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Taiwan Semiconductor Corporation SMCJ28A
- Part No.:
- SMCJ28A
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ28A.pdf
- Description:
- TVS DIODE 28VWM 45.4VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:7,269
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Product details
Overview
SMCJ28A from Taiwan Semiconductor is a unidirectional 1500W surface-mount transient voltage suppressor (TVS) diode in DO-214AB (SMC) package, with 28V working stand-off voltage (VWM), 31.1–34.4V breakdown voltage (VBR), and 45.4V maximum clamping voltage (VC) at 34A peak pulse current-designed for automotive load-dump and inductive switching protection.
For engineers reviewing the SMCJ28A datasheet, SMCJ28A pinout, SMCJ28A application, or SMCJ28A equivalent, key selection criteria include clamping performance under ISO 7637-2 Pulse 1/2a/2b/3a/3b, junction temperature derating above 25°C, moisture sensitivity level (MSL 1), and unidirectional polarity marking per cathode band.
Technical Context
The SMCJ28A employs a glass-passivated silicon junction optimized for fast transient response (<1.0 ps rise time from 0 V to VBR min) and low leakage (<1 µA at 28 V). Its thermal design supports 150°C max junction temperature with RθJA = 55°C/W and RθJC = 10°C/W, enabling robust operation in high-ambient automotive and industrial environments.
It meets ISO 7637-2 immunity requirements for automotive electronics-including Pulse 1 (inductive load dump), Pulse 2a/2b (switching transients), and Pulse 3a/3b (capacitive coupling)-and complies with RoHS and halogen-free standards per IEC 61249-2-21.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 28 V - Maximum continuous reverse operating voltage before clamping begins |
| VBR min/max | 31.1 V / 34.4 V @ IT = 1 mA - Confirmed breakdown range ensuring reliable turn-on during transients |
| VC @ IPPM | 45.4 V @ 34 A - Clamping voltage limits downstream IC stress during 10/1000 µs surge events |
| PPK | 1500 W - Peak pulse power handling capability per single 1 ms non-repetitive surge |
| IR @ VWM | <1 µA - Minimal leakage preserves system standby power integrity |
| TJ max | +150 °C - Enables use in under-hood automotive locations without thermal derating penalties |
| Package | DO-214AB (SMC) - Standardized surface-mount footprint compatible with automated placement and J-STD-002 soldering |
Pinout & Package
DO-214AB (SMC) package: molded plastic case with matte tin-plated leads, polarity indicated by cathode band; weight ≈ 0.210 g; UL 94V-0 rated molding compound; MSL Level 1 per J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (banded end) | Reverse-biased anode connection point | Connected to protected line (e.g., 28V rail); clamps positive transients to ground when voltage exceeds VBR |
| Anode | Reference/ground return path | Typically tied to system ground plane; completes clamping path for unidirectional surge suppression |
Key Features
| Feature | Design Value |
|---|---|
| ISO 7637-2 compliance | Validated for Pulse 1, 2a, 2b, 3a, and 3b waveforms-enables direct integration into automotive ECU power rails |
| Fast response time | <1.0 ps from 0 V to VBR min-prevents overshoot damage to sensitive CAN/LIN transceivers and microcontrollers |
| Glass passivated junction | Enhances long-term reliability and stability of VBR under thermal cycling and humidity exposure |
| Low IR at VWM | <1 µA leakage at 28 V-minimizes quiescent current draw in always-on vehicle modules (e.g., body control units) |
Applications
| Automotive Power Rail Protection | Industrial PLC Input Protection |
|---|---|
Use Scenario: Suppressing load-dump transients on 24V battery-fed ECUs in passenger vehicles and commercial trucks. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery rail and DC-DC converter input to clamp spikes up to ±120 V. Use Value: Limits clamped voltage to 45.4 V, protecting downstream 40V-rated regulators and MCU power supplies per ISO 7637-2 Pulse 5a. | Use Scenario: Shielding digital input channels of programmable logic controllers from inductive kickback in solenoid valve control circuits. IC Role / Device Role / Timing Role: Mounted across input terminals to shunt 200 A surge currents from relay coil de-energization. Use Value: Withstands 34 A peak impulse at 45.4 V clamping, preventing false triggering and latch-up in optocoupler-isolated inputs. |
| LED Driver Overvoltage Protection | ESD-Sensitive Sensor Interface |
Use Scenario: Safeguarding constant-current LED drivers in streetlight systems exposed to lightning-induced surges on AC mains lines. IC Role / Device Role / Timing Role: Connected in parallel with driver output to clamp transients before they reach high-brightness LED strings. Use Value: 1500 W peak power rating absorbs multi-millisecond surges while maintaining <1 µA leakage to avoid dimming drift. | Use Scenario: Protecting analog front-ends of automotive cabin temperature/humidity sensors connected to LIN bus. IC Role / Device Role / Timing Role: Placed at sensor PCB edge to divert ESD events (IEC 61000-4-2 ±8 kV contact) before reaching signal conditioning op-amps. Use Value: Sub-1 ps response ensures clamping initiates before ESD pulse reaches sensitive CMOS inputs, reducing failure rate in field deployments. |
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 (ON Semiconductor) | Same DO-214AA package; lower PPK = 600 W; VC = 48.4 V @ 12.3 A | Lower surge capacity suits consumer-grade 24V systems but not automotive load-dump duty cycles | Select SMCJ28A when 1500 W peak power and ISO 7637-2 compliance are mandatory |
| P6SMB28A (STMicroelectronics) | DO-214AA package; PPK = 600 W; VC = 45.7 V @ 13.1 A; meets IEC 61000-4-5 Level 4 | Rated for lower energy surges; lacks explicit ISO 7637-2 validation per datasheet | Choose SMCJ28A for automotive-grade immunity where Pulse 1/2a/2b/3a/3b testing is required |
Compared with SMBJ28A and P6SMB28A, the SMCJ28A delivers 2.5× higher peak power handling and documented ISO 7637-2 qualification-making it the only option among the three validated for full automotive power rail transient immunity without external series impedance.
Availability
SMCJ28A is available at Aetrix Electronics and suitable for automotive electronic control units, industrial programmable logic controllers, LED lighting drivers, and ESD-sensitive sensor interfaces requiring stable component supply across extended production lifecycles.
Supply support for SMCJ28A 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 analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in TVS diodes, rectifiers, MOSFETs, and power management devices.
The SMCJ series was developed specifically for high-energy transient suppression in harsh automotive and industrial environments-emphasizing ISO 7637-2 compliance, MSL 1 reliability, and consistent clamping performance across temperature.
FAQ
What is the clamping voltage of the SMCJ28A and how is it measured?
The SMCJ28A has a maximum clamping voltage (VC) of 45.4 V, measured at a peak pulse current (IPPM) of 34 A using the standardized 10/1000 µs double-exponential waveform per Fig.5 in the datasheet. This value represents the upper limit of voltage seen by downstream circuitry during worst-case transient events, ensuring compatibility with 40V-rated components in 24V systems.
Is the SMCJ28A suitable for bidirectional transient protection?
No, the SMCJ28A is a unidirectional TVS diode intended for DC applications with defined polarity. For bidirectional protection, Taiwan Semiconductor offers the SMCJ28CA variant (with CA suffix), which provides symmetrical clamping in both directions and uses different marking (e.g., GFG for unidirectional vs. GFG-C for bidirectional).
Does the SMCJ28A meet automotive qualification standards beyond ISO 7637-2?
The SMCJ28A is explicitly tested and compliant with ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b, but it is not AEC-Q200 qualified. It is designed for automotive *application-level* immunity-not component-level qualification-so system-level validation per OEM requirements remains necessary.
What is the thermal resistance profile of the SMCJ28A and how does it affect PCB layout?
The SMCJ28A has RθJA = 55°C/W and RθJC = 10°C/W. To maintain TJ ≤ 150°C at full 1500 W surge, PCB copper area must be sufficient to dissipate heat-typically ≥ 100 mm² of 2 oz copper connected to both terminals. Thermal vias under the pad improve conduction but do not eliminate ambient derating above 25°C.
How does the SMCJ28A compare to the SMCJ28 (non-A) version?
The SMCJ28A has tighter VBR tolerance (31.1–34.4 V) versus SMCJ28 (31.1–38.0 V), resulting in more predictable clamping onset and lower VC (45.4 V vs. 50.0 V at same IPPM). The "A" suffix indicates improved parameter consistency for critical automotive and industrial designs where clamping precision matters.
SMCJ28A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AB, SMC
- Series:
- SMCJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 28V
- Voltage - Breakdown (Min):
- 31.1V
- Voltage - Clamping (Max) @ Ipp:
- 45.4V
- Current - Peak Pulse (10/1000µs):
- 33A
- Power - Peak Pulse:
- 1500W (1.5kW)
- Power Line Protection:
- Yes
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AB (SMCJ)
SMCJ28A FAQ
1.How can I place an order for SMCJ28A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ28A 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 SMCJ28A reliable?
The price and inventory of SMCJ28A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ28A is usually 5 days.
3.What payment methods are accepted for SMCJ28A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ28A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ28A?
SMCJ28A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ28A 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 SMCJ28A?
For technical support, including SMCJ28A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ28A requirements.
6.How does Aetrix verify that SMCJ28A is sourced from the original manufacturer or authorized distributors?
All SMCJ28A 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 SMCJ28A meets industry standards.
7.What is the process for return or replacement of SMCJ28A?
All SMCJ28A units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ28A, 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 SMCJ28A part is unused and in its original packaging.
Return procedure for SMCJ28A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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