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Taiwan Semiconductor Corporation SMAJ54A
- Part No.:
- SMAJ54A
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ54A.pdf
- Description:
- TVS DIODE 54VWM 87.1VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:7,538
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Product details
Overview
SMAJ54A from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for clamping fast-rising ESD and surge transients in DC power lines. It features a 54 V working stand-off voltage (VWM), 60.0–66.3 V breakdown voltage (VBR) at 1 mA test current, 87.1 V maximum clamping voltage (VC) at 4.6 A peak impulse current, and 400 W peak pulse power rating with 10/1000 µs waveform.
For engineers reviewing the SMAJ54A datasheet, SMAJ54A pinout, SMAJ54A application, or SMAJ54A equivalent, this device is selected for robust overvoltage protection in DC/DC converters, industrial power adapters, automotive body electronics, and lighting control modules where low clamping voltage and sub-nanosecond response are critical.
Technical Context
The SMAJ54A operates as a unidirectional avalanche diode, triggering when reverse voltage exceeds its specified VBR range and clamping transient energy into its silicon junction. Its glass-passivated chip junction ensures stable leakage performance and long-term reliability under repeated surge stress.
It meets ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b for automotive load-dump and inductive-switching immunity, with a maximum reverse leakage current of 1 µA at 54 V and an operating junction temperature range from –55 °C to +150 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 54 V - Maximum continuous reverse operating voltage before conduction begins; defines safe DC bias margin. |
| VBR @ IT = 1 mA | 60.0–66.3 V - Breakdown threshold range; ensures consistent turn-on across production lots. |
| VC @ IPPM = 4.6 A | 87.1 V - Clamped voltage during 10/1000 µs surge; determines protected circuit's maximum transient exposure. |
| PPPM (10/1000 µs) | 400 W - Peak surge power handling; supports high-energy transients without failure. |
| IR @ VWM | ≤1 µA - Reverse leakage at rated stand-off; minimizes standby power loss in battery-powered systems. |
| Package | DO-214AC (SMA) - Industry-standard surface-mount outline; compatible with automated pick-and-place and reflow. |
| Polarity | Cathode band marked - Unambiguous orientation for PCB layout and assembly verification. |
Pinout & Package
DO-214AC (SMA) package: molded plastic case with matte tin-plated leads, UL 94V-0 rated, 0.060 g typical weight, polarity indicated by cathode band.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unmarked end) | Forward conduction terminal | Connected to lower-potential side (e.g., GND or return path) in unidirectional clamp configuration. |
| Cathode (banded end) | Reverse-biased clamping terminal | Connected to protected line (e.g., +54 V rail); conducts only during overvoltage events. |
Key Features
| Feature | Design Value |
|---|---|
| Fast response time | Typically <1.0 ps from 0 V to VBR min - Enables suppression of nanosecond-scale ESD pulses before IC damage occurs. |
| Glass passivated junction | Stable VBR tolerance and low IR drift over temperature and lifetime - Ensures consistent protection behavior in harsh environments. |
| ISO 7637-2 compliance | Validated for Pulse 1/2a/2b/3a/3b - Meets automotive OEM requirements for battery-line surge immunity without external filtering. |
| Moisture sensitivity level | MSL Level 1 per J-STD-020 - No floor-life limitation or bake requirement prior to reflow soldering. |
| RoHS & halogen-free | Compliant with IEC 61249-2-21 - Supports environmentally regulated industrial and automotive manufacturing. |
Applications
| Automotive Body Control Module | Industrial DC/DC Converter Input |
|---|---|
Use Scenario: Protects microcontroller I/O and CAN transceiver power rails against load dump and alternator ripple in vehicle door modules. IC Role / Device Role / Timing Role: Unidirectional TVS clamping element placed between 12 V supply and ground, triggered within picoseconds of overvoltage onset. Use Value: Limits transient voltage to ≤87.1 V, preventing latch-up or gate oxide rupture in 3.3 V/5 V logic interfaces downstream. |
Use Scenario: Shields primary-side controller ICs and MOSFET gates from switching-induced spikes in isolated 48 V-to-12 V buck converters. IC Role / Device Role / Timing Role: Standoff-clamp protector on input bus, absorbing repetitive 400 W surges without degradation over >10⁵ cycles. Use Value: Maintains ≤1 µA leakage at 54 V, avoiding unnecessary quiescent current draw in always-on power management subsystems. |
| LED Driver Power Supply | Medical Equipment AC-DC Adapter |
Use Scenario: Safeguards constant-current LED driver ICs from mains-coupled surges and inductive kickback in streetlight ballasts. IC Role / Device Role / Timing Role: Primary-line TVS on bulk capacitor input, activated before MOVs reach thermal limit during multi-pulse events. Use Value: Delivers 400 W peak power handling with 10/1000 µs waveform - sustains protection during sustained lightning-induced surges. |
Use Scenario: Provides secondary-side overvoltage clamping on isolated 24 V output rails of Class II medical AC-DC adapters. IC Role / Device Role / Timing Role: Final-stage transient barrier before patient-connected circuits, meeting IEC 60601-1 creepage/clearance and leakage constraints. Use Value: Achieves MSL Level 1 and RoHS/halogen-free compliance - satisfies regulatory documentation for safety-critical power supplies. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ54 | Higher clamping voltage: VC = 96.3 V @ 4.2 A vs. 87.1 V @ 4.6 A; wider VBR range (60.0–73.3 V). | Less effective clamping margin for sensitive 54 V-rated ICs; suitable where higher VC is acceptable. | Select SMAJ54A when tighter clamping and lower leakage are required; choose SMAJ54 for cost-sensitive designs with relaxed VC budget. |
| SMBJ54A | Same electrical specs but SMB (DO-214AA) package: 2.54 mm lead pitch vs. SMA's 2.29 mm; 600 W peak power rating. | Requires larger PCB footprint and different stencil design; better thermal dissipation for high-duty-cycle surges. | Choose SMBJ54A for higher-power or thermally constrained layouts; retain SMAJ54A for space-constrained, high-density boards. |
Compared with SMAJ54 and SMBJ54A, the SMAJ54A delivers the lowest clamping voltage in the SMA footprint while maintaining full ISO 7637-2 compliance - making it optimal for protecting modern 54 V automotive and industrial power rails where voltage margin is critical.
Availability
SMAJ54A is available at Aetrix Electronics and suitable for automotive body electronics, industrial DC/DC converter inputs, and LED driver power supplies requiring stable component supply, long-lifecycle availability, and traceable sourcing.
Supply support for SMAJ54A 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 SMAJ series was developed specifically for high-reliability, surface-mount transient suppression in automotive and industrial power systems - emphasizing low clamping, fast response, and AEC-Q200-aligned robustness.
FAQ
What is the clamping voltage of SMAJ54A under standard 10/1000 µs surge conditions?
The SMAJ54A has a maximum clamping voltage (VC) of 87.1 V when subjected to a 4.6 A peak impulse current with a 10/1000 µs waveform. This value is measured per JEDEC standards and guarantees that downstream circuitry sees no more than 87.1 V during defined surge events - critical for safeguarding 54 V-rated components. The SMAJ54A achieves this while maintaining tight VBR tolerance and low leakage.
Is SMAJ54A unidirectional or bidirectional, and how is polarity identified?
SMAJ54A is a unidirectional TVS diode, intended for DC line protection where polarity is fixed. Polarity is identified by a cathode band marked on the DO-214AC (SMA) package - the banded end connects to the protected line (e.g., +54 V), and the unmarked end connects to ground. Bidirectional variants use "CA" suffixes (e.g., SMAJ54CA), which are electrically distinct and not interchangeable with SMAJ54A.
Does SMAJ54A meet automotive surge immunity standards?
Yes, SMAJ54A meets ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b requirements for automotive electrical systems. It is validated for load-dump, supply interruption, and inductive switching transients on 12 V and 24 V networks. Its 400 W peak pulse power rating, sub-nanosecond response, and MSL Level 1 packaging make it suitable for under-hood and body-control module applications without additional filtering.
What is the maximum steady-state power dissipation for SMAJ54A?
The SMAJ54A has a steady-state power dissipation (PD) rating of 1 W at TA = 25 °C. This reflects its ability to handle continuous reverse-bias leakage and minor overvoltage conditions without thermal runaway. Derating applies above 25 °C per the pulse derating curve in the datasheet; for transient suppression, the 400 W peak pulse rating (10/1000 µs) governs surge capability, not PD.
How does SMAJ54A differ from SMAJ54 in terms of electrical performance?
SMAJ54A offers tighter breakdown voltage tolerance (60.0–66.3 V vs. 60.0–73.3 V for SMAJ54) and lower clamping voltage (87.1 V vs. 96.3 V at rated IPPM), resulting in superior protection margin for 54 V systems. It also exhibits slightly higher peak impulse current (4.6 A vs. 4.2 A) and identical 1 µA leakage at VWM. These differences make SMAJ54A preferable where precise clamping and minimal voltage overshoot are required.
SMAJ54A 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:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 54V
- Voltage - Breakdown (Min):
- 60V
- Voltage - Clamping (Max) @ Ipp:
- 87.1V
- Current - Peak Pulse (10/1000µs):
- 4.6A
- 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)
SMAJ54A FAQ
1.How can I place an order for SMAJ54A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ54A 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 SMAJ54A reliable?
The price and inventory of SMAJ54A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ54A is usually 5 days.
3.What payment methods are accepted for SMAJ54A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ54A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ54A?
SMAJ54A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ54A 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 SMAJ54A?
For technical support, including SMAJ54A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ54A requirements.
6.How does Aetrix verify that SMAJ54A is sourced from the original manufacturer or authorized distributors?
All SMAJ54A 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 SMAJ54A meets industry standards.
7.What is the process for return or replacement of SMAJ54A?
All SMAJ54A units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ54A, 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 SMAJ54A part is unused and in its original packaging.
Return procedure for SMAJ54A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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