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Vishay General Semiconductor - Diodes Division SMAJ33AHM3/I
- Part No.:
- SMAJ33AHM3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ33AHM3/I.pdf
- Description:
- TVS DIODE 33VWM 53.3VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:6,076
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Product details
Overview
SMAJ33AHM3/I from Vishay General Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in SMA (DO-214AC) package, designed to protect sensitive electronics against voltage transients induced by inductive load switching and lightning surges. It features a 33 V stand-off voltage (VWM), 53.3 V maximum clamping voltage (VC) at 7.5 A peak pulse current, and 400 W peak pulse power rating with 10/1000 μs waveform - suitable for protecting MOSFETs, ICs, and sensor signal lines in automotive and industrial systems.
For engineers reviewing the SMAJ33AHM3/I datasheet, SMAJ33AHM3/I pinout, SMAJ33AHM3/I application, or SMAJ33AHM3/I equivalent, key selection criteria include its AEC-Q101 qualification, halogen-free RoHS-compliant construction (HM3 suffix), 150 °C max junction temperature, and verified clamping performance under repetitive surge conditions per IEC 61000-4-5.
Technical Context
This TVS diode operates as a fast-acting shunt protection device that clamps transient overvoltages above its breakdown threshold (36.7–40.6 V at 1 mA test current) while maintaining low leakage (<1.0 μA at 33 V). Its glass-passivated junction ensures stable avalanche characteristics and robust surge handling across -55 °C to +150 °C operating range.
The SMAJ33AHM3/I uses a single-junction unidirectional structure with cathode band marking, optimized for DC-biased signal and power lines. Thermal resistance is 120 °C/W (junction-to-ambient) on standard 0.2" × 0.2" copper pads, supporting reliable operation under repeated 0.01% duty-cycle surges up to 400 W below 78 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 33 V - Maximum continuous reverse working voltage before clamping begins; defines safe operating margin for protected circuit. |
| VBR min/max | 36.7 V / 40.6 V at 1 mA - Confirmed breakdown voltage range ensuring consistent turn-on behavior across production lots. |
| VC @ IPPM | 53.3 V at 7.5 A - Clamping voltage under 10/1000 μs surge; determines worst-case overvoltage seen by downstream components. |
| PPPM | 400 W - Peak pulse power handling capability; validates protection level against IEC 61000-4-5 Level 4 surges. |
| IFSM | 40 A - 8.3 ms half-sine surge current rating; supports robustness against inductive switch-off events. |
| TJ max | +150 °C - Maximum junction temperature; enables use in under-hood automotive and high-temperature industrial environments. |
| RθJA | 120 °C/W - Thermal resistance on standard PCB pad layout; informs derating requirements for sustained power dissipation. |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, low-profile case with matte tin-plated leads solderable per J-STD-002 and JESD 22-B102. Polarity indicated by cathode band on unidirectional devices.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to ground or lower-potential rail in unidirectional TVS configuration; carries surge current during clamping. |
| Cathode | Reverse-biased terminal | Connected to protected line (e.g., signal or supply); avalanche breakdown initiates here when VWM is exceeded. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including engine control units and ADAS sensors requiring long-term reliability under thermal cycling and vibration. |
| Halogen-free & RoHS-compliant (HM3) | Meets environmental compliance mandates for global OEMs without compromising surge performance or thermal stability. |
| 400 W peak pulse power (10/1000 μs) | Provides proven protection against severe transients per ISO 7637-2 Pulse 5a and IEC 61000-4-5 surge standards. |
| Low clamping ratio (VC/VBR ≈ 1.39) | Minimizes overvoltage stress on protected ICs compared to higher-ratio alternatives, preserving system-level immunity margins. |
| MSL Level 1 (260 °C peak reflow) | Enables compatibility with standard lead-free SMT assembly processes without moisture sensitivity concerns. |
Applications
| Automotive Power Line Protection | Industrial Sensor Signal Conditioning |
|---|---|
Use Scenario: Protecting 12 V battery-fed ECUs from load dump and alternator ripple transients. IC Role / Device Role / Timing Role: Unidirectional shunt TVS placed between power rail and ground to clamp surges exceeding 33 V. Use Value: Limits peak voltage to ≤53.3 V during 400 W transients, preventing damage to 36 V-rated CAN transceivers and microcontrollers. | Use Scenario: Safeguarding analog output lines of pressure/temperature sensors in factory automation PLCs. IC Role / Device Role / Timing Role: TVS connected across differential signal pair to suppress ESD and cable discharge events. Use Value: Sub-100 ns response time and <1 μA leakage at 33 V ensure minimal signal distortion and no DC offset in precision 4–20 mA loops. |
| Consumer Device USB Port Protection | Telecom Power Supply Input Stage |
Use Scenario: Adding secondary surge protection on VBUS line of USB-C ports in laptops and docking stations. IC Role / Device Role / Timing Role: Standoff-rated TVS placed upstream of USB power delivery controller to absorb residual transients after primary filtering. Use Value: 33 V VWM avoids false triggering during 5 V ±5% regulation, while 53.3 V clamping protects PD controllers rated to 5.5 V absolute max. | Use Scenario: Front-end transient suppression on 48 V telecom rectifier outputs feeding base station RF modules. IC Role / Device Role / Timing Role: Unidirectional TVS mounted at DC input connector to divert lightning-induced surges before entering bulk capacitance. Use Value: 40 A IFSM rating handles high-energy 8.3 ms surges; halogen-free HM3 construction meets IPC-1752A material declaration requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ33AHE3/I | Same electrical specs but RoHS-compliant commercial grade (E3), not halogen-free; lacks AEC-Q101 qualification. | Approved for non-automotive industrial and consumer use only; not validated for automotive temperature cycling or lifetime testing. | Select when halogen-free content or automotive qualification is not required and cost optimization is prioritized. |
| SMBJ33A-HM3 | Higher 600 W PPPM, larger SMB (DO-214AA) package; identical VWM/VC but 20% higher surge current rating (11.3 A). | Better suited for high-energy surge environments (e.g., outdoor telecom cabinets); requires larger PCB footprint and different pad layout. | Choose when system-level surge testing exceeds 400 W requirements and board space allows SMB package. |
Compared with SMAJ33AHE3/I, the SMAJ33AHM3/I adds halogen-free compliance and AEC-Q101 qualification without sacrificing clamping performance; versus SMBJ33A-HM3, it trades surge margin for compact SMA footprint and lower thermal resistance in constrained layouts.
Availability
SMAJ33AHM3/I is available at Aetrix Electronics and suitable for automotive electronics, industrial sensor interfaces, and telecom power supply designs requiring stable component supply, long-term lifecycle support, and certified environmental compliance.
Supply support for SMAJ33AHM3/I 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
Vishay General Semiconductor is a global leader in discrete semiconductors, specializing in diodes, rectifiers, and protection devices with emphasis on reliability, efficiency, and application-specific validation.
The SMAJ series is engineered for robust transient suppression in harsh environments - targeting automotive, industrial, and telecom applications where failure due to voltage surges must be eliminated through proven, standardized protection components.
FAQ
What does the 'HM3' suffix mean in SMAJ33AHM3/I?
The 'HM3' suffix in SMAJ33AHM3/I indicates halogen-free, RoHS-compliant construction with AEC-Q101 qualification. It denotes Vishay's commercial-grade automotive-qualified variant, featuring matte tin-plated leads, MSL Level 1 reflow compatibility, and full compliance with JESD201 Class 2 whisker resistance testing - distinguishing it from E3 (RoHS only) and HE3 (AEC-Q101 but not halogen-free) variants.
Is SMAJ33AHM3/I suitable for bidirectional transient protection?
No, SMAJ33AHM3/I is a unidirectional TVS diode, as confirmed by its part number ending in 'A' (not 'CA') and explicit marking as unidirectional in Vishay's datasheet Table 1. It conducts only in reverse bias above VBR; for bidirectional protection, use SMAJ33CA variants. Using SMAJ33AHM3/I on AC-coupled or floating lines without proper DC bias may result in unintended forward conduction or inadequate clamping.
What is the maximum clamping voltage of SMAJ33AHM3/I under surge conditions?
The maximum clamping voltage of SMAJ33AHM3/I is 53.3 V at 7.5 A peak pulse current (IPPM) with a 10/1000 μs waveform, as specified in Vishay Document Number 88390, page 2. This value represents the worst-case voltage imposed on the protected circuit during a standardized surge event and is critical for verifying compatibility with downstream component absolute maximum ratings.
Does SMAJ33AHM3/I require a heatsink for normal operation?
No, SMAJ33AHM3/I does not require an external heatsink for transient suppression duty cycles (e.g., 0.01% per IEC 61000-4-5), as its thermal design relies on PCB copper pads (0.2" × 0.2" per terminal) to dissipate energy. Its RθJA of 120 °C/W assumes this layout; adding heatsinking provides marginal benefit unless operating under sustained high-duty-cycle or elevated ambient temperatures (>85 °C), where derating per Figure 2 of the datasheet applies.
How does SMAJ33AHM3/I compare to SMAJ33A-E3/61 in terms of packaging and delivery?
SMAJ33AHM3/I and SMAJ33A-E3/61 share identical SMA (DO-214AC) mechanical dimensions and electrical specs, but differ in packaging format and compliance: SMAJ33AHM3/I ships in 13" diameter tape-and-reel (7500 pcs/reel) with halogen-free, AEC-Q101-qualified construction, while SMAJ33A-E3/61 uses 7" reel (1800 pcs/reel) and RoHS-compliant but non-halogen-free, non-automotive-grade materials - making SMAJ33AHM3/I the preferred choice for automotive Tier 1 production and long-lifecycle industrial programs.
SMAJ33AHM3/I Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AC, SMA
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- 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:
- Telecom
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ33AHM3/I FAQ
1.How can I place an order for SMAJ33AHM3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ33AHM3/I 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 SMAJ33AHM3/I reliable?
The price and inventory of SMAJ33AHM3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ33AHM3/I is usually 5 days.
3.What payment methods are accepted for SMAJ33AHM3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ33AHM3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ33AHM3/I?
SMAJ33AHM3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ33AHM3/I 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 SMAJ33AHM3/I?
For technical support, including SMAJ33AHM3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ33AHM3/I requirements.
6.How does Aetrix verify that SMAJ33AHM3/I is sourced from the original manufacturer or authorized distributors?
All SMAJ33AHM3/I 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 SMAJ33AHM3/I meets industry standards.
7.What is the process for return or replacement of SMAJ33AHM3/I?
All SMAJ33AHM3/I units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ33AHM3/I, 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 SMAJ33AHM3/I part is unused and in its original packaging.
Return procedure for SMAJ33AHM3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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