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Vishay General Semiconductor - Diodes Division SMAJ20AHM3/H
- Part No.:
- SMAJ20AHM3/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ20AHM3/H.pdf
- Description:
- TVS DIODE 20VWM 32.4VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:7,643
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Product details
Overview
SMAJ20AHM3/H from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode in SMA (DO-214AC) package, designed for clamping voltage transients on power and signal lines. It features 20 V stand-off voltage (VWM), 22.2–24.5 V breakdown voltage (VBR) at 1 mA, 32.4 V maximum clamping voltage (VC) at 12.3 A peak pulse current (IPPM), and 400 W peak pulse power (10/1000 μs waveform), targeting protection of MOSFETs, ICs, and sensor interfaces in automotive and industrial systems.
For engineers reviewing the SMAJ20AHM3/H datasheet, SMAJ20AHM3/H pinout, SMAJ20AHM3/H application, or SMAJ20AHM3/H equivalent, this page delivers verified electrical parameters, AEC-Q101 qualification status, thermal resistance (RθJA = 120 °C/W), junction temperature range (−55 to +150 °C), and halogen-free RoHS-compliant construction - all critical for ESD/surge protection design-in and long-term supply assurance.
Technical Context
This TVS diode operates as a unidirectional clamping device with cathode-band polarity marking, optimized for fast transient suppression (<1 ps response time implied by silicon junction physics). Its glass-passivated chip junction ensures stable leakage performance (ID ≤ 1.0 μA at VWM) and low incremental surge resistance, enabling reliable energy diversion during 8.3 ms half-sine surges up to 40 A (IFSM).
The SMAJ20AHM3/H is rated for 3.3 W steady-state power dissipation on infinite heatsink at 50 °C ambient and exhibits a positive temperature coefficient of VBR (+0.094 %/°C), supporting predictable voltage margining across operating temperature. Its MSL Level 1 rating (JEDEC J-STD-020) and 260 °C lead-free reflow compatibility confirm suitability for high-volume automated SMT assembly.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 20 V - Maximum continuous reverse operating voltage before significant leakage; defines safe working margin below clamping threshold. |
| VBR min/max | 22.2 V / 24.5 V at IT = 1 mA - Confirmed breakdown window ensuring consistent turn-on behavior across production lots. |
| VC @ IPPM | 32.4 V at 12.3 A - Clamped voltage under standardized 10/1000 μs surge; determines protected circuit's maximum overvoltage exposure. |
| PPPM | 400 W (≤78 V), 300 W (>78 V) - Peak surge power handling capability; defines single-event robustness without thermal runaway. |
| ID @ VWM | ≤1.0 μA - Ultra-low reverse leakage ensures minimal standby power loss and signal integrity in high-impedance circuits. |
| TJ max | +150 °C - Maximum junction temperature rating; enables operation in under-hood automotive or enclosed industrial environments. |
| RθJA | 120 °C/W - Thermal resistance from junction to ambient on standard 0.2" × 0.2" copper pads; informs PCB thermal layout requirements. |
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 lower-potential side (e.g., ground or return path); conducts during forward surge events (IFSM = 40 A). |
| Cathode | Reverse-biased clamping terminal | Connected to protected line (e.g., 24 V rail); initiates avalanche breakdown when transient exceeds VBR, shunting current to anode. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing - supports under-hood and ADAS applications. |
| Halogen-free & RoHS-compliant | HM3 suffix denotes halogen-free molding compound and lead-free terminations - meets global environmental compliance mandates without derating. |
| 400 W peak pulse power | Handles IEC 61000-4-5 Level 4 surges (4 kV/2 Ω) on 24 V systems with margin; validated per 10/1000 μs waveform. |
| Low clamping ratio (VC/VBR ≈ 1.42) | Minimizes overvoltage stress on downstream components - e.g., 32.4 V clamp protects 33 V-rated ICs with 0.6 V safety margin. |
| MSL Level 1 moisture sensitivity | Zero bake requirement prior to reflow; compatible with standard SMT lines using 260 °C peak profile - reduces manufacturing cost and risk. |
Applications
| Automotive Power Rail Protection | Industrial Sensor Interface Protection |
|---|---|
|
Use Scenario: Suppressing load-dump transients (up to 35 V, 100 ms) on 24 V battery-fed ECUs and body control modules. IC Role / Device Role / Timing Role: Unidirectional TVS placed between power rail and ground to clamp overvoltage before it reaches LDOs or microcontrollers. Use Value: Prevents latch-up or permanent damage to 3.3 V/5 V logic supplies by limiting rail excursion to ≤32.4 V during ISO 7637-2 Pulse 5a events. |
Use Scenario: Protecting analog front-ends of pressure/temperature sensors connected to 12 V or 24 V field buses in factory automation. IC Role / Device Role / Timing Role: Standoff-clamp TVS on sensor signal lines (e.g., 4–20 mA loop inputs) to absorb ESD and inductive switching noise. Use Value: Maintains signal fidelity by holding leakage <1 μA at 20 V, while clamping fast transients (<1 ns rise time) to prevent ADC saturation or op-amp rail-to-rail clipping. |
| Consumer Power Adapter Input Stage | Telecom DC Power Feeds |
|
Use Scenario: Secondary-side overvoltage protection in AC/DC adapters for USB-C PD and laptop chargers subjected to lightning-induced surges. IC Role / Device Role / Timing Role: Primary clamping element on +20 V output rail, coordinated with upstream MOVs and fuses. Use Value: Enables compact form factor via SMA package while delivering 400 W surge capacity - eliminates need for larger SMB/SMBF alternatives. |
Use Scenario: Safeguarding -48 V DC power inputs in telecom base station line cards exposed to induced surges from nearby lightning strikes. IC Role / Device Role / Timing Role: Reverse-polarity TVS (cathode to -48 V rail, anode to ground) providing bidirectional-like protection in unidirectional configuration. Use Value: Leverages 20 V VWM and 32.4 V VC to protect -48 V systems with ±10 % tolerance (−43.2 to −52.8 V), ensuring no false triggering during normal operation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ20AHE3/H | Same electrical specs, but RoHS-compliant with brominated flame retardant (non-halogen-free) molding compound. | Acceptable for commercial/industrial use where halogen-free requirement is not mandated. | Select SMAJ20AHE3/H if halogen content is unrestricted and cost optimization is prioritized. |
| SMAJ20A-M3/61 | Identical electrical and thermal specs; differs only in packaging format (61 = 7" tape/reel, 1800 pcs) and absence of AEC-Q101 qualification. | Not qualified for automotive applications; suitable for consumer or non-safety-critical industrial designs. | Choose SMAJ20A-M3/61 for high-volume commercial production where automotive qualification is unnecessary. |
Compared with SMAJ20AHM3/H, SMAJ20AHE3/H offers identical surge performance but lacks halogen-free certification, while SMAJ20A-M3/61 omits AEC-Q101 validation - making SMAJ20AHM3/H the sole choice when both halogen-free compliance and automotive qualification are mandatory.
Availability
SMAJ20AHM3/H is available at Aetrix Electronics and suitable for automotive electronics, industrial sensor interfaces, and telecom power feed protection requiring stable component supply, long-term lifecycle support, and traceable halogen-free sourcing.
Supply support for SMAJ20AHM3/H 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 optimization.
The SMAJ series was engineered for high-energy transient suppression in space-constrained surface-mount applications, targeting automotive, industrial, and communications markets where AEC-Q101 qualification and halogen-free compliance are essential.
FAQ
What is the clamping voltage of SMAJ20AHM3/H at its rated peak pulse current?
The SMAJ20AHM3/H has a maximum clamping voltage (VC) of 32.4 V at its specified peak pulse current (IPPM) of 12.3 A, measured under the standard 10/1000 μs double-exponential surge waveform. This value defines the upper voltage limit imposed on protected circuitry during transient events and is confirmed in Vishay's official datasheet revision 09-Jan-2024 (Document Number: 88390). The clamping performance remains stable across the full operating temperature range of −55 °C to +150 °C.
Is SMAJ20AHM3/H qualified for automotive applications?
Yes, SMAJ20AHM3/H is AEC-Q101 qualified, as explicitly stated in the Vishay datasheet under "Mechanical Data" and "Ordering Information" sections. The "HM3" suffix denotes halogen-free, RoHS-compliant, and AEC-Q101-qualified construction. This qualification covers stress tests including temperature cycling, high-temperature reverse bias (HTRB), and ESD, making SMAJ20AHM3/H suitable for under-hood and ADAS-related automotive systems where reliability under harsh conditions is mandatory.
What does the "HM3" suffix mean in SMAJ20AHM3/H?
The "HM3" suffix in SMAJ20AHM3/H indicates halogen-free, RoHS-compliant construction with AEC-Q101 qualification. Specifically, "H" denotes AEC-Q101 qualification, "M" signifies halogen-free molding compound, and "3" confirms RoHS compliance per EU Directive 2011/65/EU. This distinguishes SMAJ20AHM3/H from variants like SMAJ20A-E3/H (RoHS-compliant but not halogen-free) and SMAJ20A-M3/61 (halogen-free and RoHS-compliant but not AEC-Q101 qualified).
Can SMAJ20AHM3/H be used in bidirectional protection circuits?
No, SMAJ20AHM3/H is a unidirectional TVS diode, as confirmed by its part number suffix "A" (not "CA") and explicit designation in the Vishay datasheet. It functions only in reverse-bias avalanche mode between cathode and anode. For bidirectional protection, the SMAJ20CA variant must be used. Attempting to use SMAJ20AHM3/H in bidirectional configurations risks forward conduction during negative transients, potentially causing failure or inadequate clamping.
What is the thermal resistance and maximum power dissipation of SMAJ20AHM3/H?
SMAJ20AHM3/H has a typical junction-to-ambient thermal resistance (RθJA) of 120 °C/W when mounted on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal, and a steady-state power dissipation (PD) rating of 3.3 W at TA = 50 °C on an infinite heatsink. These values govern PCB layout decisions - insufficient copper area or poor airflow will reduce effective power handling and increase junction temperature beyond the +150 °C absolute maximum.
SMAJ20AHM3/H 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):
- 20V
- Voltage - Breakdown (Min):
- 22.2V
- Voltage - Clamping (Max) @ Ipp:
- 32.4V
- Current - Peak Pulse (10/1000µs):
- 12.3A
- 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)
SMAJ20AHM3/H FAQ
1.How can I place an order for SMAJ20AHM3/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ20AHM3/H 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 SMAJ20AHM3/H reliable?
The price and inventory of SMAJ20AHM3/H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ20AHM3/H is usually 5 days.
3.What payment methods are accepted for SMAJ20AHM3/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ20AHM3/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ20AHM3/H?
SMAJ20AHM3/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ20AHM3/H 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 SMAJ20AHM3/H?
For technical support, including SMAJ20AHM3/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ20AHM3/H requirements.
6.How does Aetrix verify that SMAJ20AHM3/H is sourced from the original manufacturer or authorized distributors?
All SMAJ20AHM3/H 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 SMAJ20AHM3/H meets industry standards.
7.What is the process for return or replacement of SMAJ20AHM3/H?
All SMAJ20AHM3/H units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ20AHM3/H, 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 SMAJ20AHM3/H part is unused and in its original packaging.
Return procedure for SMAJ20AHM3/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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