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Vishay General Semiconductor - Diodes Division SMBJ78CAHM3/I
- Part No.:
- SMBJ78CAHM3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ78CAHM3/I.pdf
- Description:
- TVS DIODE 78VWM 126VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:8,103
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Product details
Overview
SMBJ78CAHM3/I from Vishay General Semiconductor is a bidirectional surface-mount Transient Voltage Suppressor (TVS) diode in SMB (DO-214AA) package, designed for robust overvoltage protection of sensitive electronics. It features a 78 V standoff voltage (VWM), 86.7–95.8 V breakdown voltage (VBR) at 1 mA, 600 W peak pulse power (10/1000 µs), clamping voltage of 126 V at 4.8 A IPPM, and operates across –55 °C to +150 °C junction temperature range - deployed in industrial sensor signal lines and power supply rails.
For engineers reviewing the SMBJ78CAHM3/I datasheet, SMBJ78CAHM3/I pinout, SMBJ78CAHM3/I application, or SMBJ78CAHM3/I equivalent, this page delivers verified electrical specs, bidirectional clamping behavior, thermal resistance (RθJA = 100 °C/W), AEC-Q101 qualification status, and halogen-free RoHS-compliant construction per Vishay Document 88392 (Rev. 09-Jan-2024).
Technical Context
This bidirectional TVS diode uses a glass-passivated silicon junction to achieve fast response time (<1 ns), low incremental surge resistance, and stable clamping under repetitive transients. Its symmetrical I-V characteristics enable identical protection in both polarities without polarity marking on the case.
Designed for mounting on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads, it delivers 600 W peak pulse power with 0.01% duty cycle and derates linearly above 25 °C ambient per Fig. 2. Thermal resistance junction-to-ambient is 100 °C/W, and junction-to-lead is 20 °C/W - critical for layout-dependent power handling in compact PCBs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM (Stand-off Voltage) | 78 V - maximum continuous reverse voltage before significant leakage; defines safe operating margin below clamping threshold |
| VBR (Breakdown Voltage) | 86.7–95.8 V at 1 mA - guaranteed conduction onset range; ensures predictable turn-on during transients |
| VC (Clamping Voltage) | 126 V at IPPM = 4.8 A - peak voltage seen by protected circuit during 10/1000 µs surge; limits stress on downstream ICs |
| PPPM (Peak Pulse Power) | 600 W - maximum transient energy absorption capability with 10/1000 µs waveform; defines surge survivability |
| ID (Reverse Leakage) | 1.0 µA max at VWM - ultra-low standby current preserves system efficiency and avoids false triggering |
| TJ max | +150 °C - enables operation in high-temperature environments such as automotive engine bays or industrial enclosures |
| Package | SMB (DO-214AA) - surface-mount footprint (5.21 mm × 4.06 mm × 2.20 mm) compatible with automated placement and reflow |
Pinout & Package
Package: SMB (DO-214AA), bidirectional configuration - no polarity marking; symmetrical terminals function identically as anode/cathode depending on transient polarity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Terminal 1 | Anode / Cathode (bidirectional) | Either terminal serves as anode or cathode depending on applied transient polarity; no fixed polarity |
| Terminal 2 | Anode / Cathode (bidirectional) | Complementary terminal; forms symmetrical clamping path with Terminal 1 for AC or dual-polarity DC protection |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC lines, differential signals, or ungrounded DC rails without polarity concerns |
| 600 W peak pulse power (10/1000 µs) | Withstands high-energy surges common in industrial motor drives and relay switching environments |
| AEC-Q101 qualified (HM3 suffix) | Validated for automotive-grade reliability including temperature cycling, humidity bias, and mechanical shock |
| Halogen-free & RoHS-compliant | Meets environmental compliance requirements for consumer, industrial, and automotive end equipment |
| MSL Level 1 (260 °C peak reflow) | Supports standard lead-free SMT assembly without moisture sensitivity limitations or baking requirements |
Applications
| Industrial Sensor Signal Protection | Automotive Body Control Module (BCM) Power Input |
|---|---|
Use Scenario: Protecting 4–20 mA analog sensor outputs from ESD and inductive kickback in factory automation systems. IC Role / Device Role / Timing Role: Bidirectional TVS placed across signal line and ground to clamp ±2 kV ESD (IEC 61000-4-2) and 100 V/µs transients. Use Value: Prevents latch-up or damage to precision ADCs and op-amps while maintaining <1 µA leakage at 24 V nominal rail. |
Use Scenario: Safeguarding 12 V supply input of BCM microcontrollers against load dump (ISO 7637-2 Pulse 5a) and jump-start surges. IC Role / Device Role / Timing Role: Primary clamping device parallel to bulk capacitor; absorbs up to 600 W transient energy within 1000 µs. Use Value: Limits voltage to ≤126 V during 35 V/100 ms load dump events, preserving MCU and CAN transceiver integrity. |
| Telecom Line Interface Protection | Consumer Appliance Motor Drive Board |
Use Scenario: Shielding RS-485 transceivers on telecom base station backhaul links from lightning-induced surges. IC Role / Device Role / Timing Role: Differential-mode TVS across A/B bus lines; symmetric clamping maintains common-mode rejection. Use Value: Clamps 4 kV surge (IEC 61000-4-5) to <130 V while adding <1 pF capacitance - no data rate degradation at 10 Mbps. |
Use Scenario: Suppressing commutation spikes from brushed DC motors in washing machine control boards. IC Role / Device Role / Timing Role: Mounted across motor terminals to divert inductive energy away from H-bridge MOSFETs. Use Value: Withstands 100 A IFSM surge (8.3 ms half-sine), preventing MOSFET avalanche failure during abrupt motor stop/start. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ78CAHE3/I | Same electrical specs and SMB package; RoHS-compliant but not halogen-free; lacks AEC-Q101 qualification | Suitable for commercial/industrial use where automotive reliability validation is not required | Select when halogen-free content or automotive qualification is unnecessary and cost optimization is prioritized |
| SMAJ78CAHM3 | Lower 400 W PPPM rating; SMA (DO-214AC) package (smaller footprint, higher RθJA = 140 °C/W) | Acceptable for lower-energy transients or space-constrained layouts where thermal margin allows | Choose only if board area is critical and surge threat level is ≤400 W; verify thermal performance with layout |
Compared with SMBJ78CAHM3/I, SMBJ78CAHE3/I offers identical protection performance without halogen-free or automotive qualification, while SMAJ78CAHM3 trades 33% lower surge capacity and reduced thermal robustness for smaller size - making SMBJ78CAHM3/I the optimal choice for high-reliability, high-energy industrial and automotive applications.
Availability
SMBJ78CAHM3/I is available at Aetrix Electronics and suitable for industrial sensor interfaces, automotive body control modules, telecom line protection, and appliance motor drive circuits requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for SMBJ78CAHM3/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, TVS devices, and optoelectronics with emphasis on reliability, efficiency, and application-specific performance.
The SMBJ series was engineered for high-power transient suppression in harsh environments - targeting automotive, industrial, and telecom systems where robustness, AEC-Q101 compliance, and precise clamping are mandatory.
FAQ
What does the "CA" suffix indicate in SMBJ78CAHM3/I?
The "CA" suffix denotes a bidirectional configuration - meaning SMBJ78CAHM3/I provides symmetrical clamping for both positive and negative transients without polarity dependence. Unlike unidirectional variants (e.g., SMBJ78A), it has no cathode band marking and functions identically across either terminal orientation, making it ideal for AC-coupled or floating signal lines.
Is SMBJ78CAHM3/I suitable for automotive applications?
Yes - SMBJ78CAHM3/I carries the HM3 suffix, confirming it is halogen-free, RoHS-compliant, and AEC-Q101 qualified. This certification validates its performance under automotive-grade stress tests including temperature cycling, humidity bias, and mechanical shock - enabling use in body control modules, infotainment power supplies, and sensor interfaces per ISO/TS 16949 requirements.
What is the clamping voltage of SMBJ78CAHM3/I at rated surge current?
The clamping voltage (VC) of SMBJ78CAHM3/I is 126 V measured at its peak pulse current (IPPM) of 4.8 A under the standardized 10/1000 µs waveform. This value represents the maximum voltage imposed on the protected circuit during worst-case surge conditions and is confirmed in Vishay's datasheet Document 88392, Table on page 2.
How does SMBJ78CAHM3/I differ from SMBJ78A?
SMBJ78CAHM3/I is bidirectional with symmetrical VBR and VC characteristics in both polarities, whereas SMBJ78A is unidirectional with a cathode band marking and forward voltage drop (~3.5 V at 50 A). SMBJ78A supports forward conduction and higher IFSM (100 A), while SMBJ78CAHM3/I is optimized for AC or dual-rail protection where polarity reversal occurs.
What PCB layout guidance applies to SMBJ78CAHM3/I for optimal thermal performance?
For optimal thermal performance, SMBJ78CAHM3/I must be mounted on minimum 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal as specified in Vishay's datasheet. Reducing pad size increases RθJA beyond the rated 100 °C/W, risking thermal runaway during repetitive surges - especially critical in enclosed industrial enclosures or automotive under-hood applications.
SMBJ78CAHM3/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:
- Discontinued at Digi-Key
- 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/I FAQ
1.How can I place an order for SMBJ78CAHM3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ78CAHM3/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/I reliable?
The price and inventory of SMBJ78CAHM3/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/I is usually 5 days.
3.What payment methods are accepted for SMBJ78CAHM3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ78CAHM3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ78CAHM3/I?
SMBJ78CAHM3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ78CAHM3/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/I?
For technical support, including SMBJ78CAHM3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ78CAHM3/I requirements.
6.How does Aetrix verify that SMBJ78CAHM3/I is sourced from the original manufacturer or authorized distributors?
All SMBJ78CAHM3/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/I meets industry standards.
7.What is the process for return or replacement of SMBJ78CAHM3/I?
All SMBJ78CAHM3/I units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ78CAHM3/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/I part is unused and in its original packaging.
Return procedure for SMBJ78CAHM3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ78CAHM3/I Tags
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