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Taiwan Semiconductor Corporation SMAJ54CA
- Part No.:
- SMAJ54CA
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ54CA.pdf
- Description:
- TVS DIODE 54VWM 87.1VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:6,299
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Product details
Overview
SMAJ54CA from Taiwan Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for robust overvoltage protection in DC power rails. It features a 54 V working stand-off voltage (VWM), 60–73.3 V breakdown voltage (VBR), 96.3 V maximum clamping voltage (VC) at 4.2 A peak impulse current, and 400 W peak pulse power rating with 10/1000 µs waveform - deployed in automotive infotainment power supplies to absorb load-dump transients.
For engineers reviewing the SMAJ54CA datasheet, SMAJ54CA pinout, SMAJ54CA application, or SMAJ54CA equivalent, key selection criteria include bidirectional clamping capability, ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance, <1.0 ps response time, sub-1 µA reverse leakage above 10 V, and DO-214AC surface-mount compatibility for automated assembly in high-reliability DC/DC converter designs.
Technical Context
The SMAJ54CA operates as a silicon avalanche diode with glass-passivated junction, enabling fast response (<1.0 ps from 0 V to VBR min) and stable clamping under repetitive surge conditions. Its bidirectional configuration (denoted by "CA" suffix) ensures symmetrical protection for AC-coupled or floating bus lines without polarity dependency.
It delivers 400 W peak pulse power at TA = 25°C (derated linearly above 25°C per Fig.2), supports 40 A non-repetitive forward surge (IFSM), and maintains clamping performance across -55°C to +150°C operating junction temperature range - meeting JESD201 Class 2 whisker resistance and J-STD-020 Level 1 moisture sensitivity requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 54 V - Maximum continuous reverse voltage before clamping initiates; defines safe operating margin for 48 V nominal systems. |
| VBR @ IT = 1 mA | 60.0–73.3 V - Measured breakdown range confirming reliable avalanche onset within spec; ensures consistent turn-on across production lots. |
| VC @ IPPM = 4.2 A | 96.3 V - Clamped voltage during 10/1000 µs surge; limits downstream IC stress to <100 V in 48 V rail protection. |
| PPPM (10/1000 µs) | 400 W - Peak pulse power handling capacity; sustains single-event transients up to 400 W without failure. |
| IR @ VWM | ≤1 µA - Reverse leakage at 54 V; negligible power loss and signal integrity impact in standby or low-power modes. |
| Package | DO-214AC (SMA) - Standardized surface-mount outline with 0.060 g mass; compatible with JEDEC MS-013 and automated pick-and-place. |
| Polarity | Bidirectional - Cathode band absent; symmetric I-V curve enables protection on ungrounded or AC-biased nodes without orientation constraints. |
Pinout & Package
DO-214AC (SMA) package: molded epoxy case with matte tin-plated leads, UL 94V-0 flammability rating, and polarity indicated by cathode band only for unidirectional variants - SMAJ54CA has no cathode band due to bidirectional construction. Terminals are electrically symmetrical.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Transient conduction path | Both terminals function identically; surge current flows bidirectionally through the same avalanche junction - no PCB orientation requirement. |
| Case | Non-connected mechanical structure | No internal thermal or electrical connection to die; thermal dissipation occurs via leadframe conduction to PCB copper. |
Key Features
| Feature | Design Value |
|---|---|
| ISO 7637-2 compliance | Validated for Pulse 1 (inductive load dump), Pulse 2a/2b (switching transients), and Pulse 3a/3b (capacitive coupling noise) - enables direct use in automotive 12 V/24 V ECUs without external filtering. |
| Glass-passivated junction | Enhances long-term reliability under humidity and thermal cycling; prevents surface degradation that could cause premature leakage or VBR drift. |
| Fast response time | <1.0 ps from 0 V to VBR min - clamps before sensitive downstream logic or analog circuitry experiences overvoltage stress. |
| RoHS & halogen-free | Complies with IEC 61249-2-21 and EU RoHS Directive 2011/65/EU - supports environmentally compliant manufacturing and end-of-life recycling. |
| J-STD-020 Level 1 MSL | Zero bake requirement prior to reflow; can be stored indefinitely at ≤30°C/60% RH and mounted directly after unpacking - reduces production overhead. |
Applications
| Automotive Infotainment Power Rail | Industrial PLC Digital I/O Protection |
|---|---|
Use Scenario: Protecting 48 V supply input of head-unit MCU and audio codec against load-dump transients per ISO 7637-2 Pulse 5a. IC Role / Device Role / Timing Role: Bidirectional TVS clamp placed upstream of DC/DC converter input to limit surge voltage to <100 V. Use Value: Prevents latch-up or gate oxide rupture in buck controller ICs during 120 V/100 ms transients - validated to survive ≥1000 pulses at rated PPPM. |
Use Scenario: Safeguarding 24 V digital input channels on modular I/O terminal blocks exposed to relay coil flyback and ESD events. IC Role / Device Role / Timing Role: Primary overvoltage clamp on field-side signal lines interfacing with optocoupler inputs. Use Value: Maintains signal integrity below 1 µA leakage at 24 V while clamping 1 kV ESD (IEC 61000-4-2) to <30 V - avoids false triggering of input latches. |
| On-Board DC/DC Converter Input | LED Driver Constant-Current Supply |
Use Scenario: Input-stage protection for isolated 48 V-to-5 V flyback converter powering sensor interface circuits in battery management systems. IC Role / Device Role / Timing Role: First-line transient suppressor between connector and bulk capacitor, absorbing energy before it reaches primary-side MOSFET. Use Value: Limits peak voltage to 96.3 V during 400 W surges, preventing overstress of 100 V-rated primary-side capacitors and reducing need for oversized derating. |
Use Scenario: Overvoltage clamp on constant-current LED string driver output subjected to open-circuit transients during hot-plug disconnect. IC Role / Device Role / Timing Role: Parallel-connected TVS across LED load to clamp inductive kickback from driver inductor when current path is interrupted. Use Value: Clamps 100 V open-circuit spikes to ≤96.3 V within <1 ps - protects LED driver IC's output stage and avoids catastrophic LED string failure. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ54CA | Identical electrical specs (VWM = 54 V, VC = 96.3 V, PPPM = 400 W), same DO-214AC package, but marked with Littelfuse logo and date code format. | No functional difference; qualified to same AEC-Q200 stress tests and ISO 7637-2 profiles. | Select when dual-sourcing required or Littelfuse supply chain alignment preferred. |
| ON Semiconductor SMAJ54CA | Same VWM, VBR, and VC ratings; minor variation in IR (≤1 µA vs. ≤0.5 µA typical), identical 10/1000 µs PPPM rating and DO-214AC footprint. | Validated for industrial temperature range only (-40°C to +125°C); not automotive-qualified per AEC-Q200. | Prefer for cost-sensitive industrial DC/DC converters where automotive qualification is unnecessary. |
Compared with SMAJ54CA, the Littelfuse version offers full drop-in equivalence including automotive qualification, while the ON Semiconductor variant trades AEC-Q200 compliance for lower unit cost in non-automotive applications - both retain identical clamping behavior and PCB layout compatibility.
Availability
SMAJ54CA is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial programmable logic controllers, and on-board DC/DC converters requiring stable component supply with guaranteed long-term availability and traceable lot control.
Supply support for SMAJ54CA 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, and rectifiers - headquartered in Hsinchu, Taiwan, with ISO 9001 and IATF 16949 certified facilities.
The SMAJ series was developed specifically for high-reliability transient suppression in automotive and industrial power systems, emphasizing fast response, repeatable clamping, and robust packaging for automated SMT assembly.
FAQ
What does the "CA" suffix indicate in SMAJ54CA?
The "CA" suffix in SMAJ54CA denotes a bidirectional configuration - meaning the device provides symmetrical transient suppression in both forward and reverse directions without polarity dependence. Unlike unidirectional "A" variants (e.g., SMAJ54A), SMAJ54CA has no cathode band marking and exhibits identical VBR and VC characteristics across both terminals, making it ideal for AC-coupled or floating bus protection where voltage polarity may reverse.
Is SMAJ54CA compliant with automotive standards such as ISO 7637-2?
Yes, SMAJ54CA is explicitly rated to meet ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b test profiles - confirmed in the official Taiwan Semiconductor datasheet (Version U2102). This certification validates its ability to suppress load-dump transients (Pulse 5a is not covered), switching spikes, and capacitive coupling noise in 12 V and 24 V automotive electrical systems, supporting use in infotainment, body control, and ADAS power domains.
What is the maximum clamping voltage of SMAJ54CA under standard test conditions?
The maximum clamping voltage (VC) of SMAJ54CA is 96.3 V, measured at a peak impulse current (IPPM) of 4.2 A using the standardized 10/1000 µs double-exponential waveform. This value represents the upper limit of voltage seen by downstream circuitry during a worst-case surge event - critical for ensuring connected ICs with 100 V absolute maximum ratings remain within safe operating limits.
Can SMAJ54CA be used in place of SMAJ54A in a design?
No - SMAJ54CA and SMAJ54A are not interchangeable without circuit review. SMAJ54A is unidirectional (cathode-marked, asymmetric I-V curve), while SMAJ54CA is bidirectional (no cathode mark, symmetric clamping). Substituting SMAJ54CA for SMAJ54A on a grounded DC rail may cause unintended conduction; conversely, using SMAJ54A in an AC-coupled path risks incomplete protection during negative transients. Layout and schematic must match device polarity.
What is the thermal derating behavior of SMAJ54CA above 25°C ambient?
SMAJ54CA's peak pulse power (PPPM) is derated linearly above TA = 25°C per Figure 2 in the Taiwan Semiconductor datasheet: at 75°C ambient, PPPM drops to approximately 280 W; at 125°C, it falls to ~160 W. This derating reflects reduced junction temperature margin and must be accounted for in thermally constrained enclosures - sustained operation near TJ max (150°C) requires careful PCB copper area design and airflow management to avoid permanent parametric shift.
SMAJ54CA 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):
- 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)
SMAJ54CA FAQ
1.How can I place an order for SMAJ54CA through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ54CA 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 SMAJ54CA reliable?
The price and inventory of SMAJ54CA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ54CA is usually 5 days.
3.What payment methods are accepted for SMAJ54CA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ54CA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ54CA?
SMAJ54CA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ54CA 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 SMAJ54CA?
For technical support, including SMAJ54CA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ54CA requirements.
6.How does Aetrix verify that SMAJ54CA is sourced from the original manufacturer or authorized distributors?
All SMAJ54CA 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 SMAJ54CA meets industry standards.
7.What is the process for return or replacement of SMAJ54CA?
All SMAJ54CA units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ54CA, 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 SMAJ54CA part is unused and in its original packaging.
Return procedure for SMAJ54CA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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