My Inquiry
My Account
onsemi MJE801STU
- Part No.:
- MJE801STU
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-225AA, TO-126-3
- Datasheet:
-
MJE801STU.pdf
- Description:
- TRANS NPN DARL 60V 4A TO-126-3
- Quantity:
- Payment:
- Shipping:
Inventory:5,391
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MJE801STU from ON Semiconductor (formerly Fairchild) is an NPN epitaxial silicon Darlington transistor in TO-126 package, rated for 60 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 switching applications such as relay drivers and power supply control circuits.
For engineers reviewing the MJE801STU datasheet, pinout, applications, or equivalent options, key selection criteria include verified DC current gain (hFE ≥ 750 @ IC = 1.5 A), collector-emitter saturation voltage (VCE(sat) ≤ 2.8 V @ IC = 2 A, IB = 40 mA), thermal derating behavior, and monolithic Darlington construction with integrated biasing resistors.
Technical Context
The MJE801STU implements a monolithic Darlington pair with on-chip base-emitter resistors (R1 ≈ 10 kΩ, R2 ≈ 0.6 kΩ) to provide self-biasing and reduce external component count. It delivers high DC current gain (hFE ≥ 750 at IC = 1.5 A) while maintaining low VBE(on) (≤ 2.5 V) under typical operating conditions.
Its safe operating area (SOA) supports pulsed operation up to 1000 V·A at 100 µs, with thermal resistance RθJC of 0.625 °C/W enabling stable 40 W dissipation at TC = 25°C. Junction temperature is rated to 150°C, with storage range from –55°C to +150°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 60 V - Maximum collector-emitter voltage before breakdown under open-base condition; defines upper limit for switching voltage rails. |
| IC | 4 A - Continuous collector current rating; supports medium-power load switching without forced cooling. |
| PC | 40 W - Maximum power dissipation at case temperature 25°C; requires heatsinking above ~25°C ambient. |
| hFE | ≥750 @ IC = 1.5 A - High DC current gain reduces required base drive current, easing microcontroller interface. |
| VCE(sat) | ≤2.8 V @ IC = 2 A, IB = 40 mA - Low saturation voltage minimizes conduction loss in linear and switching modes. |
| R1 / R2 | ≈10 kΩ / ≈0.6 kΩ - Integrated base-emitter resistors enable single-resistor biasing and improve turn-off speed vs. standard Darlingtons. |
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. Case material: UL 94 V-0 rated thermoplastic.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Emitter terminal of Darlington pair | Common emitter node; connects to ground or low-side return path; carries full load current. |
| 2 (Collector) | Collector terminal of Darlington pair | High-current output node; connects to load and supply rail; electrically isolated from mounting tab. |
| 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 built-in bias resistors | Eliminates need for external base resistors, reducing BOM count and PCB footprint while improving turn-off consistency. |
| High hFE ≥ 750 @ IC = 1.5 A | Enables direct drive from low-current sources (e.g., MCU GPIO), reducing driver-stage complexity. |
| VCE(sat) ≤ 2.8 V @ IC = 2 A | Limits conduction loss to ≤5.6 W at 2 A, supporting efficient thermal management in compact designs. |
| TO-126 package with metal tab | Provides mechanical robustness and direct heatsink attachment via mounting hole; RθJC = 0.625 °C/W enables high-power operation. |
Applications
| Relay Driver Circuits | DC Motor Control (Low-Voltage) |
|---|---|
Use Scenario: Driving 12–24 V electromagnetic relays in industrial PLC I/O modules and HVAC controllers. IC Role / Device Role / Timing Role: High-gain switch amplifying microcontroller GPIO signals to energize relay coils drawing up to 4 A peak. Use Value: Built-in R1/R2 ensures reliable turn-on/turn-off without external components; VCE(sat) ≤ 2.8 V keeps coil power loss low and contact life long. | Use Scenario: Controlling brushed DC motors in battery-powered tools and automotive auxiliary systems (e.g., window lift, seat adjust). IC Role / Device Role / Timing Role: Low-side switch regulating motor current in PWM or on/off mode at ≤60 V supply. Use Value: 4 A IC rating handles stall currents; SOA curve supports 100 µs pulse peaks up to 1000 V·A for transient suppression. |
| Linear Power Supply Pass Transistor | Overcurrent Protection Switch |
Use Scenario: Series pass element in adjustable 3–24 V, 3 A linear regulators for lab bench supplies and analog instrumentation. IC Role / Device Role / Timing Role: Voltage-controlled current source operating in active region with fixed base bias. Use Value: High hFE simplifies feedback loop design; 150°C TJ rating allows sustained operation under thermal stress. | Use Scenario: Current-limiting switch in power distribution units (PDUs) and smart fuses for 12–48 V DC systems. IC Role / Device Role / Timing Role: Fast-acting overcurrent cutoff triggered by sense resistor feedback into base. Use Value: Low VBE(on) (≤2.5 V) enables precise trip threshold setting; TO-126 tab allows direct thermal monitoring for foldback protection. |
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, no integrated R2; higher VCE(sat) (≤3.0 V) | Better suited for higher-voltage switching (>60 V); lacks built-in R2, requiring external base resistor for stable turn-off. | Select when higher breakdown voltage is critical and external biasing is acceptable. |
| BD679 | VCEO = 80 V, IC = 4 A, hFE ≥ 750 @ IC = 2 A, TO-126, no integrated resistors | Higher VCEO than MJE801STU but requires discrete base network; lower thermal resistance (RθJC = 0.5 °C/W). | Choose when 80 V rating is needed and board space allows external biasing components. |
Compared with TIP122 and BD679, the MJE801STU uniquely integrates both R1 and R2 for simplified single-resistor drive and improved switching consistency, making it optimal for cost-sensitive, space-constrained relay and motor control where 60 V operation suffices.
Availability
MJE801STU is available at Aetrix Electronics and suitable for relay driver circuits, low-voltage DC motor control, and linear power supply pass applications requiring stable component supply, long-term obsolescence mitigation, and traceable sourcing.
Supply support for MJE801STU 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 (acquired Fairchild Semiconductor in 2016) is a global supplier of energy-efficient semiconductor solutions for automotive, industrial, cloud computing, and IoT applications.
The MJE801STU belongs to Fairchild's legacy bipolar power transistor family designed for high-reliability, medium-power linear and switching applications where integrated biasing and proven ruggedness are essential.
FAQ
What is the maximum continuous collector current rating for MJE801STU?
The MJE801STU is rated for 4 A continuous collector current (IC) at case temperature TC = 25°C. Derating is required above 25°C per the published power derating curve (–0.32 W/°C above 25°C). At TC = 100°C, the usable IC drops to approximately 2.2 A to maintain safe junction temperature.
Does MJE801STU have built-in base resistors, and what are their values?
Yes, the MJE801STU features monolithic integration of two base-emitter resistors: R1 ≈ 10 kΩ (base-to-input) and R2 ≈ 0.6 kΩ (base-to-emitter). These enable single-resistor biasing, improve turn-off speed versus standard Darlingtons, and reduce external component count in relay and motor driver designs using MJE801STU.
What is the collector-emitter saturation voltage of MJE801STU under typical operating conditions?
The MJE801STU exhibits VCE(sat) ≤ 2.8 V when operated at IC = 2 A and IB = 40 mA, with VCE = 3 V. This value is confirmed in the official datasheet's Electrical Characteristics table and directly impacts conduction losses-e.g., 5.6 W at 2 A-guiding heatsink selection for MJE801STU-based designs.
Can MJE801STU be used as a direct replacement for MJE800STU?
No, MJE801STU is not a direct replacement for MJE800STU. While both share the same TO-126 package and built-in resistors, MJE800STU is rated for VCEO = 60 V and hFE ≥ 750 @ IC = 1.5 A, whereas MJE801STU has identical ratings but differs in internal gain binning and test conditions. Substitution requires verification of circuit margin against VCEO, hFE, and VCE(sat) specs for MJE801STU.
What is the junction-to-case thermal resistance (RθJC) of MJE801STU?
The junction-to-case thermal resistance RθJC of MJE801STU is 0.625 °C/W, derived from its 40 W power dissipation rating at TC = 25°C and 150°C maximum junction temperature. This value is critical for heatsink sizing and must be combined with RθCS and RθSA to calculate total thermal path for MJE801STU in high-power applications.
MJE801STU 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):
- 60 V
- Vce Saturation (Max) @ Ib, Ic:
- 2.8V @ 40mA, 2A
- Current - Collector Cutoff (Max):
- 100µA
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 750 @ 2A, 3V
- Power - Max:
- 40 W
- Frequency - Transition:
- -
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-126-3
MJE801STU FAQ
1.How can I place an order for MJE801STU through Aetrix?
Please submit a Request for Quotation (RFQ) for MJE801STU 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 MJE801STU reliable?
The price and inventory of MJE801STU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MJE801STU is usually 5 days.
3.What payment methods are accepted for MJE801STU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MJE801STU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MJE801STU?
MJE801STU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MJE801STU 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 MJE801STU?
For technical support, including MJE801STU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MJE801STU requirements.
6.How does Aetrix verify that MJE801STU is sourced from the original manufacturer or authorized distributors?
All MJE801STU 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 MJE801STU meets industry standards.
7.What is the process for return or replacement of MJE801STU?
All MJE801STU units undergo pre-shipment inspection (PSI). If there is an issue with MJE801STU, 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 MJE801STU part is unused and in its original packaging.
Return procedure for MJE801STU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MJE801STU Tags
-
MMBT3906LT1G
onsemi
-
MMBT3904-7-F
Diodes Incorporated
-
MMBT3904LT1G
onsemi
-
MMBT3906-7-F
Diodes Incorporated
-
MMBT3904-TP
Micro Commercial Co
-
MMBT2222A-7-F
Diodes Incorporated
-
BC846BLT1G
onsemi
-
BC847B,215
Nexperia USA Inc.
-
SMMBT3904LT1G
onsemi
-
MMBT2222A-TP
Micro Commercial Co
-
MMBTA06LT1G
onsemi
-
MMBT2222ALT1G
onsemi
Tech Hub
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
