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onsemi MJD128T4G
- Part No.:
- MJD128T4G
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Datasheet:
-
MJD128T4G.pdf
- Description:
- TRANS PNP DARL 120V 8A DPAK
- Quantity:
- Payment:
- Shipping:
Inventory:5,219
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Product details
Overview
MJD128T4G from onsemi is a PNP complementary Darlington power transistor in DPAK (TO-252) package, rated for 120 VCEO, 8 A continuous collector current, and 20 W power dissipation at TC = 25°C. It delivers high DC current gain (hFE = 2500 typ. @ IC = 4 A), low saturation voltage (VCE(sat) ≤ 2 V @ IC/IB = 250), and is designed for general-purpose amplification and low-speed switching in industrial power control circuits.
For engineers reviewing the MJD128T4G datasheet, pinout, applications, or equivalent options, this device is selected for robustness in relay drivers, linear regulators, and motor control stages where high current gain, thermal stability up to +150°C junction temperature, and AEC-Q101 qualification for automotive-grade reliability are critical design requirements.
Technical Context
The MJD128T4G implements a monolithic Darlington pair with integrated base-emitter shunt resistors to ensure stable turn-off and reduce external component count. Its structure supports high-current gain without external bias networks, enabling direct drive from microcontroller GPIOs or logic-level sources.
Thermal performance is defined by RJC = 6.25°C/W (junction-to-case) and RJA = 71.4°C/W (junction-to-ambient on minimum recommended pad), making it suitable for surface-mount applications with heatsinked DPAK mounting. The device operates across −65°C to +150°C junction temperature range and meets UL 94 V-0 flammability rating.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 120 V - Maximum collector-emitter voltage before breakdown; enables use in 100 V bus systems with safety margin. |
| IC (cont.) | 8 A - Continuous collector current capability; supports medium-power loads like solenoids and fan motors. |
| PD @ TC=25°C | 20 W - Power dissipation limit with case heatsinking; defines maximum steady-state output power under thermal management. |
| hFE (typ.) | 2500 @ IC=4 A - High DC current gain reduces required base drive current, easing interface with low-current controllers. |
| VCE(sat) | ≤2 V @ IC/IB=250 - Low saturation voltage minimizes conduction loss and heat generation in switching applications. |
| TJ Range | −65°C to +150°C - Wide operating junction temperature range supports deployment in harsh environments including automotive under-hood. |
| ESD HBM | >8000 V - Robust electrostatic discharge immunity simplifies handling and board-level ESD protection design. |
Pinout & Package
DPAK (TO-252-3) surface-mount package with exposed drain pad (pin 4) electrically connected to collector; thermally optimized for PCB copper area attachment. Dimensions: 6.10 × 6.54 × 2.28 mm, pitch 2.29 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Base) | Control input node | Receives base current to enable Darlington conduction; internal shunt resistor ensures reliable turn-off without external pull-down. |
| 2 (Collector) | Main current sink path | Primary high-current output terminal; pins 2 and 4 are internally tied to collector, doubling current-carrying capacity and improving thermal path. |
| 3 (Emitter) | Current return path | Common emitter connection for PNP operation; referenced to system ground or positive rail depending on circuit topology. |
| 4 (Collector) | Secondary collector terminal | Electrically identical to pin 2; used for enhanced thermal conduction and mechanical stability in high-power layouts. |
Key Features
| Feature | Design Value |
|---|---|
| Monolithic Darlington with built-in base-emitter shunt resistors | Eliminates need for external turn-off resistors, reducing BOM count and layout complexity in driver stages. |
| AEC-Q101 qualified and PPAP capable | Validated for automotive applications including body control modules and lighting drivers requiring zero-defect reliability. |
| UL 94 V-0 epoxy package | Meets stringent flammability standards for industrial equipment enclosures and safety-critical power supplies. |
| High hFE (2500 typ. @ 4 A) | Enables direct drive from 3.3 V/5 V logic outputs with minimal base current (<1.6 mA typical), lowering MCU GPIO loading. |
| Low VCE(sat) (≤2 V @ IC/IB=250) | Reduces conduction losses to <1.6 W at 8 A, improving efficiency and easing thermal design in compact form factors. |
Applications
| Relay Driver Stage | Linear Regulator Pass Element |
|---|---|
|
Use Scenario: Driving 12 V/24 V electromagnetic relays in PLC I/O modules and HVAC control panels. IC Role / Device Role / Timing Role: PNP Darlington switch providing high-current sinking capability to energize relay coils with minimal control-side components. Use Value: High hFE allows single-transistor drive from 5 V microcontrollers; low VCE(sat) prevents coil voltage droop during activation. |
Use Scenario: As pass transistor in adjustable linear regulators delivering up to 5 A for FPGA or analog subsystem power rails. IC Role / Device Role / Timing Role: Series-pass element regulating output voltage via feedback-controlled base current; handles full load current and dissipates excess power. Use Value: 20 W TC-rated dissipation supports 5 A × 4 V dropout = 20 W worst-case loss without derating at moderate heatsink temperatures. |
| DC Motor Speed Control | Automotive Lamp Dimming |
|
Use Scenario: Low-frequency PWM-driven H-bridge half-bridge stage controlling brushed DC fans or window lift motors in industrial machinery. IC Role / Device Role / Timing Role: High-side PNP switch in unidirectional motor drive configuration; handles stall currents up to 8 A continuously. Use Value: 120 VCEO rating accommodates back-EMF spikes from 24 V motors; thermal robustness ensures reliability during extended stall conditions. |
Use Scenario: Constant-current dimming of incandescent or halogen lamps in automotive interior lighting and dashboard backlighting. IC Role / Device Role / Timing Role: Linear current regulator configured as emitter-follower to set lamp current independent of supply variation. Use Value: AEC-Q101 qualification and −65°C to +150°C operation guarantee compliance with automotive ambient and transient requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP Darlington power transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MJD112T4G | Lower VCEO (100 V), same DPAK package and hFE profile; lower PD (15 W). | Suitable for ≤80 V systems only; not recommended for 100–120 V bus designs where MJD128T4G's 120 V rating provides margin. | Select when cost sensitivity outweighs voltage headroom needs and thermal budget permits reduced power dissipation. |
| BDX54C | TO-126 through-hole package; VCEO = 100 V, IC = 8 A, hFE = 750 min; no AEC-Q101 qualification. | Lacks surface-mount compatibility and automotive qualification; requires manual assembly and additional ESD handling controls. | Choose only for legacy through-hole designs or prototyping where DPAK reflow is unavailable and automotive compliance is not required. |
Compared with MJD128T4G, MJD112T4G offers cost savings in lower-voltage applications but sacrifices bus voltage margin, while BDX54C trades modern packaging and qualification for legacy compatibility-neither matches the combination of 120 V rating, AEC-Q101, and DPAK thermal performance offered by MJD128T4G.
Availability
MJD128T4G is available at Aetrix Electronics and suitable for industrial motor control, automotive lighting drivers, and programmable power supply designs requiring stable component supply, long-term lifecycle support, and traceable Pb-free sourcing.
Supply support for MJD128T4G 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, sensor, and connectivity solutions for automotive, industrial, cloud, and IoT markets.
The MJD128T4G belongs to onsemi's complementary Darlington power transistor family, engineered for high-current, medium-voltage switching and amplification in space-constrained surface-mount applications demanding reliability and thermal resilience.
FAQ
What is the maximum continuous collector current rating for MJD128T4G?
The MJD128T4G is rated for 8 A continuous collector current (IC) at case temperature TC = 25°C. Derating applies above 25°C at 0.16 W/°C, and actual usable current depends on PCB copper area, heatsinking, and ambient conditions. At TC = 100°C, the effective IC drops to approximately 5.2 A based on thermal limits.
Is MJD128T4G pin-compatible with other DPAK PNP transistors like MJD112T4G?
Yes, MJD128T4G shares the same DPAK-3 (TO-252-3) package outline and pinout (Base–Collector–Emitter–Collector) with MJD112T4G, enabling direct PCB footprint reuse. However, differences in VCEO (120 V vs. 100 V) and power dissipation (20 W vs. 15 W) require verification of voltage margin and thermal design in the target application before substitution.
Does MJD128T4G include built-in protection features?
The MJD128T4G integrates base-emitter shunt resistors to ensure reliable turn-off without external components, but it does not include intrinsic overtemperature shutdown, short-circuit protection, or current limiting. External protection-such as base current limiting, snubbers, and heatsink temperature monitoring-must be implemented per application requirements.
What is the significance of the "NJV" prefix in NJVMJD128T4G?
The "NJV" prefix in NJVMJD128T4G indicates an automotive-grade variant meeting AEC-Q101 stress test requirements and PPAP process capability. It denotes unique site and control change tracking for automotive customers, with identical electrical specifications and DPAK packaging as the standard MJD128T4G, but with enhanced traceability and qualification documentation.
Can MJD128T4G be used in linear regulator configurations?
Yes, MJD128T4G is commonly deployed as a pass transistor in adjustable linear regulators due to its high hFE, low VCE(sat), and 20 W power dissipation capability at TC = 25°C. Designers must ensure adequate heatsinking and verify safe operating area (SOA) curves-especially second breakdown limits-under worst-case dropout and load conditions.
MJD128T4G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Transistor Type:
- PNP - Darlington
- Current - Collector (Ic) (Max):
- 8 A
- Voltage - Collector Emitter Breakdown (Max):
- 120 V
- Vce Saturation (Max) @ Ib, Ic:
- 4V @ 80mA, 8A
- Current - Collector Cutoff (Max):
- 5mA
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 1000 @ 4A, 4V
- Power - Max:
- 1.75 W
- Frequency - Transition:
- 4MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DPAK
MJD128T4G FAQ
1.How can I place an order for MJD128T4G through Aetrix?
Please submit a Request for Quotation (RFQ) for MJD128T4G 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 MJD128T4G reliable?
The price and inventory of MJD128T4G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MJD128T4G is usually 5 days.
3.What payment methods are accepted for MJD128T4G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MJD128T4G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MJD128T4G?
MJD128T4G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MJD128T4G 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 MJD128T4G?
For technical support, including MJD128T4G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MJD128T4G requirements.
6.How does Aetrix verify that MJD128T4G is sourced from the original manufacturer or authorized distributors?
All MJD128T4G 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 MJD128T4G meets industry standards.
7.What is the process for return or replacement of MJD128T4G?
All MJD128T4G units undergo pre-shipment inspection (PSI). If there is an issue with MJD128T4G, 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 MJD128T4G part is unused and in its original packaging.
Return procedure for MJD128T4G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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