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Taiwan Semiconductor Corporation SMBJ40H
- Part No.:
- SMBJ40H
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ40H.pdf
- Description:
- 600W, 49.4V, 10%, UNIDIRECTIONAL
- Quantity:
- Payment:
- Shipping:
Inventory:8,052
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Product details
Overview
SMBJ40H from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for automotive-grade ESD and surge protection in power rails and signal lines. It features a 40 V working stand-off voltage (VWM), 44.4–54.3 V breakdown voltage (VBR), 71.4 V maximum clamping voltage (VC) at 8.8 A peak pulse current, and 600 W peak pulse power rating with <1.0 ps response time. It is AEC-Q101 qualified and meets ISO 7637-2 Pulse 1/2a/2b/3a/3b for automotive load-dump and inductive switching immunity.
For engineers reviewing the SMBJ40H datasheet, SMBJ40H pinout, SMBJ40H application, or SMBJ40H equivalent, key selection criteria include clamping performance under 10/1000 µs transients, unidirectional polarity marking, DO-214AA (SMB) package compatibility with automated SMT placement, and compliance with automotive EMC requirements including electrical fast transient (EFT) immunity.
Technical Context
The SMBJ40H operates as a unidirectional avalanche diode, conducting only when reverse voltage exceeds its breakdown threshold to shunt transient energy to ground. Its glass-passivated junction ensures stable VBR tolerance (±10% typical) and low leakage (<1 µA at 40 V), while its thermal resistance (RθJA = 55 °C/W) supports operation up to 150 °C junction temperature in compact PCB layouts.
It is rated for non-repetitive 10/1000 µs surge pulses per ANSI/IEEE C62.35, with derating above 25 °C ambient per Fig. 2. The device is not intended for bidirectional use - bipolar variants require CH or CAH suffixes (e.g., SMBJ40CH); SMBJ40H is strictly unidirectional with cathode band marking.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 40 V - Maximum continuous DC or RMS voltage the device blocks without conduction |
| VBR min/max | 44.4 V / 54.3 V - Breakdown occurs within this range at 1 mA test current; defines turn-on threshold |
| VC @ IPP | 71.4 V at 8.8 A - Clamped voltage during 10/1000 µs surge; limits downstream IC stress |
| PPK | 600 W - Peak pulse power handling capability for single transient events |
| IR @ VWM | <1 µA - Low leakage preserves system efficiency and battery life in always-on circuits |
| Package | DO-214AA (SMB) - Standard surface-mount outline compatible with IPC-7351B footprint and reflow profiles |
| AEC-Q101 | Qualified - Validated for automotive applications including temperature cycling, humidity, and mechanical shock |
Pinout & Package
DO-214AA (SMB) package: molded plastic case with matte tin-plated leads, polarity indicated by cathode band on one end. Weight ≈ 0.090 g. Meets UL 94V-0 flammability and JESD201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to protected line (e.g., 12 V rail); conducts during forward surges (rare) |
| Cathode | Reverse conduction terminal | Connected to ground; avalanches to clamp transients when line voltage exceeds VBR |
| Cathode band | Polarity indicator | Visible marking on package body; confirms unidirectional orientation for correct PCB layout |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive under-hood and infotainment systems requiring reliability across -55 °C to +150 °C |
| Glass-passivated junction | Ensures stable VBR over lifetime and resistance to moisture-induced parameter drift |
| Fast response time <1.0 ps | Clamps ESD events before sensitive logic or analog circuitry sustains damage |
| ISO 7637-2 compliance | Withstands standardized automotive transients including load dump (Pulse 5) and inductive switch-off (Pulse 1/2a/2b) |
| RoHS & halogen-free | Meets IEC 61249-2-21 and EU directives for environmentally compliant manufacturing and recycling |
Applications
| Automotive Power Rail Protection | Industrial Sensor Interface Protection |
|---|---|
Use Scenario: 12 V battery-fed ECUs exposed to load dump and alternator ripple. IC Role / Device Role: Unidirectional TVS placed between power input and ground to clamp surges before LDOs or microcontrollers. Use Value: Limits transient voltage to ≤71.4 V, protecting downstream 3.3 V/5 V logic from damage during ISO 7637-2 Pulse 5 (load dump). | Use Scenario: 4–20 mA current loop sensors in factory automation subject to EFT bursts. IC Role / Device Role: TVS on sensor supply line to absorb 5 kHz EFT noise and prevent false triggering of ADC inputs. Use Value: Sub-1 ps response ensures clamping before EFT edge reaches analog front-end, preserving measurement integrity. |
| LED Lighting Driver Protection | Automotive CAN Bus Line Protection |
Use Scenario: Constant-current LED drivers in vehicle exterior lighting subjected to inductive kickback. IC Role / Device Role: TVS across driver output to suppress flyback voltage from relay or solenoid switching. Use Value: 600 W PPK rating handles repetitive 10/1000 µs spikes without degradation, extending driver lifespan. | Use Scenario: CAN H/L lines in body control modules exposed to board-level ESD and cable coupling. IC Role / Device Role: Unidirectional TVS on CAN_H to ground (with separate TVS on CAN_L) for asymmetric surge suppression. Use Value: Low leakage (<1 µA) avoids CAN bus bias current errors; clamping at 71.4 V prevents transceiver latch-up. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ40A | Narrower VBR range (44.4–49.1 V) vs. SMBJ40H (44.4–54.3 V); tighter tolerance improves predictability in precision clamping | Preferred where consistent clamping onset is critical (e.g., regulated 3.3 V supply rails) | Select SMBJ40A if VBR consistency matters more than absolute max clamping margin |
| SMCJ40A | Larger DO-214AB (SMC) package; higher PPK (1500 W) but same VWM/VBR specs; RθJA = 35 °C/W vs. 55 °C/W | Suitable for higher-energy transients or thermally constrained designs needing lower junction rise | Choose SMCJ40A only when 600 W is insufficient or thermal headroom is limited |
Compared with SMBJ40H, SMBJ40A offers tighter VBR control for repeatable clamping onset, while SMCJ40A provides greater surge energy handling and better thermal dissipation - both require PCB footprint changes and are not drop-in replacements.
Availability
SMBJ40H is available at Aetrix Electronics and suitable for automotive electronics, industrial sensor interfaces, LED lighting drivers, and CAN bus protection requiring stable component supply across extended temperature ranges and high-reliability production cycles.
Supply support for SMBJ40H 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
Taiwan Semiconductor Corporation (TSC) is a vertically integrated semiconductor manufacturer specializing in discrete power devices, TVS diodes, rectifiers, and MOSFETs, with global distribution and AEC-Q101 validation capabilities.
The SMBJH series was developed specifically for automotive and industrial transient suppression, emphasizing robustness against ISO 7637-2 pulses, low leakage, and automated assembly compatibility in DO-214AA packaging.
FAQ
What is the maximum clamping voltage of SMBJ40H under standard 10/1000 µs surge conditions?
The SMBJ40H has a maximum clamping voltage (VC) of 71.4 V at 8.8 A peak pulse current (IPP), measured using the standardized 10/1000 µs waveform. This value ensures downstream components see no more than 71.4 V during transient events, making SMBJ40H suitable for protecting 48 V nominal systems and 3.3 V/5 V logic rails with appropriate design margin.
Is SMBJ40H bidirectional or unidirectional, and how is polarity marked?
SMBJ40H is a unidirectional TVS diode. Polarity is marked by a cathode band on the DO-214AA (SMB) package body - the banded end connects to ground, and the opposite end connects to the protected line. Bidirectional variants require CH or CAH suffixes (e.g., SMBJ40CH); SMBJ40H must not be used in bipolar configurations.
Does SMBJ40H meet automotive qualification standards?
Yes, SMBJ40H is AEC-Q101 qualified and meets ISO 7637-2 test requirements for Pulse 1 (inductive switch-off), Pulse 2a/2b (battery connection/disconnection), and Pulse 3a/3b (capacitive coupled transients). These qualifications confirm its suitability for automotive powertrain, chassis, and body electronics applications.
What is the leakage current specification for SMBJ40H at its working stand-off voltage?
At its 40 V working stand-off voltage (VWM), SMBJ40H exhibits a maximum blocking leakage current (ID) of 1 µA at 25 °C. This low leakage minimizes standby power loss and avoids interference with high-impedance sensor inputs or battery-powered circuits where quiescent current is critical.
Can SMBJ40H be used in place of SMBJ40A, and what is the key difference?
No - SMBJ40H and SMBJ40A are not interchangeable without design review. SMBJ40H has a wider VBR range (44.4–54.3 V), while SMBJ40A is tighter (44.4–49.1 V). That difference affects clamping onset predictability: SMBJ40A gives more consistent turn-on behavior, whereas SMBJ40H offers higher worst-case clamping margin. Always verify system-level surge margin before substitution.
SMBJ40H Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AA, SMB
- Series:
- SMBJH
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 40V
- Voltage - Breakdown (Min):
- 44.4V
- Voltage - Clamping (Max) @ Ipp:
- 71.4V
- Current - Peak Pulse (10/1000µs):
- 8.8A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMB)
SMBJ40H FAQ
1.How can I place an order for SMBJ40H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ40H 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 SMBJ40H reliable?
The price and inventory of SMBJ40H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ40H is usually 5 days.
3.What payment methods are accepted for SMBJ40H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ40H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ40H?
SMBJ40H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ40H 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 SMBJ40H?
For technical support, including SMBJ40H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ40H requirements.
6.How does Aetrix verify that SMBJ40H is sourced from the original manufacturer or authorized distributors?
All SMBJ40H 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 SMBJ40H meets industry standards.
7.What is the process for return or replacement of SMBJ40H?
All SMBJ40H units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ40H, 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 SMBJ40H part is unused and in its original packaging.
Return procedure for SMBJ40H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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