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onsemi MJE172
- Part No.:
- MJE172
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-225AA, TO-126-3
- Datasheet:
-
MJE172.pdf
- Description:
- TRANS PNP 80V 3A TO-126
- Quantity:
- Payment:
- Shipping:
Inventory:2,386
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Product details
Overview
MJE172 from onsemi is a PNP silicon power transistor designed for low-power audio amplification and high-speed switching applications, with VCEO = 80 V, IC = 3.0 A continuous, and fT = 50 MHz. It operates in TO-225 package with annular construction for low leakage and meets UL 94 V-0 flammability rating.
For engineers reviewing the MJE172 datasheet, pinout, applications, or equivalent options, key selection criteria include its 80 V VCEO, 3.0 A collector current capability, 12.5 W case-rated power dissipation, complementary pairing with MJE182, and suitability for Class AB audio output stages and relay drivers.
Technical Context
The MJE172 is a discrete PNP bipolar junction transistor optimized for linear amplification and fast switching. Its high current-gain–bandwidth product (fT = 50 MHz) supports stable operation up to mid-RF frequencies under specified bias conditions (IC = 100 mA, VCE = 10 V), while its annular base construction minimizes leakage currents across temperature.
Thermal performance is defined by RJC = 10 °C/W and RJA = 83.4 °C/W, enabling reliable operation within −65 °C to +150 °C junction range. Safe operating area (SOA) curves confirm second-breakdown-limited behavior at high VCE, with thermally limited conduction below 50 V at full 3 A.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 80 Vdc - Maximum collector-emitter voltage before breakdown under open-base condition; defines safe DC rail headroom in amplifier or switch designs. |
| IC (continuous) | 3.0 Adc - Continuous collector current rating at TC = 25 °C; determines maximum sustained load-handling capacity in driver circuits. |
| PD @ TC = 25 °C | 12.5 W - Maximum power dissipation with heatsink attached; sets thermal design baseline for PCB-mounted heatsinking solutions. |
| fT | 50 MHz - Current-gain–bandwidth product at IC = 100 mA, VCE = 10 V; indicates usable small-signal bandwidth for audio and switching applications. |
| hFE (min) | 12 - Minimum DC current gain at IC = 1.5 A, VCE = 1.0 V; ensures predictable base drive requirements in saturated switching configurations. |
| VCE(sat) | 1.7 Vdc - Collector-emitter saturation voltage at IC = 3.0 A, IB = 600 mA; directly impacts conduction loss and thermal rise in on-state operation. |
| RJC | 10 °C/W - Junction-to-case thermal resistance; enables accurate heatsink sizing when mounting to metal chassis or extruded aluminum. |
Pinout & Package
Package: TO-225 (Case 77-09, Style 1), plastic-encapsulated, Pb-free, UL 94 V-0 compliant. Mounting tab is electrically connected to collector.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Emitter | Main current exit path; referenced to base for bias control; polarity defines PNP operation (current flows into collector, out emitter). |
| 2, 4 | Collector | Main current entry path and thermal interface; pins 2 and 4 are internally bonded to the metal tab for enhanced heat transfer and electrical connection. |
| 3 | Base | Control terminal; requires ~1.5–2.0 V forward bias (VBE(sat)) to fully saturate; base current must be ≥ IC/hFE(min) for reliable switching. |
Key Features
| Feature | Design Value |
|---|---|
| High DC current gain | hFE ≥ 50 at IC = 100 mA enables low-base-drive designs in linear amplifiers and low-power switches. |
| High fT | 50 MHz bandwidth supports clean square-wave switching up to ~5 MHz and wideband audio fidelity without phase roll-off. |
| Annular construction | Reduces ICBO and IEBO to ≤ 0.1 mA, improving stability in high-impedance bias networks and high-temperature environments. |
| TO-225 mechanical robustness | 14.5–16.63 mm body length and 10.6–11.1 mm width support standard clip-mount heatsinks and automated through-hole assembly. |
| Pb-free & RoHS compliance | G-suffix confirms lead-free termination and halogen-free epoxy, satisfying IPC-J-STD-020 reflow and environmental compliance requirements. |
Applications
| Audio Power Amplifier Stage | DC Motor / Relay Driver |
|---|---|
|
Use Scenario: Output stage in Class AB low-power audio amplifiers driving 4–8 Ω speakers up to 5 W RMS. IC Role / Device Role / Timing Role: PNP complement to NPN MJE182 in push-pull configuration; handles negative half-cycle conduction with matched SOA and gain. Use Value: Delivers 80 V VCEO and 3 A IC to support rail voltages up to ±40 V, minimizing crossover distortion while maintaining thermal safety margin. |
Use Scenario: High-side switch controlling 12–24 V DC loads such as relays, solenoids, or small fans in industrial control panels. IC Role / Device Role / Timing Role: Saturated PNP switch with base-driven turn-on; used with pull-up resistor or logic-level driver to invert control signal polarity. Use Value: VCE(sat) ≤ 1.7 V at 3 A ensures <2.5 W conduction loss, reducing heatsink requirements versus lower-voltage alternatives. |
| Low-Current Switching Supply | Signal-Level Level Shifter |
|
Use Scenario: Pass transistor in linear post-regulator or low-current flyback auxiliary supply (<500 mA) requiring fast transient response. IC Role / Device Role / Timing Role: Series pass element controlled via error amplifier feedback; leverages high fT for loop stability at >10 kHz. Use Value: 50 MHz fT and low Cob = 60 pF enable stable compensation without excessive phase lag, supporting tight regulation under dynamic load steps. |
Use Scenario: Bidirectional level translation between 3.3 V microcontroller GPIO and 5–12 V legacy sensor or actuator interfaces. IC Role / Device Role / Timing Role: Emitter-follower configured as active pull-down with base biased to reference voltage; provides current gain and voltage inversion. Use Value: hFE ≥ 30 at 500 mA ensures minimal base current loading on MCU pins while sustaining ≥10 mA sink capability at output. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP power transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MJE171G | VCEO = 60 V, VCE(sat) ≤ 0.9 V at 1.5 A, fT = 50 MHz - lower voltage rating but lower saturation voltage. | Suitable for ≤±30 V rails; preferred where lower conduction loss at medium current is prioritized over voltage headroom. | Select MJE171G when operating below 60 V and optimizing for efficiency at 1–2 A; not drop-in for 80 V designs. |
| BD140 | VCEO = 80 V, IC = 1.5 A, PD = 12.5 W - same voltage rating but half the current capability and different pinout (E-B-C). | Acceptable for <1.5 A loads; requires PCB layout revision due to reversed emitter/base pin assignment. | Choose BD140 only if current demand is ≤1.5 A and board redesign is feasible; verify SOA curves match thermal constraints. |
Compared with MJE171G and BD140, the MJE172 offers the highest VCEO in its family and full 3 A current handling in TO-225, making it uniquely suited for 80 V rail applications demanding both voltage margin and sustained current delivery without derating.
Availability
MJE172 is available at Aetrix Electronics and suitable for low-power audio amplifiers, relay drivers, and linear regulator pass elements requiring stable component supply, long-term obsolescence management, and RoHS-compliant sourcing.
Supply support for MJE172 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 manufacturer specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.
The MJE172 belongs to the MJE170/180 series of complementary silicon power transistors, engineered specifically for low-distortion audio amplification and high-reliability, high-speed switching in cost-sensitive industrial controls.
FAQ
What is the maximum collector-emitter voltage rating for the MJE172?
The MJE172 has a guaranteed VCEO rating of 80 Vdc under open-base conditions, verified per onsemi's datasheet Rev. 14. This rating defines the absolute maximum DC voltage that can be applied between collector and emitter without risk of avalanche breakdown, and must be respected in all circuit designs using the MJE172.
Can the MJE172 be used as a direct replacement for the MJE171G?
No, the MJE172 is not a direct replacement for the MJE171G due to differences in voltage ratings: MJE172 specifies VCEO = 80 V and VCB = 100 V, whereas MJE171G is rated at VCEO = 60 V and VCB = 80 V. Substituting MJE172 into an MJE171G-design may be safe, but substituting MJE171G into an MJE172-design risks overvoltage failure. The MJE172 also exhibits higher VCE(sat) at full current.
What is the thermal resistance from junction to case for the MJE172?
The MJE172 has a maximum thermal resistance of RJC = 10 °C/W, measured from junction to the mounting surface of the TO-225 package. This value is critical for heatsink sizing when the device is operated near its 12.5 W case-rated power limit, and assumes proper mechanical mounting with thermal interface material.
Does the MJE172 have a built-in protection diode or ESD structure?
No, the MJE172 is a bare bipolar junction transistor without integrated protection diodes or ESD structures beyond its inherent HBM rating of Class 3B (≥8 kV). External flyback diodes must be added in inductive switching applications, and board-level ESD protection should be implemented per IEC 61000-4-2 requirements when used in exposed interfaces.
What is the minimum DC current gain (hFE) of the MJE172 at 1.5 A collector current?
The MJE172 guarantees hFE ≥ 12 at IC = 1.5 A, VCE = 1.0 V, and TC = 25 °C, as specified in the "ON CHARACTERISTICS" table of the official datasheet. This minimum gain determines the required base drive current-e.g., ≥125 mA base current is needed to sustain 1.5 A collector current reliably.
MJE172 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-225AA, TO-126-3
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Transistor Type:
- PNP
- Current - Collector (Ic) (Max):
- 3 A
- Voltage - Collector Emitter Breakdown (Max):
- 80 V
- Vce Saturation (Max) @ Ib, Ic:
- 1.7V @ 600mA, 3A
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 50 @ 100mA, 1V
- Power - Max:
- 1.5 W
- Frequency - Transition:
- 50MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-126
MJE172 FAQ
1.How can I place an order for MJE172 through Aetrix?
Please submit a Request for Quotation (RFQ) for MJE172 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 MJE172 reliable?
The price and inventory of MJE172 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MJE172 is usually 5 days.
3.What payment methods are accepted for MJE172?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MJE172 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MJE172?
MJE172 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MJE172 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 MJE172?
For technical support, including MJE172 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MJE172 requirements.
6.How does Aetrix verify that MJE172 is sourced from the original manufacturer or authorized distributors?
All MJE172 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 MJE172 meets industry standards.
7.What is the process for return or replacement of MJE172?
All MJE172 units undergo pre-shipment inspection (PSI). If there is an issue with MJE172, 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 MJE172 part is unused and in its original packaging.
Return procedure for MJE172:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MJE172 Tags
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