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Taiwan Semiconductor Corporation SMAJ48C
- Part No.:
- SMAJ48C
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ48C.pdf
- Description:
- 400W, 59.3V, 10%, BIDIRECTIONAL,
- Quantity:
- Payment:
- Shipping:
Inventory:4,640
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Product details
Overview
SMAJ48C from Taiwan Semiconductor is a unidirectional 400W transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, with 48V working stand-off voltage (VWM), 53.3–65.1V breakdown voltage (VBR), and 85.5V maximum clamping voltage (VC) at 4.7A peak impulse current - designed for surge protection in DC/DC converters and industrial power supplies.
For engineers reviewing the SMAJ48C datasheet, SMAJ48C pinout, SMAJ48C application, or SMAJ48C equivalent, key selection criteria include clamping performance under 10/1000μs surge, unidirectional polarity marking, compliance with ISO 7637-2 Pulse 1/2a/2b/3a/3b, and moisture sensitivity level 1 handling per J-STD-020.
Technical Context
The SMAJ48C operates as a unidirectional avalanche diode, triggered when reverse voltage exceeds its VBR range (53.3–65.1V @ 1mA), clamping transients to ≤85.5V at 4.7A. Its glass-passivated junction ensures stable breakdown and low leakage (<1μA @ 48V).
It delivers 400W peak pulse power (10/1000μs waveform) up to 78V; above that, derated to 300W. Junction temperature range is –55°C to +150°C, supporting operation in harsh industrial environments with no thermal runaway risk under specified surge conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 48 V - Maximum continuous reverse operating voltage before conduction begins |
| VBR @ IT=1mA | 53.3–65.1 V - Breakdown voltage range defining turn-on threshold under standardized test current |
| VC @ IPPM=4.7A | 85.5 V - Clamped voltage during 10/1000μs surge, limiting downstream circuit stress |
| PPPM | 400 W - Peak pulse power handling capability, enabling robust protection against automotive/load-dump transients |
| IR @ VWM | <1 μA - Ultra-low reverse leakage preserves efficiency in high-impedance bias networks |
| Package | DO-214AC (SMA) - Surface-mount outline with cathode band marking, compatible with automated placement |
| Standards | ISO 7637-2 Pulse 1/2a/2b/3a/3b - Validated for automotive electrical system transient immunity |
Pinout & Package
DO-214AC (SMA) package: molded plastic case with matte tin-plated leads, polarity indicated by cathode band; weight ≈ 0.060g; UL 94V-0 rated compound; JESD 201 Class 2 whisker resistant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential side (e.g., ground or return path) in unidirectional configuration |
| Cathode (banded end) | Reverse-biased surge clamping terminal | Connected to protected line (e.g., 48V rail); conducts only during overvoltage events |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable, repeatable VBR and long-term reliability under repeated surge stress |
| Fast response time <1.0 ps | Clamps ESD and fast transients before sensitive ICs experience overstress |
| Moisture sensitivity level 1 | Eliminates bake requirements prior to reflow, reducing manufacturing cost and process complexity |
| Halogen-free & RoHS compliant | Meets environmental compliance mandates for industrial and automotive end equipment |
| 400W peak pulse rating (10/1000μs) | Supports high-energy surge suppression without derating in typical 48V system applications |
Applications
| Industrial Power Supply Protection | Automotive Body Control Module |
|---|---|
Use Scenario: Protecting 48V input rails in DIN-rail mounted PLC power modules against load dump and inductive switching spikes. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed across input terminals to clamp surges before they reach DC/DC controller ICs. Use Value: Limits transient voltage to ≤85.5V, preventing damage to 100V-rated MOSFETs and gate drivers on the primary side. | Use Scenario: Safeguarding LIN bus interface circuits and microcontroller I/O pins in door module ECUs exposed to battery transients. IC Role / Device Role / Timing Role: Standoff protection device connected between LIN line and chassis ground, activated only during ISO 7637-2 Pulse 2b events. Use Value: Maintains signal integrity by suppressing >100V spikes to sub-90V levels within nanoseconds, avoiding false resets or latch-up. |
| Telecom DC/DC Converter Input | LED Driver Surge Suppression |
Use Scenario: Input-side transient protection for isolated 48V-to-12V flyback converters powering base station RF modules. IC Role / Device Role / Timing Role: Primary-side clamping element absorbing energy from lightning-induced surges coupled via AC mains or PoE injectors. Use Value: Withstands 400W pulses without degradation, ensuring converter uptime in outdoor telecom cabinets per IEC 61000-4-5 Level 3. | Use Scenario: Overvoltage protection for constant-current LED drivers used in street lighting with long cable runs susceptible to induced surges. IC Role / Device Role / Timing Role: Parallel-connected TVS on driver output to clamp inductive kickback from relay-controlled loads or grid switching noise. Use Value: Clamps 10/1000μs transients to 85.5V, protecting 100V-rated LED string controllers and maintaining lumen consistency during storms. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ48A | VBR = 53.3–58.9V (tighter max), VC = 77.4V @ 5.2A - lower clamping but reduced peak current rating | Better for low-clamp-critical 48V logic rails; less suitable for high-energy load dump where 4.7A IPPM margin matters | Select SMAJ48A if clamping voltage budget is <78V and surge repetition is infrequent |
| ON Semiconductor SMAJ48CA | Bidirectional variant (suffix CA); symmetric VBR/VC in both polarities; same package and PPPM | Required for AC-coupled or floating-bus applications (e.g., RS-485, CAN FD lines); not interchangeable in unidirectional 48V rail use | Choose SMAJ48CA only when bidirectional protection is explicitly required - SMAJ48C is not pin-compatible |
Compared with SMAJ48A and SMAJ48CA, the SMAJ48C offers optimal balance of clamping voltage (85.5V), peak current capacity (4.7A), and unidirectional simplicity for fixed-polarity 48V DC systems - making it preferred for industrial power inputs where polarity is known and surge energy is high.
Availability
SMAJ48C is available at Aetrix Electronics and suitable for industrial power supply protection, automotive body control modules, telecom DC/DC converter input stages, and LED driver surge suppression requiring stable component supply and full traceability.
Supply support for SMAJ48C 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, and protection devices since 1979.
The SMAJ series was developed specifically for high-reliability transient suppression in automotive and industrial 12V–188V systems, emphasizing robustness under ISO 7637-2 and JEDEC-compliant packaging.
FAQ
What is the polarity configuration of the SMAJ48C?
The SMAJ48C is a unidirectional TVS diode, with cathode indicated by a band on the DO-214AC (SMA) package. It conducts only when the cathode is at higher potential than the anode - ideal for protecting positive 48V rails referenced to ground. Unlike bidirectional variants (e.g., SMAJ48CA), it does not suppress surges on both polarities, so correct orientation during PCB layout is essential for the SMAJ48C to function as intended.
Does the SMAJ48C meet automotive transient standards?
Yes, the SMAJ48C meets ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b requirements for automotive electrical system immunity. Its 400W peak pulse power rating (10/1000μs), fast response time (<1.0 ps), and clamping voltage of 85.5V at 4.7A enable reliable protection against load dump, jump start, and inductive switching events - all validated per TSC's characterization data for the SMAJ48C.
What is the maximum junction temperature for the SMAJ48C?
The SMAJ48C has a maximum junction temperature (TJMAX) of +150°C and an operating junction temperature range of –55°C to +150°C. This wide range supports deployment in under-hood automotive modules, industrial enclosures, and outdoor telecom equipment. Thermal derating follows Fig.2 in the official SMAJ48C datasheet, with power dissipation decreasing linearly above +25°C ambient.
How does the SMAJ48C differ from the SMAJ48A?
The SMAJ48C and SMAJ48A share the same VWM (48V) and package (DO-214AC), but differ in VBR range (53.3–65.1V vs. 53.3–58.9V) and clamping performance: SMAJ48C clamps at 85.5V @ 4.7A, while SMAJ48A clamps at 77.4V @ 5.2A. The SMAJ48C provides higher surge current margin; the SMAJ48A offers tighter clamping - both are valid choices depending on whether energy handling or voltage limiting dominates the SMAJ48C design requirement.
Is the SMAJ48C halogen-free and RoHS compliant?
Yes, the SMAJ48C is halogen-free per IEC 61249-2-21 and RoHS compliant, using molding compound and lead finish that meet EU Directive 2011/65/EU. The matte tin-plated leads are solderable per J-STD-002, and the entire assembly passes JESD 201 Class 2 whisker testing - confirming suitability for high-reliability, environmentally regulated applications including industrial automation and automotive electronics where the SMAJ48C is deployed.
SMAJ48C Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AC, SMA
- Series:
- SMAJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 48V
- Voltage - Breakdown (Min):
- 53.3V
- Voltage - Clamping (Max) @ Ipp:
- 85.5V
- Current - Peak Pulse (10/1000µs):
- 4.7A
- Power - Peak Pulse:
- 400W
- 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-214AC (SMA)
SMAJ48C FAQ
1.How can I place an order for SMAJ48C through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ48C 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 SMAJ48C reliable?
The price and inventory of SMAJ48C are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ48C is usually 5 days.
3.What payment methods are accepted for SMAJ48C?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ48C transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ48C?
SMAJ48C orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ48C 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 SMAJ48C?
For technical support, including SMAJ48C datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ48C requirements.
6.How does Aetrix verify that SMAJ48C is sourced from the original manufacturer or authorized distributors?
All SMAJ48C 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 SMAJ48C meets industry standards.
7.What is the process for return or replacement of SMAJ48C?
All SMAJ48C units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ48C, 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 SMAJ48C part is unused and in its original packaging.
Return procedure for SMAJ48C:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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