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Vishay General Semiconductor - Diodes Division SMBJ18AHM3_A/H
- Part No.:
- SMBJ18AHM3_A/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ18AHM3_A/H.pdf
- Description:
- TVS DIODE 18VWM 29.2VC DO214AA
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
SMBJ18AHM3_A/H from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode in SMB (DO-214AA) package, designed for robust overvoltage protection of sensitive electronics. It features 18 V stand-off voltage (VWM), 20.0–22.1 V breakdown voltage (VBR) at 1 mA, 29.2 V maximum clamping voltage (VC) at 20.5 A peak pulse current (IPPM), and 600 W peak pulse power rating with 10/1000 μs waveform - deployed on power rails and signal lines in industrial motor drives and automotive body control modules.
For engineers reviewing the SMBJ18AHM3_A/H datasheet, SMBJ18AHM3_A/H pinout, SMBJ18AHM3_A/H application, or SMBJ18AHM3_A/H equivalent, key selection criteria include clamping performance under 20.5 A surge, thermal resistance (RθJA = 100 °C/W), unidirectional polarity with cathode band marking, and halogen-free RoHS-compliant construction per JESD201 Class 2 whisker testing.
Technical Context
This TVS diode operates as a voltage-clamped shunt protector: when transient voltage exceeds VBR, it avalanches to divert surge current away from downstream ICs or MOSFETs. Its glass-passivated junction ensures stable breakdown characteristics and low leakage (<1.0 μA at VWM), while the SMB package supports automated placement and meets MSL Level 1 reflow profile (260 °C peak).
The device is rated for -55 °C to +150 °C operating junction temperature, with 5.0 W steady-state power dissipation at TA = 50 °C and 100 A non-repetitive forward surge capability (8.3 ms half-sine). Its 0.092 %/°C VBR temperature coefficient enables predictable performance across thermal gradients in embedded power systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18 V - maximum continuous reverse working voltage before clamping initiates; defines safe operating margin for 15–18 V DC rails. |
| VBR (min/max) | 20.0 V / 22.1 V at IT = 1 mA - guaranteed avalanche onset range; ensures reliable triggering without premature conduction. |
| VC @ IPPM | 29.2 V at 20.5 A - clamped voltage during 10/1000 μs surge; limits stress on protected 24 V logic or gate drivers. |
| PPPM | 600 W - peak pulse power handling with 10/1000 μs waveform; supports IEC 61000-4-5 Level 3/4 surge immunity. |
| ID @ VWM | ≤1.0 μA - ultra-low reverse leakage at stand-off voltage; prevents parasitic loading on high-impedance sensor interfaces. |
| TJ max. | +150 °C - maximum junction temperature; enables use in under-hood automotive or enclosed industrial enclosures. |
| RθJA | 100 °C/W - thermal resistance junction-to-ambient on standard 0.2" × 0.2" copper pads; informs PCB thermal pad design. |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, halogen-free, RoHS-compliant, matte tin-plated leads. Cathode indicated by molded band on case.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry terminal during forward conduction | Connected to system ground or low-side return path; forms shunt path during transients. |
| Cathode | Current exit terminal during forward conduction; marked with band | Connected to protected line (e.g., 24 V rail); avalanche occurs when cathode-to-anode voltage exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| 600 W peak pulse power (10/1000 μs) | Enables compliance with IEC 61000-4-5 surge immunity up to 1 kV open-circuit / 0.5 kV source impedance. |
| Glass-passivated chip junction | Ensures long-term stability of VBR and low parametric drift over temperature and lifetime cycling. |
| MSL Level 1 (260 °C peak) | Supports standard lead-free reflow without popcorn cracking or delamination risk. |
| AEC-Q101 qualified variant available | HM3 suffix indicates qualification for automotive applications including BCM, lighting, and infotainment power domains. |
| Low incremental surge resistance | Minimizes VC overshoot during fast-rising transients (e.g., inductive switch-off in solenoid drivers). |
Applications
| Industrial Motor Drives | Automotive Body Control Modules |
|---|---|
|
Use Scenario: Protection of 24 V DC input stage against load dump and inductive kickback from relay coils and solenoids. IC Role / Device Role / Timing Role: Unidirectional shunt TVS placed between VIN and GND, clamping transients within 1 ns response time. Use Value: Limits voltage to ≤29.2 V during 20.5 A surges, preventing damage to upstream DC-DC controllers and microcontrollers. |
Use Scenario: Guarding LIN bus transceiver power pins against battery voltage spikes during jump-start or alternator load dump. IC Role / Device Role / Timing Role: Standoff-rated TVS on VCC rail of LIN PHY IC, activated only during overvoltage events >22.1 V. Use Value: Maintains <1.0 μA leakage at 18 V nominal, avoiding false wake-up or supply loading in sleep-mode vehicle networks. |
| Consumer Power Adapters | Telecom PoE Injectors |
|
Use Scenario: Secondary-side overvoltage suppression on 12–19 V output rails of AC/DC adapters for laptops and monitors. IC Role / Device Role / Timing Role: Fast-response clamp parallel to output capacitor, triggered by flyback transformer ringing or regulation fault. Use Value: 29.2 V clamping ensures downstream USB-PD or display interface ICs remain within absolute maximum ratings. |
Use Scenario: Input-stage surge protection on 48 V PSE side of IEEE 802.3af/at PoE injectors exposed to lightning-induced surges. IC Role / Device Role / Timing Role: Primary-line TVS on DC input before DC-DC isolation stage, absorbing differential-mode transients. Use Value: 600 W rating handles 10/1000 μs surges up to 20.5 A without degradation, supporting EN 61000-4-5 compliance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ18A-E3/52 | Same electrical specs (VWM = 18 V, VC = 29.2 V), but RoHS-compliant commercial grade without halogen-free certification. | Lacks JESD201 Class 2 whisker resistance and halogen-free compliance required for automotive Tier-1 BOMs. | Select SMBJ18AHM3_A/H when halogen-free and enhanced reliability per AEC-Q101 are mandatory. |
| SMBJ18CAHM3_A/H | Bidirectional version: symmetric VBR (20.0–22.1 V) in both directions; same package and HM3 suffix. | Required for AC-coupled or bidirectional signal lines (e.g., RS-485, CAN FD), not suitable for DC rail protection where polarity matters. | Choose SMBJ18CAHM3_A/H only for applications needing symmetrical clamping on differential pairs or AC inputs. |
Compared with SMBJ18A-E3/52, SMBJ18AHM3_A/H adds halogen-free construction and whisker-resistant plating for harsh environments; versus SMBJ18CAHM3_A/H, it provides polarity-aware unidirectional clamping essential for DC power rail protection.
Availability
SMBJ18AHM3_A/H is available at Aetrix Electronics and suitable for industrial motor drives, automotive body control modules, and telecom PoE injectors requiring stable component supply with halogen-free compliance and AEC-Q101 traceability.
Supply support for SMBJ18AHM3_A/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, MOSFETs, and protection devices with emphasis on reliability and automotive-grade qualification.
The SMBJ series delivers standardized 600 W transient suppression in SMB package for cost-sensitive, high-volume industrial and automotive applications - engineered for repeatable clamping performance and automated assembly compatibility.
FAQ
What is the clamping voltage of SMBJ18AHM3_A/H at its rated peak pulse current?
The SMBJ18AHM3_A/H has a maximum clamping voltage (VC) of 29.2 V at 20.5 A peak pulse current (IPPM) with a 10/1000 μs waveform. This value is measured under standardized test conditions and defines the upper voltage limit imposed on protected circuitry during surge events. The SMBJ18AHM3_A/H maintains this clamping performance across its full operating temperature range, ensuring consistent protection in demanding environments.
Is SMBJ18AHM3_A/H suitable for automotive applications?
Yes, SMBJ18AHM3_A/H is halogen-free, RoHS-compliant, and AEC-Q101 qualified - confirmed by the HM3 suffix and Vishay's ordering documentation. It meets automotive requirements for thermal cycling, mechanical shock, and long-term reliability in body control modules, lighting drivers, and infotainment power supplies. The SMBJ18AHM3_A/H is explicitly listed in Vishay's AEC-Q101 qualified product matrix for transient suppression.
How does the SMBJ18AHM3_A/H differ from the SMBJ18A-E3/52 variant?
The SMBJ18AHM3_A/H differs from SMBJ18A-E3/52 in three key ways: it uses halogen-free molding compound, meets JESD201 Class 2 whisker resistance, and carries AEC-Q101 qualification. Electrically, both share identical VWM (18 V), VBR (20.0–22.1 V), and VC (29.2 V) specs. The SMBJ18AHM3_A/H is specified for automotive and high-reliability industrial use, whereas SMBJ18A-E3/52 targets general commercial applications.
What is the thermal resistance of SMBJ18AHM3_A/H, and how does it affect PCB layout?
The SMBJ18AHM3_A/H has a typical junction-to-ambient thermal resistance (RθJA) of 100 °C/W when mounted on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal. This value assumes minimum recommended pad layout per Vishay's datasheet - underscoring the need for adequate copper area to maintain TJ ≤ 150 °C under sustained 5.0 W dissipation. Reducing pad size increases RθJA and risks thermal runaway during repetitive surges.
Does SMBJ18AHM3_A/H have polarity marking, and how is it identified?
Yes, SMBJ18AHM3_A/H is unidirectional and features a visible cathode band on the SMB (DO-214AA) package body - located adjacent to the cathode terminal. This band must be oriented toward the higher-potential side of the protected line (e.g., 24 V rail), while the anode connects to ground or return. Bidirectional variants like SMBJ18CAHM3_A/H omit this marking, confirming SMBJ18AHM3_A/H's polarity-specific installation requirement.
SMBJ18AHM3_A/H Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AA, SMB
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 18V
- Voltage - Breakdown (Min):
- 20V
- Voltage - Clamping (Max) @ Ipp:
- 29.2V
- Current - Peak Pulse (10/1000µs):
- 20.5A
- Power - Peak Pulse:
- 600W
- 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-214AA (SMB)
SMBJ18AHM3_A/H FAQ
1.How can I place an order for SMBJ18AHM3_A/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ18AHM3_A/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 SMBJ18AHM3_A/H reliable?
The price and inventory of SMBJ18AHM3_A/H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ18AHM3_A/H is usually 5 days.
3.What payment methods are accepted for SMBJ18AHM3_A/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ18AHM3_A/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ18AHM3_A/H?
SMBJ18AHM3_A/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ18AHM3_A/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 SMBJ18AHM3_A/H?
For technical support, including SMBJ18AHM3_A/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ18AHM3_A/H requirements.
6.How does Aetrix verify that SMBJ18AHM3_A/H is sourced from the original manufacturer or authorized distributors?
All SMBJ18AHM3_A/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 SMBJ18AHM3_A/H meets industry standards.
7.What is the process for return or replacement of SMBJ18AHM3_A/H?
All SMBJ18AHM3_A/H units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ18AHM3_A/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 SMBJ18AHM3_A/H part is unused and in its original packaging.
Return procedure for SMBJ18AHM3_A/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ18AHM3_A/H Tags
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DESD3V3E1BL-7B
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