My Inquiry
My Account
Vishay General Semiconductor - Diodes Division SMBJ18A-M3/5B
;;2.jpg)
- Part No.:
- SMBJ18A-M3/5B
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ18A-M3/5B.pdf
- Description:
- TVS DIODE 18VWM 29.2VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:8,738
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMBJ18A-M3/5B from Vishay General Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in SMB (DO-214AA) package, designed for clamping voltage transients on power and signal lines. It features a 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 (10/1000 µs waveform), protecting MOSFETs and ICs in industrial power supplies.
For engineers reviewing the SMBJ18A-M3/5B datasheet, SMBJ18A-M3/5B pinout, SMBJ18A-M3/5B application, or SMBJ18A-M3/5B equivalent, key selection criteria include clamping voltage margin vs. protected device's absolute maximum rating, thermal derating above 25 °C, unidirectional polarity marking (cathode band), and halogen-free RoHS compliance per M3 suffix - critical for automotive and industrial PCB reliability audits.
Technical Context
This TVS diode operates as a voltage-clamping protection device, conducting only when reverse voltage exceeds its breakdown threshold (VBR), thereby shunting surge energy to ground. Its glass-passivated junction ensures stable leakage (<1.0 µA at VWM) and fast response time (<1.0 ps), enabling effective suppression of ESD and inductive switching transients.
The SMBJ18A-M3/5B uses a single-junction PN structure with cathode-band polarity identification, rated for 150 °C max junction temperature and 100 A non-repetitive forward surge (IFSM). Thermal resistance is 100 °C/W junction-to-ambient (RθJA) on standard 5.0 mm × 5.0 mm copper pads, requiring layout-aware thermal design for sustained 5.0 W power dissipation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18 V - Maximum continuous reverse operating voltage before clamping begins; must exceed normal circuit operating voltage by ≥10 %. |
| VBR (min/max) | 20.0 V / 22.1 V at 1 mA - Confirmed breakdown range defines turn-on consistency; tighter tolerance improves system-level overvoltage margin control. |
| VC @ IPPM | 29.2 V at 20.5 A - Clamped voltage during 10/1000 µs surge; determines whether protected IC's absolute max rating (e.g., 30 V) remains unexceeded. |
| PPPM | 600 W - Peak pulse power handling capability under standardized 10/1000 µs waveform; validates robustness against IEC 61000-4-5 Level 3 surges. |
| ID @ VWM | ≤1.0 µA - Reverse leakage at stand-off voltage; low value minimizes standby power loss and avoids false triggering in high-impedance sensor lines. |
| TJ max. | +150 °C - Maximum junction temperature; enables operation in under-hood automotive or enclosed industrial enclosures without active cooling. |
| Package | SMB (DO-214AA) - Surface-mount outline with 5.59 mm × 4.06 mm footprint and 2.20 mm height; compatible with automated pick-and-place and reflow profiles up to 260 °C peak. |
Pinout & Package
Package: SMB (DO-214AA), molded plastic case with matte tin-plated leads, MSL Level 1 compliant, halogen-free and RoHS-compliant per M3 suffix.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential side (e.g., GND or return path); carries full surge current during clamping event. |
| Cathode | Reverse-biased clamping terminal | Marked with band; connected to protected line (e.g., 12 V rail); initiates avalanche conduction when VAK > VBR. |
Key Features
| Feature | Design Value |
|---|---|
| 600 W peak pulse power (10/1000 µs) | Validated clamping performance against lightning-induced surges per IEC 61000-4-5, supporting industrial-grade immunity without external heat sinking. |
| Glass passivated chip junction | Ensures long-term parameter stability and low leakage drift across temperature and humidity stress, critical for 10+ year field deployments. |
| Halogen-free, RoHS-compliant (M3 suffix) | Meets EU Directive 2011/65/EU and IPC-1752A material declarations; eliminates brominated flame retardants for safer end-of-life processing. |
| MSL Level 1, 260 °C peak reflow | Enables single-pass lead-free reflow assembly without moisture-related popcorning, reducing manufacturing yield risk. |
| Low incremental surge resistance | Minimizes voltage overshoot during fast-rising transients (<1 ns rise time), improving protection fidelity for high-speed digital interfaces. |
Applications
| Industrial Power Supply Input Protection | Automotive Body Control Module (BCM) CAN Line Clamp |
|---|---|
|
Use Scenario: 24 V DC input stage of programmable logic controller (PLC) exposed to load dump and inductive kickback from solenoid drivers. IC Role / Device Role / Timing Role: Unidirectional TVS placed between +24 V rail and chassis ground to clamp transients before they reach upstream DC-DC converter ICs. Use Value: 29.2 V clamping voltage ensures protected buck controller (e.g., LM5017) stays within its 36 V abs max rating during 100 V/10 ms load dump events. |
Use Scenario: 12 V power rail feeding CAN transceiver (e.g., TJA1042) in vehicle door module subject to ISO 7637-2 Pulse 1/2a/5a. IC Role / Device Role / Timing Role: Standoff-rated TVS on VCC line to absorb coupled transients without disrupting CAN bus timing integrity or causing transceiver latch-up. Use Value: 1.0 µA leakage at 18 V prevents quiescent current increase in always-on BCM circuits, preserving battery life over 15-year service life. |
| Consumer Appliance Motor Drive Board | Telecom PoE Midspan Surge Interface |
|
Use Scenario: Brushless DC motor driver board in HVAC blower unit, where MOSFET bridge switching induces >100 V ringing on DC bus. IC Role / Device Role / Timing Role: TVS mounted directly across bulk capacitor terminals to clamp repetitive switching spikes before they propagate to gate drivers and MCU. Use Value: 20.5 A IPPM rating handles cumulative surge energy from daily motor startups, avoiding parametric shift after 100,000 cycles. |
Use Scenario: Secondary-side 48 V DC input of PoE-powered access point, exposed to induced surges from nearby AC mains wiring. IC Role / Device Role / Timing Role: Primary protection element on PSE output line, coordinated with secondary TVS and gas discharge tube for multi-stage Class B immunity. Use Value: 600 W PPPM supports coordination with upstream 5 kA GDT, enabling full IEC 61000-4-5 4 kV common-mode surge compliance without derating. |
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-E3/5B | Same electrical specs, but RoHS-compliant with brominated flame retardant (non-halogen-free); JEDEC MSL Level 1, 260 °C. | Acceptable for commercial-grade consumer products where halogen-free certification is not mandated (e.g., UL 62368-1 Annex Q). | Select when cost sensitivity outweighs halogen-free requirement and supply chain allows dual-sourcing between M3 and E3 variants. |
| SMAJ18A-M3 | Lower 400 W PPPM rating, 32.4 V VC at 12.5 A IPPM, SMA (DO-214AC) package (smaller 4.5 mm × 2.7 mm footprint). | Suitable for space-constrained designs with lower surge threat levels (e.g., IEC 61000-4-2 ESD only), but insufficient for IEC 61000-4-5 Level 3. | Choose only if board area is critical and surge test requirements are limited to ±8 kV contact ESD; verify clamping margin against protected IC's VDS(max). |
Compared with SMBJ18A-E3/5B, the M3 variant adds halogen-free compliance without sacrificing electrical performance; versus SMAJ18A-M3, the SMBJ18A-M3/5B delivers 50 % higher surge power handling and lower clamping voltage - essential for protecting 30 V-rated power management ICs in harsh environments.
Availability
SMBJ18A-M3/5B is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, consumer appliance motor controls, and telecom PoE interfaces requiring stable component supply with halogen-free compliance and AEC-Q101-ready qualification path.
Supply support for SMBJ18A-M3/5B 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, thermal performance, and automotive qualification.
The SMBJ series was engineered for high-energy transient suppression in compact surface-mount formats, targeting industrial automation, automotive subsystems, and infrastructure equipment where failure modes must be mitigated without increasing PCB area.
FAQ
What is the maximum clamping voltage of SMBJ18A-M3/5B under a 10/1000 µs surge?
The SMBJ18A-M3/5B has a maximum clamping voltage (VC) of 29.2 V at 20.5 A peak pulse current (IPPM) under the standardized 10/1000 µs waveform. This value is measured per ANSI/IEEE C62.35 and ensures protected downstream components - such as 30 V-rated MOSFETs or DC-DC controllers - remain within their absolute maximum voltage ratings during surge events. The SMBJ18A-M3/5B achieves this with low incremental surge resistance and fast avalanche response.
Does SMBJ18A-M3/5B meet automotive qualification standards?
The SMBJ18A-M3/5B itself is commercial-grade with halogen-free RoHS compliance (M3 suffix), but Vishay offers AEC-Q101-qualified versions under ordering codes SMBJ18AHM3_X (e.g., SMBJ18AHM3_B/I). While SMBJ18A-M3/5B is not AEC-Q101 certified, its construction - including glass-passivated junction, 150 °C TJ max, and MSL Level 1 - aligns with foundational automotive reliability requirements. For production automotive use, specify the HM3_X variant; SMBJ18A-M3/5B is suited for industrial and high-reliability consumer applications.
How does the M3 suffix differ from E3 in SMBJ18A-M3/5B?
The M3 suffix in SMBJ18A-M3/5B denotes halogen-free, RoHS-compliant construction using non-brominated flame retardants in the molding compound, whereas E3 indicates RoHS compliance with traditional brominated materials. Both share identical electrical specifications, SMB package dimensions, and MSL Level 1 rating. The SMBJ18A-M3/5B meets IPC-1752A material declaration requirements and is preferred for markets enforcing halogen restrictions (e.g., certain EU industrial directives and Japanese Eco Mark programs).
What is the thermal resistance of SMBJ18A-M3/5B, and how does it affect layout?
The SMBJ18A-M3/5B 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 means a 5.0 W steady-state power dissipation (PD) raises junction temperature by 500 °C above ambient - which exceeds its 150 °C limit. Therefore, SMBJ18A-M3/5B is intended for transient-only operation; PCB layout must prioritize short, wide traces to ground and avoid thermal isolation. Continuous power dissipation must remain negligible.
Can SMBJ18A-M3/5B be used in bidirectional protection circuits?
No - SMBJ18A-M3/5B is a unidirectional TVS diode, identified by its cathode band marking and specified breakdown behavior only in reverse bias. For bidirectional transient suppression (e.g., AC lines or differential data buses), Vishay specifies parts with "CA" suffixes like SMBJ18CA. Using SMBJ18A-M3/5B in bidirectional configurations risks forward conduction during negative half-cycles, potentially damaging the diode or failing to protect. Always match polarity: SMBJ18A-M3/5B for DC rails with defined ground reference; SMBJ18CA for symmetrical or AC-coupled paths.
SMBJ18A-M3/5B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AA, SMB
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMBJ)
SMBJ18A-M3/5B FAQ
1.How can I place an order for SMBJ18A-M3/5B through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ18A-M3/5B 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 SMBJ18A-M3/5B reliable?
The price and inventory of SMBJ18A-M3/5B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ18A-M3/5B is usually 5 days.
3.What payment methods are accepted for SMBJ18A-M3/5B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ18A-M3/5B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ18A-M3/5B?
SMBJ18A-M3/5B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ18A-M3/5B 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 SMBJ18A-M3/5B?
For technical support, including SMBJ18A-M3/5B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ18A-M3/5B requirements.
6.How does Aetrix verify that SMBJ18A-M3/5B is sourced from the original manufacturer or authorized distributors?
All SMBJ18A-M3/5B 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 SMBJ18A-M3/5B meets industry standards.
7.What is the process for return or replacement of SMBJ18A-M3/5B?
All SMBJ18A-M3/5B units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ18A-M3/5B, 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 SMBJ18A-M3/5B part is unused and in its original packaging.
Return procedure for SMBJ18A-M3/5B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ18A-M3/5B Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
-
D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
-
D5V0L1B2WS-7
Diodes Incorporated
Tech Hub
Comparator circuit design covering voltage thresholds, input limits, open-collector outputs, LM393 wiring, op-amp differences, hysteresis, timing, window detection and practical fault diagnosis.
Schmitt triggers use separate rising and falling thresholds to stabilize slow or noisy signals. This guide covers hysteresis, 74HC14 and 74HCT14 selection, comparator calculations, RC oscillators and p…
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
