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Infineon Technologies SMBTA 42 E6433
- Part No.:
- SMBTA 42 E6433
- Manufacturer:
- Infineon Technologies
- Category:
- Single Bipolar Transistors
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
SMBTA 42 E6433.pdf
- Description:
- TRANS NPN 300V 0.5A PG-SOT23
- Quantity:
- Payment:
- Shipping:
Inventory:3,468
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Product details
Overview
SMBTA42 E6433 from Infineon Technologies is an NPN silicon high-voltage transistor in SOT-23 package, rated for 300 V VCEO, 500 mA IC, and 360 mW Ptot at TS ≤ 74 °C; designed for high-voltage switching in automotive lighting control, flyback snubber circuits, and industrial relay drivers.
For engineers reviewing the SMBTA42 E6433 datasheet, SMBTA42 E6433 pinout, SMBTA42 E6433 application, or SMBTA42 E6433 equivalent, key selection criteria include VCEO = 300 V, hFE ≥ 25 @ IC = 1 mA, VCE(sat) ≤ 0.5 V @ IC = 20 mA/IB = 2 mA, fT ≥ 50 MHz, and AEC-Q101 qualification for automotive-grade reliability.
Technical Context
This discrete NPN bipolar junction transistor operates in linear or saturated switching mode with a maximum junction temperature of 150 °C and thermal resistance RthJS ≤ 210 K/W. Its high VCEO and VCBO (both 300 V) support robust operation in inductive load switching where voltage spikes exceed standard 60–80 V transistors.
The device features low saturation voltage (VCE(sat) ≤ 0.5 V), complementary pairing with SMBTA92 (PNP), and RoHS-compliant SOT-23 packaging. Its fT of 50–70 MHz enables moderate-frequency switching up to ~10 MHz under specified bias conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 300 V - supports switching of 230 VAC-derived rails and flyback clamp voltages without breakdown |
| IC | 500 mA - sufficient for driving small relays, LED strings, or gate resistors in MOSFET-based converters |
| VCE(sat) | ≤ 0.5 V @ IC = 20 mA / IB = 2 mA - minimizes conduction loss in saturated-switch applications |
| hFE | 25–100 - provides stable current amplification across IC = 1–30 mA, enabling predictable base drive design |
| fT | 50–70 MHz - allows use in low-MHz switching regulators and pulse generators with adequate gain margin |
| RthJS | ≤ 210 K/W - defines thermal path from junction to solder point; requires PCB copper area for safe 360 mW dissipation |
| AEC-Q101 | Qualified - validated for automotive applications including under-hood temperature cycling and humidity testing |
Pinout & Package
Package: SOT-23 (TO-236AB), surface-mount, 3-pin plastic case with gull-wing leads. Marking "s1D" identifies SMBTA42 variant on top surface.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | E | Current sink node; connects to ground or low-side return path; must be routed with low-inductance trace in switching apps |
| 2 (Base) | B | Control input; requires current-limited drive (IB ≤ 100 mA) to avoid secondary breakdown during fast turn-on |
| 3 (Collector) | C | High-voltage output node; connects to inductive load or supply rail; requires snubbing when switching reactive loads |
Key Features
| Feature | Design Value |
|---|---|
| High-voltage blocking | 300 V VCEO/VCBO enables direct interface with 230 VAC rectified rails and flyback transformer primary clamping |
| Low saturation voltage | VCE(sat) ≤ 0.5 V reduces power loss and self-heating in continuous conduction mode switching |
| AEC-Q101 qualification | Validated for automotive under-hood environments including temperature cycling, mechanical shock, and humidity exposure |
| Complementary PNP pair | SMBTA92 offers matched characteristics for push-pull or H-bridge driver stages requiring bipolar symmetry |
| Pb-free & RoHS compliant | Meets EU Directive 2011/65/EU; compatible with lead-free reflow profiles (peak ≤ 260 °C) |
Applications
| Automotive LED Headlamp Driver | Industrial Relay Interface |
|---|---|
Use Scenario: Switching 12–24 V LED arrays in adaptive front-lighting systems with PWM dimming. IC Role / Device Role / Timing Role: High-side or low-side switch controlling current flow through LED string; operates in saturated mode with <1 µs turn-off delay. Use Value: 300 V rating prevents failure during load dump transients; low VCE(sat) maintains efficiency >92% at 350 mA. | Use Scenario: Driving 24 VDC coil of industrial control relays in PLC I/O modules. IC Role / Device Role / Timing Role: Discrete BJT switch replacing optocoupler-driven MOSFETs; handles 500 mA inductive surge with flyback diode integration. Use Value: AEC-Q101 qualification ensures reliability over 100,000 cycles at 85 °C ambient; RthJS ≤ 210 K/W supports compact PCB layout. |
| Flyback Converter Snubber | AC Mains Voltage Detection |
Use Scenario: Clamping voltage spikes across transformer primary windings in offline SMPS. IC Role / Device Role / Timing Role: Fast-turn-off NPN clamp transistor triggered by RC network; absorbs energy during MOSFET off-time. Use Value: fT ≥ 50 MHz ensures sub-100 ns response; 300 V rating withstands reflected spikes up to 280 V. | Use Scenario: Resistive-divider-based zero-crossing detection in smart metering and AC dimmer ICs. IC Role / Device Role / Timing Role: Linear-region amplifier converting scaled mains voltage to logic-level signal; biased at IC = 100 µA. Use Value: hFE ≥ 25 at low current ensures stable gain; VBREBO = 6 V protects base-emitter junction from overvoltage. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-voltage NPN switching applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMBTA42 | Identical electrical specs; same die in smaller SOT-23-3L footprint with tighter pitch (0.65 mm vs 0.95 mm) | Preferred for space-constrained PCBs; identical thermal derating but lower RthJA due to thinner mold compound | Select when board real estate is critical and assembly process supports fine-pitch SMT placement |
| ZTX653 | Higher VCEO = 350 V, higher Ptot = 1 W, TO-92 package; hFE min = 100 @ IC = 10 mA | Used in higher-power analog amplifiers and linear regulators; not AEC-Q101 qualified | Choose only for non-automotive, higher-power linear applications where SOT-23 thermal limits are exceeded |
Compared with MMBTA42, SMBTA42 E6433 offers identical performance with legacy SOT-23 pad compatibility; versus ZTX653, it trades power handling and gain for automotive qualification and surface-mount scalability.
Availability
SMBTA42 E6433 is available at Aetrix Electronics and suitable for automotive lighting control, industrial relay interfacing, and flyback snubber circuits requiring stable component supply with AEC-Q101 assurance and long-term production continuity.
Supply support for SMBTA42 E6433 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
Infineon Technologies AG is a German semiconductor manufacturer specializing in power management, automotive electronics, and industrial control ICs and discrete devices.
The SMBTA42 belongs to Infineon's high-voltage bipolar transistor product line, engineered specifically for automotive and industrial switching applications demanding robustness against voltage transients and extended temperature operation.
FAQ
Is SMBTA42 E6433 pin-compatible with MMBTA42?
Yes - both share identical SOT-23 pinout (Emitter-Base-Collector on pins 1-2-3) and identical electrical specifications. The MMBTA42 uses a slightly narrower lead pitch (0.65 mm vs 0.95 mm), but footprint compatibility is maintained per JEDEC MO-178AA. No PCB redesign is needed for drop-in replacement.
What is the maximum safe operating frequency for SMBTA42 E6433 in switching mode?
The transition frequency fT is 50–70 MHz, but practical switching frequency is limited by storage time (ts) and saturation recovery. For reliable hard-switching, keep fSW ≤ 1–2 MHz with active base pull-down. At 100 kHz, it achieves full saturation with <500 ns turn-off delay under IC = 100 mA conditions.
Can SMBTA42 E6433 replace BC548 in high-voltage applications?
No - BC548 has VCEO = 30 V and is unsuitable above 50 V. SMBTA42 E6433 is rated for 300 V and designed for high-voltage snubbing, relay driving, and AC line sensing where BC548 would fail catastrophically. Their base drive requirements also differ significantly due to hFE variation.
Does SMBTA42 E6433 require a heatsink in typical operation?
No - its 360 mW Ptot rating at TS ≤ 74 °C is managed via PCB copper thermal relief. With ≥ 1 cm² of 1-oz copper connected to emitter pad, junction temperature stays below 120 °C at full 500 mA DC. Heatsinks are unnecessary unless ambient exceeds 85 °C or pulsed operation exceeds 50% duty cycle.
SMBTA 42 E6433 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Infineon Technologies
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 500 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:
- 360 mW
- Frequency - Transition:
- 70MHz
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- PG-SOT23
SMBTA 42 E6433 FAQ
1.How can I place an order for SMBTA 42 E6433 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBTA 42 E6433 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 SMBTA 42 E6433 reliable?
The price and inventory of SMBTA 42 E6433 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBTA 42 E6433 is usually 5 days.
3.What payment methods are accepted for SMBTA 42 E6433?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBTA 42 E6433 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBTA 42 E6433?
SMBTA 42 E6433 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBTA 42 E6433 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 SMBTA 42 E6433?
For technical support, including SMBTA 42 E6433 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBTA 42 E6433 requirements.
6.How does Aetrix verify that SMBTA 42 E6433 is sourced from the original manufacturer or authorized distributors?
All SMBTA 42 E6433 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 SMBTA 42 E6433 meets industry standards.
7.What is the process for return or replacement of SMBTA 42 E6433?
All SMBTA 42 E6433 units undergo pre-shipment inspection (PSI). If there is an issue with SMBTA 42 E6433, 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 SMBTA 42 E6433 part is unused and in its original packaging.
Return procedure for SMBTA 42 E6433:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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