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Taiwan Semiconductor Corporation SMAJ54H
- Part No.:
- SMAJ54H
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ54H.pdf
- Description:
- TVS DIODE 54VWM 96.3VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:5,956
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Product details
Overview
SMAJ54H from Taiwan Semiconductor is a unidirectional surface-mount 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), 60.0–73.3 V breakdown voltage (VBR), 96.3 V clamping voltage (VC) at 4.2 A peak impulse current, and 400 W peak pulse power rating with 10/1000 µs waveform - ideal for protecting automotive-grade DC/DC converters against ISO 7637-2 Pulse 1/2a/2b/3a/3b transients.
For engineers reviewing the SMAJ54H datasheet, SMAJ54H pinout, SMAJ54H application, or SMAJ54H equivalent, key selection criteria include its AEC-Q101 qualification, <1.0 ps response time, <1 µA reverse leakage at VWM, glass-passivated junction, and UL 94V-0 molded case - all critical for reliable operation in harsh automotive and industrial environments.
Technical Context
The SMAJ54H operates as a unidirectional avalanche diode, clamping transient overvoltages above its breakdown threshold while maintaining low leakage (<1 µA) below 54 V. Its fast response (<1.0 ps) and low clamping ratio (VC/VBR ≈ 1.32) ensure minimal overshoot during ESD or load-dump events.
Designed for single-die, uni-polar protection, it supports peak impulse currents up to 4.2 A (10/1000 µs), with thermal derating above 25°C per Fig.2 and junction temperature limits of –55°C to +150°C. It meets ISO 7637-2 Pulse 1 (inductive switch-off), Pulse 2a/2b (battery disconnect/load dump), and Pulse 3a/3b (capacitive coupling) immunity requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 54 V - maximum continuous reverse operating voltage before conduction begins; defines safe DC rail margin. |
| VBR min/max | 60.0 / 73.3 V at 1 mA - guaranteed avalanche onset range; ensures consistent turn-on across production lots. |
| VC @ IPPM | 96.3 V at 4.2 A (10/1000 µs) - clamped voltage seen by protected circuit; determines downstream component voltage stress. |
| PPPM | 400 W (10/1000 µs) - peak transient energy absorption capability; sufficient for ISO 7637-2 Pulse 1 & 2b events. |
| IR @ VWM | <1 µA - ultra-low reverse leakage at rated stand-off; prevents unnecessary power loss in battery-powered systems. |
| TJ max | +150 °C - maximum junction temperature; enables use in under-hood automotive locations without derating. |
| Package | DO-214AC (SMA) - industry-standard surface-mount outline; compatible with automated pick-and-place and reflow. |
Pinout & Package
DO-214AC (SMA) package: molded epoxy case with matte tin-plated leads, polarity indicated by cathode band, weight ≈ 0.060 g, UL 94V-0 flammability rating, JESD201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to ground or lower-potential rail; completes clamping path during transient events. |
| Cathode | High-side transient input terminal | Connected to protected line (e.g., 54 V supply rail); conducts avalanche current when voltage exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including temperature cycling, mechanical shock, and humidity testing per JEDEC standards. |
| Glass-passivated junction | Enhances long-term reliability and stability of breakdown voltage under thermal stress and humidity exposure. |
| <1.0 ps response time | Enables suppression of sub-nanosecond ESD events before sensitive ICs experience damage or latch-up. |
| ISO 7637-2 compliance | Guaranteed performance against standardized automotive transients (Pulse 1, 2a, 2b, 3a, 3b) without external filtering. |
| Moisture sensitivity level 1 | Allows unlimited floor life before reflow; eliminates baking requirement and simplifies SMT manufacturing flow. |
Applications
| Automotive On-Board DC/DC Converter | Industrial Switching Mode Power Supply |
|---|---|
Use Scenario: Protecting 54 V input stage of a buck converter in an ADAS domain controller subjected to load-dump transients up to 120 V. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed at input filter stage to clamp surges before they reach the controller IC and MOSFET gate drivers. Use Value: Limits clamped voltage to 96.3 V, ensuring downstream components remain within absolute maximum ratings during ISO 7637-2 Pulse 2b events. |
Use Scenario: Safeguarding 48–60 V telecom rectifier output against lightning-induced surges and switching transients in base station power modules. IC Role / Device Role / Timing Role: Primary overvoltage clamp on secondary-side DC bus, coordinated with upstream MOVs and fuses for staged protection. Use Value: Delivers 400 W peak pulse power handling with <1 µA leakage, minimizing standby loss while meeting IEC 61000-4-5 Level 3 requirements. |
| LED Driver Power Input Stage | Automotive Body Control Module (BCM) |
Use Scenario: Securing constant-current LED driver input in commercial vehicle lighting where alternator ripple and load dumps occur frequently. IC Role / Device Role / Timing Role: Standoff-rated TVS placed directly after input bulk capacitor to absorb repetitive 10/1000 µs transients without degradation. Use Value: Maintains stable 54 V VWM and low IR to avoid false triggering during normal 12/24/48 V system operation while surviving >10,000 surge cycles. |
Use Scenario: Protecting LIN/CAN interface power rails and microcontroller I/O in BCM units exposed to battery reversal and jump-start conditions. IC Role / Device Role / Timing Role: Secondary-level TVS on regulated 5 V or 3.3 V internal rails, complementing primary front-end protection. Use Value: Leverages AEC-Q101 qualification and –55°C to +150°C operation to ensure functional safety compliance in extended temperature zones. |
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 SMAJ54A | Bidirectional configuration (symmetrical clamping); same VWM (54 V), but higher VC (103 V @ 4.2 A). | Required where bidirectional transients (e.g., AC-coupled signals or floating rails) must be suppressed in both polarities. | Select SMAJ54A only if dual-polarity protection is needed; SMAJ54H offers lower clamping and better unidirectional efficiency. |
| Vishay SMAJ54 | Same unidirectional topology and DO-214AC package; VBR min/max = 60.0–73.3 V, but VC = 98.0 V @ 4.2 A (slightly higher than SMAJ54H's 96.3 V). | Functionally interchangeable in most 54 V rail protection roles, but marginally higher clamping may affect downstream voltage tolerance. | SMAJ54H provides tighter VC specification and AEC-Q101 certification out-of-box, whereas Vishay SMAJ54 requires separate qualification verification. |
Compared with Littelfuse SMAJ54A and Vishay SMAJ54, the SMAJ54H delivers the lowest clamping voltage (96.3 V), guaranteed AEC-Q101 qualification, and optimized leakage performance (<1 µA), making it preferred for high-reliability 54 V automotive and industrial power rail protection where unidirectional surges dominate.
Availability
SMAJ54H is available at Aetrix Electronics and suitable for automotive on-board DC/DC converters, industrial switching mode power supplies, and LED driver power input stages requiring stable component supply with full traceability and lifecycle management.
Supply support for SMAJ54H 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, with global distribution and AEC-Q101-compliant production lines.
The SMAJ series was developed specifically for automotive and industrial transient suppression, emphasizing rugged packaging, fast response, and compliance with ISO 7637-2 and AEC-Q101 - targeting high-volume, mission-critical power rail protection.
FAQ
What is the clamping voltage of SMAJ54H and how is it measured?
The SMAJ54H has a maximum clamping voltage (VC) of 96.3 V, measured at a peak impulse current (IPPM) of 4.2 A using the standardized 10/1000 µs double-exponential waveform per IEC 61000-4-5. This value represents the highest voltage the device allows to pass through to the protected circuit during a transient event, and is confirmed in the manufacturer's electrical specifications table for SMAJ54H at TA = 25°C.
Is SMAJ54H unidirectional or bidirectional, and how can I identify its polarity?
SMAJ54H is a unidirectional TVS diode, intended for DC rail protection where transients occur only in one polarity. Polarity is marked on the DO-214AC (SMA) package by a cathode band - the banded end connects to the protected line (high side), while the unbanded end connects to ground (anode). Bidirectional variants use "CH" or "CAH" suffixes (e.g., SMAJ54CH), which SMAJ54H does not carry.
Does SMAJ54H meet AEC-Q101 requirements, and what tests does that include?
Yes, SMAJ54H is explicitly AEC-Q101 qualified per the manufacturer's documentation. This includes stress tests such as high-temperature operating life (HTOL), temperature cycling (TC), highly accelerated stress test (HAST), mechanical shock, and solder heat resistance - all performed on the DO-214AC packaged device to validate reliability in automotive under-hood environments.
What is the maximum peak pulse power rating for SMAJ54H, and under what conditions?
The SMAJ54H is rated for 400 W peak pulse power (PPPM) under the standard 10/1000 µs waveform condition, as defined in IEC 61000-4-5 and Fig.5 of the datasheet. This rating applies at TA = 25°C and derates linearly above that ambient temperature per the pulse derating curve (Fig.2), reaching ~240 W at 100°C ambient.
Can SMAJ54H be used in place of SMAJ54AH, and what is the key difference?
No - SMAJ54H and SMAJ54AH are distinct variants. SMAJ54H has VBR min/max = 60.0–73.3 V and VC = 96.3 V, while SMAJ54AH has tighter VBR (60.0–66.3 V) and lower VC (87.1 V). The "A" suffix denotes enhanced parameter distribution; substituting SMAJ54H for SMAJ54AH may result in higher clamping voltage and reduced protection margin in designs relying on the tighter spec.
SMAJ54H 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:
- 96.3V
- Current - Peak Pulse (10/1000µs):
- 4.2A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ54H FAQ
1.How can I place an order for SMAJ54H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ54H 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 SMAJ54H reliable?
The price and inventory of SMAJ54H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ54H is usually 5 days.
3.What payment methods are accepted for SMAJ54H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ54H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ54H?
SMAJ54H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ54H 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 SMAJ54H?
For technical support, including SMAJ54H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ54H requirements.
6.How does Aetrix verify that SMAJ54H is sourced from the original manufacturer or authorized distributors?
All SMAJ54H 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 SMAJ54H meets industry standards.
7.What is the process for return or replacement of SMAJ54H?
All SMAJ54H units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ54H, 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 SMAJ54H part is unused and in its original packaging.
Return procedure for SMAJ54H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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