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Taiwan Semiconductor Corporation SMBJ28C
- Part No.:
- SMBJ28C
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ28C.pdf
- Description:
- 600W, 34.6V, 10%, BIDIRECTIONAL,
- Quantity:
- Payment:
- Shipping:
Inventory:2,164
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Product details
Overview
SMBJ28C from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for high-energy surge protection in DC power lines and signal paths. It features a 28 V working stand-off voltage (VWM), 31.1–38.0 V breakdown voltage (VBR), 50.0 V maximum clamping voltage (VC) at 12.6 A peak pulse current, and 600 W peak pulse power rating with <1.0 ps response time. It is used in automotive power supply inputs and industrial I/O interfaces to protect downstream ICs from ISO 7637-2 Pulse 1/2a/2b/3a/3b transients.
For engineers reviewing the SMBJ28C datasheet, SMBJ28C pinout, SMBJ28C application, or SMBJ28C equivalent, key selection criteria include clamping voltage margin relative to protected IC's absolute maximum rating, leakage current at operating voltage, thermal derating above 25°C ambient, and DO-214AA (SMB) package compatibility with board-level ESD/surge layout practices.
Technical Context
The SMBJ28C operates as a unidirectional avalanche diode, conducting only when reverse voltage exceeds its breakdown threshold (VBR = 31.1–38.0 V @ 1 mA). Its glass-passivated junction ensures stable leakage (<1 µA at 28 V) and long-term reliability under repeated transient stress.
It meets ISO 7637-2 immunity requirements for automotive electronics, delivering 600 W peak pulse power handling with 10/1000 µs waveform, and exhibits low thermal resistance (RθJA = 55 °C/W) enabling operation up to +150 °C junction temperature in compact PCB layouts.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 28 V - Maximum continuous DC or RMS voltage the device blocks without conduction. |
| VBR min/max | 31.1 V / 38.0 V @ 1 mA - Confirmed avalanche onset range; ensures reliable triggering before protected circuit exceeds safe limits. |
| VC @ IPP | 50.0 V @ 12.6 A - Clamped voltage during 10/1000 µs surge; defines worst-case overvoltage seen by downstream IC. |
| PPK | 600 W - Peak transient energy absorption capability; supports robust protection against automotive load dump and inductive switching events. |
| ID @ VWM | <1 µA - Low leakage preserves system efficiency and prevents false triggering in high-impedance sensing circuits. |
| Package | DO-214AA (SMB) - Standard surface-mount outline with cathode band marking; compatible with automated placement and reflow soldering per J-STD-020 Level 1. |
Pinout & Package
DO-214AA (SMB) package: molded plastic case with matte tin-plated leads, polarity indicated by cathode band. Weight ≈ 0.090 g. Meets UL 94V-0 flammability and JESD 201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current path terminal | Connected to lower-potential side (e.g., GND or return path); conducts during forward surge (e.g., reverse battery protection). |
| Cathode | Avalanche conduction terminal | Connected to protected line (e.g., 24 V rail); initiates clamping when reverse voltage exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable VBR tolerance and low leakage drift over temperature and lifetime. |
| Fast response time | <1.0 ps - Limits voltage overshoot before clamping engages, critical for protecting fast-switching logic and analog front-ends. |
| ISO 7637-2 compliance | Validated for Pulse 1 (inductive load disconnect), Pulse 2a/2b (battery interruption), and Pulse 3a/3b (switching noise) - enables drop-in use in automotive ECUs. |
| Moisture sensitivity level | Level 1 per J-STD-020 - No dry-pack or bake-out required prior to assembly; simplifies manufacturing flow. |
Applications
| Automotive Power Input Protection | Industrial PLC Digital I/O Protection |
|---|---|
Use Scenario: 24 V battery-fed ECU power input subjected to load dump and jump-start surges per ISO 7637-2. IC Role / Device Role / Timing Role: Unidirectional TVS placed between power rail and ground to clamp transients before they reach DC-DC converter input. Use Value: Limits voltage to ≤50.0 V during 12.6 A surge, preventing damage to 36 V-rated input stages of buck controllers. | Use Scenario: 24 V digital input channel on programmable logic controller exposed to field-wiring induced transients. IC Role / Device Role / Timing Role: Standoff protection element across input terminals, shunting surge energy away from optocoupler or Schmitt trigger input. Use Value: Sub-µA leakage at 24 V avoids false triggering; 600 W rating handles repetitive 10/1000 µs surges common in factory floor environments. |
| LED Driver Supply Rail Protection | RS-485 Transceiver Bus Line Protection |
Use Scenario: Constant-current LED driver powered from 28 V nominal supply in outdoor signage, subject to lightning-induced surges. IC Role / Device Role / Timing Role: Primary overvoltage clamp on main DC input, upstream of MOSFET switch and current-sense amplifier. Use Value: 28 V VWM provides 10% margin above nominal rail; 50.0 V VC stays below 55 V absolute max rating of typical LED driver ICs. | Use Scenario: RS-485 transceiver bus lines (A/B) connected to long cables in building automation systems. IC Role / Device Role / Timing Role: Bidirectional protection (using SMBJ28CA variant) on differential pair; SMBJ28C used for single-ended VCC/GND rail protection. Use Value: 12.6 A IPP capacity exceeds IEC 61000-4-5 Level 4 (4 A) requirement; DO-214AA footprint allows tight layout near connector. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ28A | Narrower VBR range (31.1–34.4 V vs. 31.1–38.0 V); tighter 5% tolerance. | Better suited for precision-clamp designs where upper VBR limit must stay below 35 V. | Select SMBJ28A when VBR consistency is prioritized over worst-case clamping margin. |
| SAC28 | Same VWM (28 V), but lower PPK (400 W) and higher VC (53.3 V @ 7.5 A). | Lower surge rating makes it suitable only for lighter-duty consumer-grade interfaces. | Choose SMBJ28C over SAC28 when full 600 W ISO 7637-2 compliance is required. |
Compared with SMBJ28A and SAC28, the SMBJ28C offers broader VBR tolerance and higher surge capacity-making it preferred for automotive and industrial applications demanding margin against worst-case transients and process variation.
Availability
SMBJ28C is available at Aetrix Electronics and suitable for automotive ECU design, industrial PLC I/O modules, LED driver power rails, and RS-485 communication interface protection requiring stable component supply and full ISO 7637-2 compliance.
Supply support for SMBJ28C 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 for industrial and automotive markets.
The SMBJ series was developed specifically for high-reliability transient suppression in harsh environments, emphasizing low clamping voltage, fast response, and AEC-Q200 readiness for automotive electronics.
FAQ
What is the maximum clamping voltage of SMBJ28C under standard test conditions?
The SMBJ28C has a maximum clamping voltage (VC) of 50.0 V when subjected to a 10/1000 µs surge waveform at 12.6 A peak pulse current (IPP). This value is measured at TA = 25°C and defines the upper voltage limit imposed on protected circuitry during transient events. The SMBJ28C maintains this clamping performance across its specified operating temperature range, making it suitable for use in environments where voltage margin is critical.
Is SMBJ28C unidirectional or bidirectional, and how is polarity marked?
SMBJ28C is a unidirectional TVS diode, intended for DC line protection where polarity is fixed. Polarity is marked by a cathode band on the DO-214AA (SMB) package body; the banded end connects to the protected line (e.g., 24 V rail), while the anode connects to ground or return. For bidirectional applications, the SMBJ28CA variant is specified-SMBJ28C itself does not conduct symmetrically in both directions.
Does SMBJ28C meet automotive transient immunity standards?
Yes, SMBJ28C meets ISO 7637-2 requirements for Pulses 1, 2a, 2b, 3a, and 3b-covering load dump, battery disconnection, and switching noise events common in 12 V and 24 V automotive systems. Its 600 W peak pulse power rating, low clamping voltage, and glass-passivated junction were validated per these test profiles. However, system-level compliance also depends on PCB layout, grounding, and proximity to protected ICs.
What is the leakage current specification for SMBJ28C at its working voltage?
At its rated working stand-off voltage (VWM) of 28 V and TA = 25°C, the SMBJ28C exhibits a maximum blocking leakage current (ID) of 1 µA. This low leakage ensures minimal power loss and avoids interference in high-impedance monitoring circuits. Leakage remains well below 1 µA across the full operating temperature range (−55°C to +150°C), supporting reliable operation in extended-temperature applications.
Can SMBJ28C be used in place of SMBJ28A, and what is the key trade-off?
SMBJ28C can be used in place of SMBJ28A in most applications, but with a trade-off in VBR tolerance: SMBJ28C has a wider breakdown range (31.1–38.0 V) versus SMBJ28A's tighter 31.1–34.4 V. This means SMBJ28C may trigger later under marginal overvoltage, offering greater margin against false clamping-but slightly reduced precision in clamping onset. Designers should verify that the upper VBR limit remains safely below the protected IC's absolute maximum rating when selecting SMBJ28C.
SMBJ28C Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AA, SMB
- Series:
- SMBJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 28V
- Voltage - Breakdown (Min):
- 31.1V
- Voltage - Clamping (Max) @ Ipp:
- 50V
- Current - Peak Pulse (10/1000µs):
- 12.6A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMB)
SMBJ28C FAQ
1.How can I place an order for SMBJ28C through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ28C 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 SMBJ28C reliable?
The price and inventory of SMBJ28C are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ28C is usually 5 days.
3.What payment methods are accepted for SMBJ28C?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ28C transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ28C?
SMBJ28C orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ28C 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 SMBJ28C?
For technical support, including SMBJ28C datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ28C requirements.
6.How does Aetrix verify that SMBJ28C is sourced from the original manufacturer or authorized distributors?
All SMBJ28C 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 SMBJ28C meets industry standards.
7.What is the process for return or replacement of SMBJ28C?
All SMBJ28C units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ28C, 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 SMBJ28C part is unused and in its original packaging.
Return procedure for SMBJ28C:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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