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Taiwan Semiconductor Corporation SMAJ33H
- Part No.:
- SMAJ33H
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ33H.pdf
- Description:
- TVS DIODE 33VWM 59VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:9,733
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Product details
Overview
SMAJ33H from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for clamping fast transients on DC power lines and signal paths. It features a 33 V working stand-off voltage (VWM), 36.7–44.9 V breakdown voltage (VBR) at 1 mA test current, 59.0 V maximum clamping voltage (VC) at 6.8 A peak impulse current, and 400 W peak pulse power rating with 10/1000 µs waveform - suitable for automotive-grade DC/DC converter input protection.
For engineers reviewing the SMAJ33H datasheet, SMAJ33H pinout, SMAJ33H application, or SMAJ33H equivalent, key selection criteria include clamping voltage margin relative to protected IC VDD rails, leakage current below 1 µA at 33 V, AEC-Q101 qualification for automotive use, and DO-214AC footprint compatibility with high-volume automated assembly.
Technical Context
The SMAJ33H operates as a unidirectional avalanche diode, conducting only in reverse bias above its breakdown threshold to shunt surge energy to ground. Its glass-passivated junction ensures stable VBR tolerance and low leakage (<1 µA at VWM), while sub-1 ps response time enables effective suppression of ESD and ISO 7637-2 Pulse 1/2a/2b/3a/3b transients.
Thermal design relies on its 150 °C maximum junction temperature and 1 W steady-state power dissipation, with derating applied above 25 °C ambient per Fig.2. The device meets JESD201 Class 2 whisker resistance and UL 94V-0 flammability requirements for harsh-environment PCB mounting.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 33 V - Maximum continuous reverse operating voltage before conduction begins; sets upper limit for protected line voltage. |
| VBR min/max | 36.7 V / 44.9 V at 1 mA - Confirmed breakdown range ensures reliable turn-on without premature clamping. |
| VC @ IPPM | 59.0 V at 6.8 A - Clamping voltage under 10/1000 µs surge defines worst-case overvoltage seen by downstream circuitry. |
| PPPM | 400 W (10/1000 µs) - Peak surge power handling capacity validated per REA standard waveform. |
| IR @ VWM | <1 µA - Negligible leakage preserves efficiency in battery-powered or low-quiescent systems. |
| TJ max | 150 °C - Enables operation in under-hood automotive environments and industrial power supplies. |
| Package | DO-214AC (SMA) - Standardized 2-pin SMD outline with cathode band marking; compatible with IPC-7351B footprint. |
Pinout & Package
DO-214AC (SMA) package: surface-mount, molded plastic case with matte tin-plated leads, polarity indicated by cathode band. Weight ≈ 0.060 g. Meets J-STD-020 moisture sensitivity level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to ground or lower-potential node in unidirectional configuration; completes surge path during clamping. |
| Cathode | Reverse-biased clamping terminal | Connected to protected line (e.g., 33 V rail); avalanche conduction initiates here when voltage exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive electronics per stress test requirements including HTOL, TC, UHAST, and ESD-HBM/MM. |
| Glass passivated junction | Ensures long-term VBR stability and low IR drift across temperature and lifetime, critical for safety-critical protection. |
| Fast response time <1 ps | Enables suppression of nanosecond-scale ESD events before sensitive ICs experience overstress. |
| ISO 7637-2 compliance | Rated for Pulse 1 (inductive load dump), Pulse 2a/2b (switching transients), and Pulse 3a/3b (capacitive coupling), covering full vehicle electrical disturbance profile. |
| Halogen-free & RoHS | Meets IEC 61249-2-21 and EU RoHS Directive 2011/65/EU for environmentally compliant manufacturing. |
Applications
| Automotive On-Board DC/DC Converter Input Protection | Industrial SMPS Secondary-Side Transient Suppression |
|---|---|
Use Scenario: Protects 3.3 V or 5 V buck converter IC inputs against load-dump-induced surges on 12 V or 24 V vehicle battery rails. IC Role / Device Role / Timing Role: Unidirectional TVS placed between input rail and ground, clamping transients within 1 ps to limit voltage to ≤59.0 V. Use Value: Prevents latch-up or gate oxide damage in synchronous rectifier MOSFETs and controller ICs during ISO 7637-2 Pulse 1 events. | Use Scenario: Shields feedback optocoupler and error amplifier inputs in isolated flyback converters from secondary-side coupling transients. IC Role / Device Role / Timing Role: Mounted across output capacitor or feedback divider, absorbing coupled noise from primary-side switching edges. Use Value: Maintains regulation accuracy and prevents false triggering of overvoltage protection by limiting transient excursions to <60 V. |
| LED Driver Power Input Clamp | USB-C PD Adapter Output Line Protection |
Use Scenario: Installed on constant-current LED driver input to absorb inductive kickback from relay-controlled dimming circuits. IC Role / Device Role / Timing Role: Connected anode-to-ground, cathode-to-33 V supply rail; conducts only during >36.7 V transients. Use Value: Eliminates visible flicker or driver shutdown caused by 100–500 V, 10/1000 µs surges from mechanical switching. | Use Scenario: Safeguards USB-C PD port output (e.g., 20 V PPS rail) against hot-swap and cable-insertion transients. IC Role / Device Role / Timing Role: Placed between VBUS and GND on PD controller output side; leverages 33 V VWM to avoid conduction during normal 20 V operation. Use Value: Ensures robustness against ±15 kV contact ESD (IEC 61000-4-2) and maintains <1 µA leakage to preserve PD negotiation timing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ33AH | Narrower VBR range (36.7–40.6 V vs. 36.7–44.9 V); tighter 10% tolerance. | Better suited for precision-clamp designs where upper VC margin must be minimized. | Select SMAJ33AH when clamping voltage consistency is prioritized over cost; SMAJ33H offers broader VBR for higher production yield. |
| SMBJ33A | Same VWM/VBR specs but in larger DO-214AA (SMB) package; 600 W PPPM rating. | Higher surge margin for infrequent high-energy events; requires larger PCB area. | Choose SMBJ33A only if system-level testing shows 400 W insufficient; SMAJ33H provides optimal balance of size, cost, and 400 W capability. |
Compared with SMAJ33AH, the SMAJ33H offers wider VBR tolerance for improved manufacturing yield, while compared with SMBJ33A, it delivers identical electrical protection in a 30% smaller DO-214AC footprint - making SMAJ33H the preferred choice for space-constrained automotive and industrial DC/DC modules requiring AEC-Q101 compliance.
Availability
SMAJ33H is available at Aetrix Electronics and suitable for automotive on-board chargers, industrial switch-mode power supplies, LED lighting drivers, and USB-C PD adapter designs requiring stable component supply with AEC-Q101 qualification and DO-214AC packaging.
Supply support for SMAJ33H 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 AEC-Q101-compliant automotive and industrial transient suppression, emphasizing reliability under thermal cycling, humidity, and repetitive surge stress in compact surface-mount form factors.
FAQ
What is the maximum clamping voltage of the SMAJ33H under a 10/1000 µs surge?
The SMAJ33H has a maximum clamping voltage (VC) of 59.0 V when subjected to its rated peak impulse current of 6.8 A using the standardized 10/1000 µs waveform. This value is measured per Figure 5 in the official Taiwan Semiconductor datasheet and defines the highest voltage that will appear across the protected line during surge conduction. Designers must ensure downstream components tolerate up to 59.0 V transient exposure.
Is the SMAJ33H suitable for bidirectional transient protection?
No, the SMAJ33H is a unidirectional TVS diode intended for DC line protection with defined polarity - cathode connects to the protected line, anode to ground. For bidirectional applications such as AC lines or data bus protection, Taiwan Semiconductor specifies the SMAJ33H's counterpart SMAJ33CH (with CH suffix), which provides symmetrical clamping in both directions. Using SMAJ33H in bidirectional configurations risks failure during positive half-cycle surges.
Does the SMAJ33H meet automotive qualification standards?
Yes, the SMAJ33H is explicitly AEC-Q101 qualified per the manufacturer's documentation, having passed stress tests including high-temperature operating life (HTOL), temperature cycling (TC), unbiased highly accelerated stress test (UHAST), and human-body-model ESD (HBM). This certification confirms suitability for automotive powertrain, body electronics, and infotainment systems where reliability under thermal and electrical stress is mandatory.
What is the leakage current specification for the SMAJ33H at its working voltage?
The SMAJ33H exhibits a maximum reverse leakage current (IR) of 1 µA when biased at its 33 V working stand-off voltage (VWM), measured at 25 °C ambient. This ultra-low leakage ensures minimal power loss in always-on systems such as automotive telematics modules or industrial sensors, and avoids unintended discharge of hold-up capacitors in standby modes.
Can the SMAJ33H be used in place of the SMAJ33AH?
Yes, the SMAJ33H can serve as a functional alternative to the SMAJ33AH in most applications, though with a wider VBR range (36.7–44.9 V vs. 36.7–40.6 V) and slightly higher clamping voltage (59.0 V vs. 53.3 V). Designers should verify that the increased VC margin does not violate downstream IC absolute maximum ratings; where tight clamping control is critical, SMAJ33AH remains preferable, but SMAJ33H offers better yield and cost for general-purpose protection.
SMAJ33H 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):
- 33V
- Voltage - Breakdown (Min):
- 36.7V
- Voltage - Clamping (Max) @ Ipp:
- 59V
- Current - Peak Pulse (10/1000µs):
- 6.8A
- 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)
SMAJ33H FAQ
1.How can I place an order for SMAJ33H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ33H 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 SMAJ33H reliable?
The price and inventory of SMAJ33H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ33H is usually 5 days.
3.What payment methods are accepted for SMAJ33H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ33H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ33H?
SMAJ33H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ33H 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 SMAJ33H?
For technical support, including SMAJ33H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ33H requirements.
6.How does Aetrix verify that SMAJ33H is sourced from the original manufacturer or authorized distributors?
All SMAJ33H 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 SMAJ33H meets industry standards.
7.What is the process for return or replacement of SMAJ33H?
All SMAJ33H units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ33H, 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 SMAJ33H part is unused and in its original packaging.
Return procedure for SMAJ33H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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