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Vishay General Semiconductor - Diodes Division SMBJ78CAHM3_A/I
- Part No.:
- SMBJ78CAHM3_A/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ78CAHM3_A/I.pdf
- Description:
- TVS DIODE 78VWM 126VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:5,858
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Product details
Overview
SMBJ78CAHM3_A/I from Vishay General Semiconductor is a bidirectional 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 78 V stand-off voltage (VWM), 86.7–95.8 V breakdown voltage (VBR) at 1 mA, 126 V maximum clamping voltage (VC) at 4.8 A peak pulse current, and 600 W peak pulse power rating with 10/1000 µs waveform - used to protect MOSFETs, sensor interfaces, and industrial I/O circuits against ESD and inductive switching surges.
For engineers reviewing the SMBJ78CAHM3_A/I datasheet, SMBJ78CAHM3_A/I pinout, SMBJ78CAHM3_A/I application, or SMBJ78CAHM3_A/I equivalent, this device is evaluated for bidirectional surge protection in automotive-grade commercial designs where halogen-free, AEC-Q101-qualified TVS performance and MSL Level 1 reflow compatibility are required.
Technical Context
This bidirectional TVS operates symmetrically across both polarities, delivering consistent clamping behavior without polarity dependence. Its glass-passivated junction ensures stable leakage (<1.0 µA at VWM) and fast response time (<1.0 ns), while the low incremental surge resistance supports effective energy diversion during transient events.
The device is rated for 150 °C maximum junction temperature and exhibits a typical thermal resistance of 100 °C/W (junction-to-ambient) on standard 0.2" × 0.2" copper pads. Its halogen-free, RoHS-compliant HM3 suffix confirms compliance with JESD201 Class 2 whisker resistance and JEDEC MSL Level 1 handling up to 260 °C peak reflow.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78 V - maximum continuous reverse operating voltage before clamping initiates; defines safe operating margin for 72–80 V nominal supply rails. |
| VBR min/max | 86.7 V / 95.8 V at 1 mA - guaranteed breakdown range ensures predictable turn-on across production lots and temperature. |
| VC @ IPPM | 126 V at 4.8 A - clamping voltage under 600 W 10/1000 µs surge; limits downstream voltage stress to ≤126 V during worst-case transients. |
| PPPM | 600 W - peak pulse power handling capability per single 10/1000 µs waveform; supports repetitive surges at 0.01% duty cycle. |
| ID @ VWM | <1.0 µA - ultra-low reverse leakage preserves signal integrity and minimizes standby power loss in high-impedance circuits. |
| TJ max | +150 °C - enables reliable operation in under-hood automotive, industrial motor drives, and enclosed power supplies. |
| Package | SMB (DO-214AA) - standardized surface-mount outline with 5.59 mm × 4.06 mm footprint and 2.20 mm height; compatible with automated pick-and-place. |
Pinout & Package
Package: SMB (DO-214AA), bidirectional configuration - no polarity marking; symmetrical terminals function as interchangeable anode/cathode pair.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Terminal 1) | Transient current entry point (either polarity) | Accepts surge current during positive or negative voltage excursions; connects to protected line (e.g., CAN_H or RS-485 A). |
| Cathode (Terminal 2) | Transient current return path (either polarity) | Completes low-impedance path to ground or reference rail during clamping; requires low-inductance layout to maintain VC performance. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC-coupled or differential lines (e.g., RS-485, CAN, USB D+/D−) without polarity concerns. |
| 600 W peak pulse power | Withstands IEC 61000-4-5 Level 4 surges (4 kV, 2 Ω source) when properly laid out, reducing need for cascaded protection stages. |
| Halogen-free & AEC-Q101 qualified | HM3 suffix certifies compliance for automotive electronics including body control modules and infotainment power rails. |
| MSL Level 1 moisture sensitivity | Allows unlimited floor life and standard reflow profiling up to 260 °C peak, eliminating bake requirements prior to assembly. |
| Glass-passivated junction | Ensures long-term stability of VBR and leakage over temperature and lifetime, critical for industrial field-deployed equipment. |
Applications
| Automotive Body Control Module | Industrial RS-485 Communication Line |
|---|---|
|
Use Scenario: Protecting LIN/CAN bus nodes from load dump and alternator ripple in door module ECUs. IC Role / Device Role / Timing Role: Bidirectional voltage clamp placed between bus line and chassis ground to limit transients to <126 V. Use Value: Prevents latch-up or permanent damage to transceivers such as TJA1042T/3, enabling >100,000-cycle reliability in 12 V vehicle systems. |
Use Scenario: Shielding RS-485 transceivers (e.g., MAX1487) from EFT bursts and cable discharge events in factory automation networks. IC Role / Device Role / Timing Role: Low-capacitance (≈150 pF) bidirectional TVS shunting differential surges between A/B lines and ground. Use Value: Maintains signal integrity up to 10 Mbps by limiting clamping overshoot to ≤126 V without adding timing skew or jitter. |
| Consumer Appliance Motor Drive | Telecom Power Input Stage |
|
Use Scenario: Suppressing inductive kickback from brushed DC motors in washing machine control boards. IC Role / Device Role / Timing Role: Parallel-connected TVS across H-bridge outputs to clamp flyback spikes before they reach gate drivers. Use Value: Eliminates need for snubbers or Zener stacks; reduces BOM count while sustaining 600 W surge absorption per event. |
Use Scenario: Safeguarding AC/DC front-end rectifiers and PFC controllers against lightning-induced surges on telecom power inputs. IC Role / Device Role / Timing Role: Primary-level TVS placed after fuse but before bulk capacitor to absorb line-to-ground transients. Use Value: Complies with ITU-T K.20/21 immunity requirements by clamping 10/700 µs surges to <126 V with sub-ns response. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ78CAHE3_A/I | RoHS-compliant but not halogen-free; lacks JESD201 Class 2 whisker resistance certification. | Suitable for non-automotive commercial use where halogen content is unrestricted. | Select when cost sensitivity outweighs automotive qualification or halogen-free requirements. |
| SMCJ78CAHM3_A/I | Same electrical specs but SMC (DO-214AB) package - 7.11 mm × 6.22 mm footprint, 2.39 mm height, 1500 W PPPM. | Used where higher surge margin or board-level robustness is prioritized over space-constrained layouts. | Choose when PCB real estate allows larger package and system-level surge testing exceeds 600 W. |
Compared with SMBJ78CAHM3_A/I, the HE3 variant trades halogen-free construction for lower unit cost in non-automotive settings, while the SMCJ78CAHM3_A/I delivers 2.5× higher surge capacity in a physically larger package - enabling design flexibility across cost, space, and ruggedness trade-offs.
Availability
SMBJ78CAHM3_A/I is available at Aetrix Electronics and suitable for automotive body electronics, industrial communication interfaces, consumer appliance motor controls, and telecom power input protection requiring stable component supply and full traceability.
Supply support for SMBJ78CAHM3_A/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, MOSFETs, and protection devices with emphasis on reliability, efficiency, and application-specific optimization.
The SMBJ series targets surface-mount transient suppression in space-constrained, high-reliability environments - engineered for rapid response, repeatable clamping, and seamless integration into automotive, industrial, and communications infrastructure.
FAQ
What does the "CA" suffix indicate in SMBJ78CAHM3_A/I?
The "CA" suffix denotes a bidirectional configuration - meaning SMBJ78CAHM3_A/I provides symmetrical clamping for both positive and negative voltage transients without polarity dependency. Unlike unidirectional "A" variants, it has no cathode band marking and functions identically regardless of terminal orientation, making it ideal for AC signal lines and differential buses like CAN or RS-485 where polarity reversal may occur.
Is SMBJ78CAHM3_A/I qualified for automotive applications?
Yes, SMBJ78CAHM3_A/I is AEC-Q101 qualified, as confirmed by its HM3 suffix and documentation in Vishay's 88392 datasheet. This qualification covers stress testing for temperature cycling, humidity bias, mechanical shock, and high-temperature operating life - validating its suitability for under-hood and cabin-mounted automotive electronics including body control units and infotainment power domains.
What is the maximum clamping voltage of SMBJ78CAHM3_A/I and at what current is it specified?
The maximum clamping voltage (VC) of SMBJ78CAHM3_A/I is 126 V, measured at a peak pulse current (IPPM) of 4.8 A using the standardized 10/1000 µs double-exponential waveform. This value represents the upper limit of voltage seen by downstream circuitry during a 600 W transient event and is guaranteed across the full operating temperature range per Vishay's datasheet specifications.
How does the HM3 suffix differ from the HE3 suffix in SMBJ78CAHM3_A/I?
The HM3 suffix in SMBJ78CAHM3_A/I indicates halogen-free, RoHS-compliant, and AEC-Q101-qualified construction with JESD201 Class 2 whisker resistance, whereas HE3 is RoHS-compliant and AEC-Q101-qualified but not halogen-free. Both meet MSL Level 1 and share identical electrical parameters, but HM3 satisfies stricter environmental mandates for automotive Tier 1 suppliers and green manufacturing programs.
Can SMBJ78CAHM3_A/I be used in place of a unidirectional SMBJ78AHM3_A/I?
No - SMBJ78CAHM3_A/I is bidirectional and lacks polarity marking, while SMBJ78AHM3_A/I is unidirectional with a cathode band and only clamps in reverse bias. Substituting them requires circuit redesign: the CA version protects AC or floating lines, whereas the A version must be oriented correctly relative to DC polarity. Using SMBJ78CAHM3_A/I in a unidirectional application adds unnecessary cost and may degrade leakage performance due to dual-junction structure.
SMBJ78CAHM3_A/I 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:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 78V
- Voltage - Breakdown (Min):
- 86.7V
- Voltage - Clamping (Max) @ Ipp:
- 126V
- Current - Peak Pulse (10/1000µs):
- 4.8A
- 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)
SMBJ78CAHM3_A/I FAQ
1.How can I place an order for SMBJ78CAHM3_A/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ78CAHM3_A/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 SMBJ78CAHM3_A/I reliable?
The price and inventory of SMBJ78CAHM3_A/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ78CAHM3_A/I is usually 5 days.
3.What payment methods are accepted for SMBJ78CAHM3_A/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ78CAHM3_A/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ78CAHM3_A/I?
SMBJ78CAHM3_A/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ78CAHM3_A/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 SMBJ78CAHM3_A/I?
For technical support, including SMBJ78CAHM3_A/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ78CAHM3_A/I requirements.
6.How does Aetrix verify that SMBJ78CAHM3_A/I is sourced from the original manufacturer or authorized distributors?
All SMBJ78CAHM3_A/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 SMBJ78CAHM3_A/I meets industry standards.
7.What is the process for return or replacement of SMBJ78CAHM3_A/I?
All SMBJ78CAHM3_A/I units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ78CAHM3_A/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 SMBJ78CAHM3_A/I part is unused and in its original packaging.
Return procedure for SMBJ78CAHM3_A/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ78CAHM3_A/I Tags
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DESD3V3E1BL-7B
Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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