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onsemi MSD42WT1
- Part No.:
- MSD42WT1
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- SC-70, SOT-323
- Datasheet:
-
MSD42WT1.pdf
- Description:
- TRANS NPN 300V 0.15A SC70-3
- Quantity:
- Payment:
- Shipping:
Inventory:9,034
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Product details
Overview
MSD42WT1 from onsemi is an NPN silicon planar transistor designed for high-voltage general-purpose amplifier applications, featuring 300 V collector-emitter and collector-base breakdown voltage, 150 mA continuous collector current, and 450 mW power dissipation in SC-70 (SOT-323) package. It serves as a robust switching and amplification device in low-power surface-mount circuits requiring high-voltage tolerance.
For engineers reviewing the MSD42WT1 datasheet, pinout, applications, or equivalent options, key selection criteria include V(BR)CEO = 300 V, IC = 150 mA, hFE = 25–40 (at IC = 1–30 mA), VCE(sat) ≤ 0.5 V (IC = 20 mA, IB = 2 mA), and AEC-Q101 qualification for automotive-grade reliability.
Technical Context
This NPN transistor operates with a maximum junction temperature of +150 °C and thermal resistance RJA = 274 °C/W on FR-4 board (10 mm², 1 oz Cu). Its DC current gain exhibits strong current dependency-hFE = 25 at IC = 1 mA and rises to 40 at IC = 30 mA-supporting both small-signal amplification and moderate-current switching.
Breakdown voltages are symmetrically rated: V(BR)CBO = V(BR)CEO = 300 V, confirming balanced high-voltage capability across collector-base and collector-emitter junctions. Cutoff currents remain tightly controlled: ICBO ≤ 0.1 µA at VCB = 200 V and IEBO ≤ 0.1 µA at VEB = 6.0 V, ensuring low leakage in high-impedance bias networks.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| V(BR)CEO | 300 V - Enables operation in 240 VAC-derived supply rails and flyback snubber circuits without breakdown. |
| IC (continuous) | 150 mA - Supports medium-current driver stages for relays, LEDs, or gate driving of small MOSFETs. |
| hFE (min–max) | 25–40 - Provides predictable DC bias stability across production lots at 1–30 mA operating range. |
| VCE(sat) | ≤ 0.5 V @ IC = 20 mA, IB = 2 mA - Minimizes conduction loss and self-heating in saturated-switch applications. |
| Package | SC-70 (SOT-323) - Surface-mount footprint (1.25 × 2.1 mm) compatible with automated assembly and space-constrained PCBs. |
| AEC-Q101 | Qualified - Meets stress-test requirements for automotive electronics including temperature cycling and HTRB. |
Pinout & Package
MSD42WT1 is housed in the SC-70 (SOT-323) package, a compact 3-pin surface-mount outline with gull-wing leads, optimized for low-power applications and reflow-compatible assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base | Control terminal for forward-biased injection; requires current-limited drive (IB ≈ IC/hFE) to ensure saturation. |
| 2 | Emitter | Common reference node; connected to ground or low-side return path in common-emitter configurations. |
| 3 | Collector | High-voltage output node; handles up to 300 V and 150 mA, suitable for inductive load switching. |
Key Features
| Feature | Design Value |
|---|---|
| Pb-Free, Halogen-Free, RoHS Compliant | Meets global environmental compliance mandates without compromising solderability or thermal performance. |
| AEC-Q101 Qualified | Validated for automotive underhood and infotainment systems per stress test requirements (HTOL, TC, HTRB). |
| High V(BR)CEO / V(BR)CBO | 300 V rating enables use in offline auxiliary supplies, relay drivers, and industrial sensor interface circuits. |
| Low VCE(sat) | ≤ 0.5 V reduces power loss and thermal rise in linear and saturated switching modes. |
Applications
| Automotive Interior Lighting Control | Industrial Sensor Signal Conditioning |
|---|---|
Use Scenario: Driving 12–24 V LED strings in dashboard backlighting and ambient lighting modules. IC Role / Device Role / Timing Role: NPN switch controlling current path to LED loads via microcontroller GPIO. Use Value: 300 V rating prevents failure during load dump transients; 150 mA capacity supports multi-LED parallel strings. | Use Scenario: Amplifying low-level analog outputs from pressure or temperature sensors before ADC sampling. IC Role / Device Role / Timing Role: Small-signal common-emitter amplifier stage with stable hFE across temperature. Use Value: hFE = 25–40 at 1–30 mA ensures consistent gain without external feedback compensation. |
| AC-DC Auxiliary Power Supply | Relay and Solenoid Interface Circuit |
Use Scenario: Regulating bias voltage in flyback converter auxiliary windings for control ICs. IC Role / Device Role / Timing Role: High-voltage pass transistor in shunt-regulated or series-regulated auxiliary rail. Use Value: V(BR)CEO = 300 V withstands reflected primary-side spikes; low leakage (ICBO ≤ 0.1 µA) maintains regulation accuracy. | Use Scenario: Interfacing microcontroller outputs to 12/24 V relay coils or solenoid actuators. IC Role / Device Role / Timing Role: Saturated switch providing galvanic isolation between logic and inductive load. Use Value: VCE(sat) ≤ 0.5 V limits coil drive loss; SC-70 package allows dense placement near MCU I/O headers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN high-voltage transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMBT4401LT1G | V(BR)CEO = 40 V, IC = 600 mA - lower voltage, higher current rating. | Not suitable for >100 V applications; better for low-voltage digital switching. | Select when operating below 40 V and higher current drive is needed. |
| NSVMSD42WT1G | Identical electrical specs; differentiated by NSV prefix indicating AEC-Q101 PPAP-capable automotive traceability. | Same functional use; required where automotive documentation and change control are mandated. | Choose NSVMSD42WT1G for Tier-1 automotive BOMs requiring full PPAP submission support. |
Compared with MMBT4401LT1G, MSD42WT1 delivers 7.5× higher voltage blocking but lower current handling; versus NSVMSD42WT1G, it shares identical silicon and packaging but lacks automotive-specific documentation controls-making it ideal for industrial and commercial designs where cost and availability are prioritized.
Availability
MSD42WT1 is available at Aetrix Electronics and suitable for automotive interior lighting control, industrial sensor signal conditioning, and AC-DC auxiliary power supply applications requiring stable component supply and long-term manufacturability.
Supply support for MSD42WT1 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, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The MSD42WT1 belongs to onsemi's high-voltage bipolar transistor product line, engineered specifically for reliable switching and amplification in space-constrained, high-reliability applications where voltage resilience and thermal stability are critical.
FAQ
What is the maximum collector-emitter voltage rating for MSD42WT1?
The MSD42WT1 has a guaranteed minimum V(BR)CEO rating of 300 V at IC = 1.0 mA and IB = 0. This high breakdown voltage makes MSD42WT1 suitable for circuits exposed to transient overvoltages, such as relay coil suppression, flyback snubbers, and auxiliary power supplies derived from 240 VAC mains.
Is MSD42WT1 qualified for automotive applications?
MSD42WT1 itself is not AEC-Q101 qualified; however, its automotive-grade variant NSVMSD42WT1G carries full AEC-Q101 qualification and PPAP capability. Engineers selecting MSD42WT1 for non-automotive industrial or commercial use benefit from identical electrical performance and SC-70 packaging without automotive documentation overhead.
What is the pin configuration of MSD42WT1 in the SC-70 package?
MSD42WT1 uses Style 3 pinout in SC-70 (SOT-323): Pin 1 = Base, Pin 2 = Emitter, Pin 3 = Collector. This configuration is confirmed in the official onsemi mechanical drawing CASE 419 STYLE 3 and matches the marking diagram shown in the datasheet.
What is the typical DC current gain (hFE) of MSD42WT1 at different operating points?
MSD42WT1 specifies hFE1 ≥ 25 at VCE = 10 V, IC = 1.0 mA and hFE2 ≥ 40 at VCE = 10 V, IC = 30 mA. The gain increases with collector current, supporting flexible bias design across small-signal and medium-current switching applications without requiring gain-stabilizing emitter degeneration.
Does MSD42WT1 have lead-free and RoHS-compliant packaging?
Yes, MSD42WT1G (the ordering part number) is Pb-free, halogen-free, and RoHS compliant per onsemi's standard manufacturing process. The "G" suffix explicitly denotes lead-free packaging, and the device meets EU RoHS Directive 2011/65/EU and related environmental regulations.
MSD42WT1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- SC-70, SOT-323
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 150 mA
- Voltage - Collector Emitter Breakdown (Max):
- 300 V
- Vce Saturation (Max) @ Ib, Ic:
- 500mV @ 2mA, 20mA
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 40 @ 30mA, 10V
- Power - Max:
- 150 mW
- Frequency - Transition:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SC-70-3 (SOT323)
MSD42WT1 FAQ
1.How can I place an order for MSD42WT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for MSD42WT1 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 MSD42WT1 reliable?
The price and inventory of MSD42WT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MSD42WT1 is usually 5 days.
3.What payment methods are accepted for MSD42WT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MSD42WT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MSD42WT1?
MSD42WT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MSD42WT1 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 MSD42WT1?
For technical support, including MSD42WT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MSD42WT1 requirements.
6.How does Aetrix verify that MSD42WT1 is sourced from the original manufacturer or authorized distributors?
All MSD42WT1 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 MSD42WT1 meets industry standards.
7.What is the process for return or replacement of MSD42WT1?
All MSD42WT1 units undergo pre-shipment inspection (PSI). If there is an issue with MSD42WT1, 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 MSD42WT1 part is unused and in its original packaging.
Return procedure for MSD42WT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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