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Taiwan Semiconductor Corporation SMAJ33AH
- Part No.:
- SMAJ33AH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ33AH.pdf
- Description:
- TVS DIODE 33VWM 53.3VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:7,500
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Product details
Overview
SMAJ33AH from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for robust overvoltage protection in DC power rails and signal lines. It features a 33 V working stand-off voltage (VWM), 36.7–40.6 V breakdown voltage (VBR) at 1 mA, clamps to ≤53.3 V at 7.5 A peak impulse current, and delivers 400 W peak pulse power (10/1000 µs waveform). It is widely deployed in automotive-grade DC/DC converters and industrial SMPS inputs.
For engineers reviewing the SMAJ33AH datasheet, SMAJ33AH pinout, SMAJ33AH application, or SMAJ33AH equivalent, key selection criteria include clamping voltage margin vs. protected IC VDD, leakage current at operating voltage, AEC-Q101 qualification status, and DO-214AC package thermal performance under repetitive surge conditions.
Technical Context
The SMAJ33AH employs a glass-passivated silicon junction optimized for fast transient response (<1.0 ps rise time from 0 V to VBR) and low leakage (<1 µA at 33 V). Its unidirectional configuration provides asymmetric clamping-forward conduction limited to 3.5 V at 25 A-making it suitable for polarity-sensitive rail protection where reverse blocking is required.
It meets ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b test requirements for automotive electronics and operates across –55 °C to +150 °C junction temperature. The device is rated for 40 A non-repetitive forward surge (8.3 ms half-sine) and derates linearly above 25 °C ambient per published pulse derating curve.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 33 V - Maximum continuous DC or RMS voltage the device blocks without clamping; sets upper limit of protected circuit's normal operating range. |
| VBR min/max | 36.7 V / 40.6 V @ 1 mA - Confirmed breakdown threshold window; ensures reliable turn-on before downstream component overvoltage. |
| VC @ IPPM | ≤53.3 V @ 7.5 A - Clamped voltage during 10/1000 µs surge; must stay below protected IC's absolute maximum rating. |
| PPPM | 400 W (10/1000 µs) - Peak surge energy handling capacity; defines survivability against common load-dump or ESD-like transients. |
| IR @ VWM | ≤1 µA - Reverse leakage at working voltage; critical for low-power standby circuits and battery-backed systems. |
| TJ max | +150 °C - Maximum junction temperature; enables use in under-hood automotive environments and high-ambient industrial enclosures. |
| Package | DO-214AC (SMA) - Standardized surface-mount outline with 0.060 g mass; supports automated placement and meets UL 94V-0 flammability. |
Pinout & Package
DO-214AC (SMA) package: molded epoxy case with matte tin-plated leads, cathode band marking polarity, JESD201 Class 2 whisker resistance, and moisture sensitivity level (MSL) 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Input/Line side (for unidirectional operation) | Connected to source of transient threat (e.g., battery feed); conducts only during reverse-biased clamping event. |
| Cathode | Protected rail side | Connected to downstream circuit (e.g., DC/DC input); establishes reference for clamping action and polarity-sensitive protection. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive electronics per stress test requirements including HTOL, TCT, and ESD; enables use in engine control, body electronics, and ADAS modules. |
| Glass passivated junction | Enhances long-term reliability and stability of VBR and leakage under thermal cycling and humidity exposure. |
| ISO 7637-2 compliance | Guarantees immunity to standardized automotive transients (Pulse 1/2a/2b/3a/3b); eliminates need for additional external filtering in certified designs. |
| Fast response time | <1.0 ps from 0 V to VBR min - Enables clamping before sensitive downstream components experience overvoltage stress. |
| RoHS & halogen-free | Complies with IEC 61249-2-21 and EU RoHS Directive; supports environmentally compliant manufacturing and end-of-life recycling. |
Applications
| Automotive DC/DC Converters | Industrial SMPS Inputs |
|---|---|
Use Scenario: Protection of 24 V nominal input stage in buck converter powering infotainment head units. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery feed and converter input capacitor to clamp load-dump spikes up to ±125 V. Use Value: Limits clamped voltage to ≤53.3 V, well below 60 V absolute maximum rating of typical 40 V MOSFETs and controllers used in such converters. |
Use Scenario: Input rail protection in 48 V telecom rectifier module exposed to lightning-induced surges on AC mains side. IC Role / Device Role / Timing Role: Primary surge suppression device upstream of bridge rectifier and bulk capacitor; absorbs 400 W transient energy. Use Value: Withstands 7.5 A peak impulse current while maintaining <1 µA leakage at 33 V, preserving efficiency in standby mode. |
| LED Driver Power Supplies | On-Board Charger (OBC) Control Circuits |
Use Scenario: Standby power rail protection in outdoor LED streetlight driver subjected to induced surges from nearby lightning strikes. IC Role / Device Role / Timing Role: Clamps transients on 12 V auxiliary supply feeding microcontroller and gate drivers. Use Value: Fast <1.0 ps response ensures clamping occurs before 3.3 V logic ICs experience latch-up or permanent damage. |
Use Scenario: Signal line protection for CAN bus interface and isolated gate drive feedback in electric vehicle OBC control board. IC Role / Device Role / Timing Role: Secondary-level TVS on low-voltage control rails (e.g., 5 V, 3.3 V) to suppress coupling from high-power switching nodes. Use Value: Low 1 µA leakage prevents false wake-up in sleep-mode CAN transceivers; MSL-1 rating supports reflow-compatible assembly. |
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 SMAJ33A | Identical VWM (33 V), VBR (36.7–40.6 V), VC (≤53.3 V), and DO-214AC package; same 400 W PPPM rating. | No functional difference; fully interchangeable in layout and electrical behavior. | Select when dual-sourcing or lead-time constraints require alternate vendor fulfillment. |
| ON Semiconductor SMAJ33A | VBR min/max matches (36.7–40.6 V); VC = 53.3 V; same 400 W rating and DO-214AC footprint; AEC-Q101 qualified. | Same automotive and industrial use cases; validated to identical ISO 7637-2 pulses. | Preferred for designs already using ON Semi ecosystem or requiring consolidated supplier agreements. |
Compared with SMAJ33AH, both Littelfuse SMAJ33A and ON Semiconductor SMAJ33A deliver identical clamping performance, thermal derating, and automotive qualification-enabling drop-in substitution without layout or firmware changes, while offering supply chain diversification.
Availability
SMAJ33AH is available at Aetrix Electronics and suitable for automotive DC/DC converters, industrial SMPS inputs, and LED driver power supplies requiring stable component supply, AEC-Q101 compliance, and consistent DO-214AC packaging.
Supply support for SMAJ33AH 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, and power devices since 1979.
The SMAJ series was developed specifically for high-reliability transient suppression in automotive and industrial power systems, emphasizing AEC-Q101 qualification, ISO 7637-2 compliance, and robust glass-passivated junction technology.
FAQ
What is the maximum clamping voltage of SMAJ33AH under standard test conditions?
The SMAJ33AH has a maximum clamping voltage (VC) of 53.3 V when subjected to a 7.5 A peak impulse current with a 10/1000 µs waveform. This value is measured at TA = 25 °C and represents the upper bound of voltage seen by downstream circuitry during surge events. Designers must ensure this clamped level remains below the absolute maximum ratings of protected components. The SMAJ33AH consistently achieves this performance across its qualified operating temperature range.
Is SMAJ33AH suitable for bidirectional transient protection?
No, SMAJ33AH is a unidirectional TVS diode and is not rated for bidirectional operation. Its electrical specifications-including breakdown voltage, clamping behavior, and leakage-are defined only for reverse-biased conduction. For bidirectional protection, Taiwan Semiconductor offers the SMAJ33CH variant (with CH suffix), which provides symmetrical clamping in both polarities. Using SMAJ33AH in a bidirectional configuration may result in forward conduction failure or inadequate protection during positive transients.
Does SMAJ33AH meet automotive qualification standards?
Yes, SMAJ33AH is AEC-Q101 qualified and meets ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b requirements for automotive electronic components. It is rated for operation from –55 °C to +150 °C junction temperature and undergoes rigorous stress testing including high-temperature operating life (HTOL), temperature cycling (TCT), and electrostatic discharge (ESD). These qualifications make SMAJ33AH appropriate for under-hood and chassis-mounted applications in passenger vehicles and commercial EVs.
What is the leakage current specification for SMAJ33AH at its working voltage?
The SMAJ33AH exhibits a maximum reverse leakage current (IR) of 1 µA when biased at its 33 V working stand-off voltage (VWM) and tested at TA = 25 °C. This ultra-low leakage ensures minimal power loss in always-on or battery-powered systems and avoids unintended loading of precision reference or sensor bias networks. The specification is guaranteed across the full operating temperature range and supports energy-efficient design in automotive and industrial standby modes.
What package type does SMAJ33AH use, and is it compatible with standard SMT assembly processes?
SMAJ33AH uses the DO-214AC (SMA) surface-mount package, featuring matte tin-plated leads that comply with J-STD-002 solderability requirements. Its MSL Level 1 rating means it can be stored indefinitely at ambient conditions without baking prior to reflow. The package is fully compatible with standard pick-and-place equipment and lead-free reflow profiles, supporting high-yield automated assembly in automotive and industrial manufacturing lines. The cathode band marking ensures correct orientation during placement.
SMAJ33AH 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:
- 53.3V
- Current - Peak Pulse (10/1000µs):
- 7.5A
- 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)
SMAJ33AH FAQ
1.How can I place an order for SMAJ33AH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ33AH 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 SMAJ33AH reliable?
The price and inventory of SMAJ33AH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ33AH is usually 5 days.
3.What payment methods are accepted for SMAJ33AH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ33AH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ33AH?
SMAJ33AH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ33AH 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 SMAJ33AH?
For technical support, including SMAJ33AH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ33AH requirements.
6.How does Aetrix verify that SMAJ33AH is sourced from the original manufacturer or authorized distributors?
All SMAJ33AH 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 SMAJ33AH meets industry standards.
7.What is the process for return or replacement of SMAJ33AH?
All SMAJ33AH units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ33AH, 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 SMAJ33AH part is unused and in its original packaging.
Return procedure for SMAJ33AH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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