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onsemi MJE802STU
- Part No.:
- MJE802STU
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-225AA, TO-126-3
- Datasheet:
-
MJE802STU.pdf
- Description:
- TRANS NPN DARL 80V 4A TO-126-3
- Quantity:
- Payment:
- Shipping:
Inventory:4,194
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Product details
Overview
MJE802STU from ON Semiconductor (formerly Fairchild) is an NPN epitaxial silicon Darlington transistor in TO-126 package, rated for 80 V VCEO, 4 A IC, and 40 W PC at TC = 25°C, with built-in base-emitter resistors (R1 ≈ 10 kΩ, R2 ≈ 0.6 kΩ), used in high-gain linear and switching applications such as relay drivers and power supply control circuits.
For engineers reviewing the MJE802STU datasheet, pinout, applications, or equivalent options, key selection criteria include its 80 V collector-emitter breakdown voltage, 750 minimum hFE at IC = 1.5 A, monolithic Darlington construction with integrated biasing resistors, TO-126 thermal performance, and complementary pairing with MJE702.
Technical Context
The MJE802STU implements a monolithic Darlington pair with integrated base-emitter resistors (R1 ≈ 10 kΩ, R2 ≈ 0.6 kΩ), enabling simplified biasing and eliminating external resistor networks. Its architecture delivers high DC current gain (hFE ≥ 750 at IC = 1.5 A) while maintaining VCE(sat) ≤ 2.5 V under same conditions.
It operates within a junction temperature range of –55°C to +150°C and supports safe operating area (SOA) compliance up to 5 ms pulse width at 80 V/4 A. Thermal derating begins at TC = 25°C, reaching zero dissipation at TC = 175°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 80 V - Maximum allowable collector-emitter voltage before breakdown; enables use in 48 V and 60 V industrial power rails. |
| IC | 4 A - Continuous collector current rating; supports medium-power switching loads like solenoids and fan motors. |
| PC | 40 W @ TC = 25°C - Power dissipation capability with heatsink; requires thermal design for >25°C case temperatures. |
| hFE | ≥750 @ IC = 1.5 A - High DC current gain reduces required base drive current, easing microcontroller interface. |
| VCE(sat) | ≤2.5 V @ IC = 1.5 A, IB = 30 mA - Low saturation voltage minimizes conduction loss in linear and switching modes. |
| R1 / R2 | ≈10 kΩ / ≈0.6 kΩ - Integrated bias resistors enable self-biasing without external components, reducing BOM count. |
Pinout & Package
Package: TO-126 (3-lead, through-hole, thermally enhanced plastic). Dimensions: 16.10 × 13.06 × 4.2 mm (L × W × H), with mounting hole ø3.20 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Emitter connection of Darlington pair | Low-impedance output node; connects to ground or load return path; electrically tied to metal tab for thermal conduction. |
| 2 (Collector) | Collector connection of Darlington pair | Main power output node; connects to load high-side; electrically connected to metal tab for heat sinking. |
| 3 (Base) | Input control terminal | Drives internal Darlington pair via integrated R1/R2 network; accepts TTL/CMOS-compatible logic-level signals. |
Key Features
| Feature | Design Value |
|---|---|
| Monolithic Darlington with integrated bias resistors | Eliminates need for external base resistors, reducing PCB footprint and component count in relay and lamp driver designs. |
| High hFE ≥ 750 at IC = 1.5 A | Enables direct drive from low-current MCU GPIOs (e.g., 3.3 V/20 mA outputs) without additional buffer stages. |
| VCEO = 80 V rating | Supports operation across 24 V, 48 V, and 60 V industrial control buses with margin against transients. |
| TO-126 package with metal tab | Provides mechanical robustness and efficient thermal path to heatsink; compatible with standard through-hole assembly processes. |
Applications
| Relay Driver Circuit | DC Motor Speed Control |
|---|---|
Use Scenario: Driving 24 V/1 A electromagnetic relays in PLC I/O modules. IC Role / Device Role / Timing Role: High-gain switch amplifying microcontroller GPIO signals to energize relay coils. Use Value: Built-in R1/R2 resistors simplify drive circuitry; 80 V VCEO accommodates coil flyback spikes up to 70 V. | Use Scenario: PWM-controlled 48 V brushed DC motor in industrial automation actuators. IC Role / Device Role / Timing Role: Main switching element in low-frequency (<10 kHz) linear/PWM motor driver stage. Use Value: 4 A IC and 40 W PC support continuous 3 A motor current with heatsinking; low VCE(sat) reduces conduction loss. |
| Linear Regulator Pass Element | Power Supply Enable Switch |
Use Scenario: Series pass transistor in adjustable 5–30 V, 2 A linear power supplies. IC Role / Device Role / Timing Role: Voltage-controlled current source regulating output voltage via feedback loop. Use Value: High hFE ensures stable regulation with minimal base drive error; SOA supports safe operation under overload. | Use Scenario: High-side enable switch controlling 12 V/3 A subsystem power in automotive body control modules. IC Role / Device Role / Timing Role: Load switch isolating downstream circuitry during sleep mode or fault conditions. Use Value: TO-126 metal tab allows direct heatsink mounting; 150°C TJ rating ensures reliability in under-hood thermal environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Darlington transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TIP122 | VCEO = 100 V, hFE ≥ 1000 @ IC = 3 A, same TO-126 package | Higher voltage headroom and gain; slightly higher VCE(sat) (≤3.0 V) | Preferred where >80 V transient immunity or >3 A peak load is required. |
| MJE702 | PNP complement; identical VCEO, IC, PC, and package; matched hFE and VCE(sat) | Used in complementary emitter-follower or push-pull output stages | Select when building symmetrical output drivers or H-bridge half-bridges requiring matched NPN/PNP characteristics. |
Compared with TIP122 and MJE702, the MJE802STU offers optimized balance of 80 V rating, 4 A capability, and integrated biasing for cost-sensitive industrial switching-making it ideal where exact 80 V operation and simplified layout are prioritized over maximum gain or complementary symmetry.
Availability
MJE802STU is available at Aetrix Electronics and suitable for relay drivers, DC motor controls, linear regulator pass elements, and power supply enable switches requiring stable component supply and long-term industrial availability.
Supply support for MJE802STU 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
ON Semiconductor (formerly Fairchild Semiconductor) is a global semiconductor supplier focused on energy-efficient electronics, with leadership in power management, analog, and discrete devices.
The MJE802STU belongs to the legacy MJE800-series Darlington transistor family, designed specifically for high-reliability industrial switching and linear amplification where integrated biasing, thermal robustness, and proven field longevity are critical.
FAQ
What is the maximum collector-emitter voltage rating for the MJE802STU?
The MJE802STU has a maximum collector-emitter voltage (VCEO) rating of 80 V at TC = 25°C. This rating is confirmed in the Absolute Maximum Ratings table and applies specifically to the MJE802 and MJE803 variants. Exceeding this voltage risks avalanche breakdown and permanent device failure. Derating is required above 25°C case temperature per the power derating curve in the datasheet.
Does the MJE802STU require external base resistors for operation?
No, the MJE802STU does not require external base resistors. It features monolithic construction with built-in base-emitter resistors (R1 ≈ 10 kΩ, R2 ≈ 0.6 kΩ), as shown in the equivalent circuit diagram. This internal network provides self-biasing, allowing direct connection to logic-level drivers. Adding external resistors may disrupt intended biasing and degrade performance of the MJE802STU.
What is the DC current gain (hFE) specification for the MJE802STU?
The MJE802STU guarantees a minimum DC current gain (hFE) of 750 at VCE = 3 V and IC = 1.5 A, as specified in the Electrical Characteristics table. This value applies to both MJE802 and MJE800 variants. Gain drops to ≥100 at IC = 4 A, reflecting typical Darlington behavior under full-rated current.
Which package type is used for the MJE802STU, and what are its thermal characteristics?
The MJE802STU uses the TO-126 package-a 3-lead, through-hole, thermally enhanced plastic package with a metal tab electrically connected to the collector. Its thermal resistance from junction-to-case (RθJC) is not explicitly listed, but the datasheet specifies 40 W maximum collector dissipation at TC = 25°C and full derating to zero at TC = 175°C. The metal tab must be mounted to a heatsink for reliable operation above ~1 W.
Is the MJE802STU pin-compatible with other devices in the MJE800 series?
Yes, the MJE802STU is pin-compatible with all members of the MJE800/801/802/803 family-including MJE800STU, MJE801STU, and MJE803STU-as they share identical TO-126 pinout (Emitter, Collector, Base) and mechanical dimensions. However, electrical ratings differ: MJE802STU and MJE803STU are rated for 80 V VCEO, while MJE800STU and MJE801STU are rated for 60 V. Substituting across voltage grades without circuit review may compromise reliability.
MJE802STU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-225AA, TO-126-3
- Packaging:
- Tube
- Product Status:
- Obsolete
- Transistor Type:
- NPN - Darlington
- Current - Collector (Ic) (Max):
- 4 A
- Voltage - Collector Emitter Breakdown (Max):
- 80 V
- Vce Saturation (Max) @ Ib, Ic:
- 2.5V @ 30mA, 1.5A
- Current - Collector Cutoff (Max):
- 100µA
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 750 @ 1.5A, 3V
- Power - Max:
- 40 W
- Frequency - Transition:
- -
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-126-3
MJE802STU FAQ
1.How can I place an order for MJE802STU through Aetrix?
Please submit a Request for Quotation (RFQ) for MJE802STU 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 MJE802STU reliable?
The price and inventory of MJE802STU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MJE802STU is usually 5 days.
3.What payment methods are accepted for MJE802STU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MJE802STU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MJE802STU?
MJE802STU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MJE802STU 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 MJE802STU?
For technical support, including MJE802STU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MJE802STU requirements.
6.How does Aetrix verify that MJE802STU is sourced from the original manufacturer or authorized distributors?
All MJE802STU 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 MJE802STU meets industry standards.
7.What is the process for return or replacement of MJE802STU?
All MJE802STU units undergo pre-shipment inspection (PSI). If there is an issue with MJE802STU, 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 MJE802STU part is unused and in its original packaging.
Return procedure for MJE802STU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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