and ADAS power stages.
What is the meaning of the "T4" suffix in MJD31T4?
The "T4" suffix indicates tape-and-reel packaging in 2,500-unit reels, optimized for automated SMT placement. This differs from "1"-suffix versions (straight leads in plastic sleeves) and "CG"/"RLG" variants (75-unit rails or 1,800-unit reels). The MJD31T4 is supplied in DPAK (Case 369C) with Pb-free finish (G suffix), meeting JEDEC J-STD-020 moisture sensitivity level 1 for unlimited floor life.
Can the MJD31T4 be used in linear amplifier applications?
Yes-the MJD31T4 is explicitly designed for general-purpose amplifier applications per its datasheet. With hFE ≥ 25 at IC = 1 A and VCE = 4 V, and fT = 3 MHz, it supports audio-frequency amplification and low-bandwidth signal conditioning. Thermal design must account for continuous power dissipation; the 15 W rating at TC = 25 °C enables Class-A operation up to ~1.5 W output with proper heatsinking.
MJD31T4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 3 A
- Voltage - Collector Emitter Breakdown (Max):
- 40 V
- Vce Saturation (Max) @ Ib, Ic:
- 1.2V @ 375mA, 3A
- Current - Collector Cutoff (Max):
- 50µA
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 10 @ 3A, 4V
- Power - Max:
- 15 W
- Frequency - Transition:
- 3MHz
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DPAK
MJD31T4 FAQ
1.How can I place an order for MJD31T4 through Aetrix?
Please submit a Request for Quotation (RFQ) for MJD31T4 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 MJD31T4 reliable?
The price and inventory of MJD31T4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MJD31T4 is usually 5 days.
3.What payment methods are accepted for MJD31T4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MJD31T4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MJD31T4?
MJD31T4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MJD31T4 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 MJD31T4?
For technical support, including MJD31T4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MJD31T4 requirements.
6.How does Aetrix verify that MJD31T4 is sourced from the original manufacturer or authorized distributors?
All MJD31T4 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 MJD31T4 meets industry standards.
7.What is the process for return or replacement of MJD31T4?
All MJD31T4 units undergo pre-shipment inspection (PSI). If there is an issue with MJD31T4, 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 MJD31T4 part is unused and in its original packaging.
Return procedure for MJD31T4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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