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Taiwan Semiconductor Corporation SMAJ17AH
- Part No.:
- SMAJ17AH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ17AH.pdf
- Description:
- TVS DIODE 17VWM 27.6VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:5,002
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Product details
Overview
SMAJ17AH from Taiwan Semiconductor is a unidirectional 400W transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, with 17V working stand-off voltage (VWM), 18.9–20.9V breakdown voltage (VBR), and 27.6V clamping voltage (VC) at 14.5A peak pulse current. It delivers AEC-Q101 qualification and meets ISO 7637-2 Pulse 1/2a/2b/3a/3b for automotive power line protection.
For engineers reviewing the SMAJ17AH datasheet, SMAJ17AH pinout, SMAJ17AH application, or SMAJ17AH equivalent, key selection criteria include clamping performance under 10/1000μs surge, low leakage (<1μA @ 17V), AEC-Q101 compliance, DO-214AC mechanical compatibility, and bidirectional variant availability (SMAJ17H).
Technical Context
The SMAJ17AH uses a glass-passivated silicon junction optimized for fast transient suppression, achieving sub-1ps response from 0V to VBR min. Its unidirectional configuration features a cathode band marking and supports single-die operation with 150°C maximum junction temperature.
It is rated for 400W peak pulse power (10/1000μs waveform) up to 78V VWM; above that, derating applies-e.g., 300W at 188V. Steady-state power dissipation is 1W, and it withstands 40A non-repetitive forward surge (8.3ms half-sine).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 17 V - Maximum continuous reverse operating voltage before clamping initiates |
| VBR min/max | 18.9 / 20.9 V @ 1 mA - Confirmed breakdown range ensures reliable turn-on margin above VWM |
| VC @ IPPM | 27.6 V @ 14.5 A - Clamping voltage during 10/1000μs surge defines protected circuit voltage ceiling |
| PPPM | 400 W (10/1000μs) - Peak surge energy handling capacity for automotive load dump and ISO 7637-2 transients |
| IR @ VWM | <1 μA - Ultra-low leakage preserves system standby power integrity in battery-coupled applications |
| TJ max | 150 °C - Enables deployment in under-hood automotive environments and high-ambient industrial DC/DC converters |
Pinout & Package
Package: DO-214AC (SMA), surface-mount, matte tin-plated leads, polarity indicated by cathode band. Weight: 0.060 g. Meets UL 94V-0 and JESD201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential side (e.g., ground or return path) in unidirectional TVS configuration |
| Cathode | Reverse-biased clamping terminal | Connected to protected line (e.g., 12V rail); cathode band marks this terminal for correct PCB orientation |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD per stress test requirements |
| Glass passivated junction | Enhances long-term stability and moisture resistance vs. epoxy-passivated alternatives in humid environments |
| ISO 7637-2 compliance | Guarantees robustness against real-world automotive transients: Pulse 1 (inductive switch-off), Pulse 2a/2b (load dump), Pulse 3a/3b (switching noise) |
| Fast response time <1 ps | Ensures clamping activation before sensitive downstream ICs experience overvoltage stress during nanosecond-scale ESD or EFT events |
Applications
| Automotive Power Line Protection | Industrial DC/DC Converter Input |
|---|---|
Use Scenario: Protecting 12V/24V vehicle electronics (ECUs, sensors, infotainment) from load dump and alternator transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed at main power entry point to clamp surges before they reach LDOs, MCUs, or CAN transceivers. Use Value: SMAJ17AH's 27.6V clamping and AEC-Q101 rating ensure sustained operation under ISO 7637-2 Pulse 2b (load dump up to 120V) without degradation. | Use Scenario: Safeguarding isolated DC/DC converter inputs in factory automation controllers exposed to relay-induced spikes. IC Role / Device Role / Timing Role: Primary overvoltage clamp on secondary-side input rail, coordinated with upstream fusing and common-mode chokes. Use Value: 400W peak power rating and 150°C TJ max allow reliable surge absorption in enclosed, thermally constrained enclosures. |
| LED Driver Power Stage | USB-C PD Adapter Secondary Side |
Use Scenario: Suppressing switching transients generated by MOSFETs driving high-power LED strings in streetlight drivers. IC Role / Device Role / Timing Role: Parallel-connected TVS across output capacitor to limit voltage overshoot during rapid current turn-off. Use Value: Sub-1ps response and low 27.6V VC prevent LED string overvoltage failure during PWM dimming transitions. | Use Scenario: Protecting secondary-side synchronous rectifiers and feedback optocouplers in compact USB-C PD adapters. IC Role / Device Role / Timing Role: Unidirectional TVS on +VOUT rail, positioned after transformer but before post-regulation stage. Use Value: 17V VWM aligns with 20V-rated secondary-side components; 1μA IR minimizes quiescent loss in energy-efficient designs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ17H | Higher VBR (18.9–23.1V) and higher VC (30.5V @ 13.1A); same DO-214AC package and 400W rating | Less tight clamping margin; suitable where higher surge tolerance outweighs stricter voltage ceiling | Select SMAJ17H if system can tolerate 30.5V transient ceiling and requires margin against VBR drift at temperature extremes |
| SMBJ17AH | Same electrical specs but in larger DO-214AA (SMB) package; 600W peak power rating (10/1000μs) | Higher thermal mass and power handling; not drop-in due to footprint mismatch | Choose SMBJ17AH only when board layout allows SMB footprint and >400W surge headroom is required |
Compared with SMAJ17H and SMBJ17AH, the SMAJ17AH provides the tightest clamping (27.6V) in the smallest standard surface-mount TVS footprint, making it optimal for space-constrained automotive and portable power designs where precise voltage limiting is critical.
Availability
SMAJ17AH is available at Aetrix Electronics and suitable for automotive ECUs, industrial DC/DC converters, and LED driver power stages requiring stable component supply with AEC-Q101 assurance and ISO 7637-2 compliance.
Supply support for SMAJ17AH 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, serving automotive, industrial, and consumer markets since 1979.
The SMAJ series is part of TSC's AEC-Q101-qualified TVS portfolio, designed specifically for robust transient protection in automotive power distribution networks and industrial power conversion systems.
FAQ
What is the clamping voltage of SMAJ17AH and how is it measured?
The SMAJ17AH has a maximum clamping voltage (VC) of 27.6 V, measured at a peak pulse current (IPPM) of 14.5 A using the standardized 10/1000 μs double-exponential surge waveform. This value is guaranteed across temperature and represents the highest voltage seen at the device terminals during worst-case transient events, directly defining the protection level for downstream circuitry.
Is SMAJ17AH suitable for bidirectional transient protection?
No, SMAJ17AH is a unidirectional TVS diode, intended for DC circuits with defined polarity. For bidirectional protection (e.g., AC lines or data buses), use the SMAJ17H variant or dedicated bidirectional parts like SMAJ17CAH. The cathode band marking on SMAJ17AH confirms its unidirectional orientation and must be correctly routed on PCB.
Does SMAJ17AH meet automotive qualification standards?
Yes, SMAJ17AH is AEC-Q101 qualified and explicitly tested to meet ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b transient immunity requirements. Its construction-including glass passivation, J-STD-020 Level 1 moisture sensitivity, and 150°C TJ max-supports deployment in engine control units, body control modules, and other under-hood or cabin-mounted automotive electronics.
What is the leakage current specification for SMAJ17AH at its working voltage?
SMAJ17AH exhibits a maximum reverse leakage current (IR) of 1 μA when biased at its full working stand-off voltage (VWM) of 17 V, measured at 25°C. This ultra-low leakage ensures minimal impact on battery drain in always-on automotive subsystems and preserves efficiency in low-power industrial sensor nodes.
How does SMAJ17AH differ from SMAJ17A in terms of packaging and marking?
SMAJ17AH uses the DO-214AC (SMA) package with matte tin-plated leads and is marked "BR" on the device body. The "H" suffix denotes halogen-free compliance per IEC 61249-2-21, while the "A" indicates tighter VBR tolerance (18.9–20.9 V vs. 18.9–23.1 V for non-A variants). No functional or electrical difference exists between "SMAJ17AH" and "SMAJ17A-H" - both refer to the same qualified part.
SMAJ17AH 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):
- 17V
- Voltage - Breakdown (Min):
- 18.9V
- Voltage - Clamping (Max) @ Ipp:
- 27.6V
- Current - Peak Pulse (10/1000µs):
- 14.5A
- 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)
SMAJ17AH FAQ
1.How can I place an order for SMAJ17AH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ17AH 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 SMAJ17AH reliable?
The price and inventory of SMAJ17AH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ17AH is usually 5 days.
3.What payment methods are accepted for SMAJ17AH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ17AH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ17AH?
SMAJ17AH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ17AH 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 SMAJ17AH?
For technical support, including SMAJ17AH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ17AH requirements.
6.How does Aetrix verify that SMAJ17AH is sourced from the original manufacturer or authorized distributors?
All SMAJ17AH 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 SMAJ17AH meets industry standards.
7.What is the process for return or replacement of SMAJ17AH?
All SMAJ17AH units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ17AH, 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 SMAJ17AH part is unused and in its original packaging.
Return procedure for SMAJ17AH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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