My Inquiry
My Account
Vishay General Semiconductor - Diodes Division SMBJ78A-M3/52
;;2.jpg)
- Part No.:
- SMBJ78A-M3/52
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ78A-M3/52.pdf
- Description:
- TVS DIODE 78VWM 126VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:4,544
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMBJ78A-M3/52 from Vishay General Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in SMB (DO-214AA) package, designed to protect sensitive electronics against ESD, lightning-induced surges, and inductive switching transients. 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.
For engineers reviewing the SMBJ78A-M3/52 datasheet, SMBJ78A-M3/52 pinout, SMBJ78A-M3/52 application, or SMBJ78A-M3/52 equivalent, key selection criteria include clamping performance under 4.8 A surge, thermal resistance (RθJA = 100 °C/W), halogen-free RoHS compliance (M3 suffix), and compatibility with automated SMT placement on 5.0 mm × 5.0 mm copper pads.
Technical Context
This TVS diode operates as a unidirectional clamping device with cathode-band polarity marking, leveraging a glass-passivated silicon junction for low leakage (<1.0 µA at VWM) and fast response time (<1.0 ns). Its 150 °C maximum junction temperature and MSL Level 1 moisture sensitivity support reflow soldering up to 260 °C peak.
The SMBJ78A-M3/52 delivers stable clamping across repetitive 0.01% duty cycle surges, with incremental surge resistance optimized for low VC – VBR differential (≤39.3 V), and meets UL 497B recognition (QVGQ2) for telecom and industrial protector classification.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78 V - Maximum continuous reverse operating voltage before clamping begins; defines safe signal line operating margin. |
| VBR (min/max) | 86.7 V / 95.8 V at 1 mA - Confirmed breakdown threshold range; ensures reliable turn-on above normal operating voltage. |
| VC @ IPPM | 126 V at 4.8 A - Clamped voltage during 10/1000 µs surge; determines protected circuit's maximum transient exposure. |
| PPPM | 600 W - Peak pulse power handling capability; supports robust protection against IEC 61000-4-5 Level 4 surges. |
| IPPM | 4.8 A - Peak pulse current corresponding to VC; used to size PCB trace width and verify system-level surge path. |
| RθJA | 100 °C/W - Junction-to-ambient thermal resistance; requires ≥5.0 mm × 5.0 mm copper pad per terminal for rated power dissipation. |
| TJ max. | +150 °C - Maximum junction temperature; enables operation in industrial ambient environments up to +85 °C with derating. |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, halogen-free, RoHS-compliant (M3 suffix), matte tin-plated leads, MSL Level 1, 0.106 g unit weight. Cathode indicated by band marking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference node | Connected to ground or common return path; forms clamping loop with cathode during transient events. |
| Cathode | Protected line input | Connected to signal/power line requiring protection; conducts surge current to anode when VAK exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| 600 W peak pulse power (10/1000 µs) | Enables single-device protection against IEC 61000-4-5 4 kV/2 Ω surge test without external series impedance. |
| 126 V clamping voltage at 4.8 A | Limits transient overvoltage on 72–80 V DC bus lines (e.g., PoE++, industrial 75 V rails) to safe levels for downstream MOSFETs or controllers. |
| Glass-passivated junction | Ensures <1.0 µA reverse leakage at 78 V, minimizing standby power loss in always-on sensor or telemetry circuits. |
| MSL Level 1, 260 °C peak reflow | Supports standard lead-free SMT assembly without pre-baking or special handling, reducing manufacturing overhead. |
| Halogen-free, RoHS-compliant (M3) | Fulfills environmental compliance requirements for EU, China RoHS, and automotive supply chains without material substitution risk. |
Applications
| Industrial Motor Drives | Telecom Power Feeds |
|---|---|
|
Use Scenario: Protection of gate drivers and current-sense amplifiers in 72 V DC-fed servo inverters exposed to IGBT switching noise and load dump. IC Role / Device Role / Timing Role: Unidirectional TVS clamping element placed across DC bus inputs and isolated signal lines. Use Value: Limits transient overshoot to ≤126 V during 4.8 A surges, preventing latch-up or oxide breakdown in 100 V-rated SiC gate drivers. |
Use Scenario: Surge suppression on -48 V DC power feeds in LTE base station remote radio units (RRUs) subjected to lightning-induced common-mode transients. IC Role / Device Role / Timing Role: Primary line-side TVS on feed input, coordinated with upstream gas discharge tube (GDT) for staged protection. Use Value: Clamps residual surges after GDT conduction to safe levels for -48 V DC-DC converters, meeting GR-1089-CORE Level 4 immunity. |
| Automotive Body Control Modules | Industrial PLC Analog Inputs |
|
Use Scenario: Input protection for LIN bus transceivers and power window motor H-bridge controllers in 12 V systems with load-dump transients. IC Role / Device Role / Timing Role: Secondary TVS on 12 V supply rail and LIN data line, following primary AEC-Q101-qualified front-end protection. Use Value: Provides cost-effective backup clamping with 126 V VC, ensuring microcontroller I/O remains below absolute maximum ratings during ISO 16750-2 pulses. |
Use Scenario: Overvoltage safeguard for 4–20 mA current-loop analog inputs in factory automation sensors exposed to field wiring faults and ESD. IC Role / Device Role / Timing Role: Unidirectional shunt protector between input terminals and local ground, sized for 78 V loop supply headroom. Use Value: Maintains <1.0 µA leakage at 78 V, avoiding measurement error in high-impedance receiver circuits while clamping 4.8 A transients. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ78A-E3/52 | Same electrical specs; RoHS-compliant but not halogen-free (E3 vs. M3). | Acceptable where halogen-free requirement is not mandated (e.g., non-automotive commercial equipment). | Select E3 for cost-sensitive, non-automotive designs with standard RoHS compliance. |
| SMBJ78CA-M3/52 | Bidirectional variant; symmetric VBR (86.7–95.8 V) in both polarities; same VC and PPPM. | Required for AC-coupled or dual-polarity signal lines (e.g., RS-485, CAN FD) where reverse polarity surges occur. | Choose CA version only when protecting bidirectional interfaces; unidirectional SMBJ78A-M3/52 is optimal for DC rails. |
Compared with SMBJ78A-E3/52, the M3 suffix adds halogen-free compliance critical for automotive and green procurement programs; compared with SMBJ78CA-M3/52, the unidirectional configuration provides lower leakage and avoids unnecessary bidirectional conduction in DC applications.
Availability
SMBJ78A-M3/52 is available at Aetrix Electronics and suitable for industrial motor drives, telecom power feeds, automotive body control modules, and PLC analog inputs requiring stable component supply with halogen-free compliance and MSL Level 1 manufacturability.
Supply support for SMBJ78A-M3/52 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, power efficiency, and application-specific performance.
The SMBJ series was developed for high-energy transient suppression in space-constrained surface-mount applications across industrial, telecom, and automotive sectors, balancing clamping precision, surge robustness, and manufacturability.
FAQ
What is the maximum clamping voltage of SMBJ78A-M3/52 under a 10/1000 µs surge?
The SMBJ78A-M3/52 has a maximum clamping voltage (VC) of 126 V when subjected to its rated peak pulse current of 4.8 A with a 10/1000 µs waveform. This value is measured per Figure 1 in Vishay document 88392 and defines the upper voltage limit imposed on protected circuitry during transient events. The SMBJ78A-M3/52 maintains this clamping performance across its specified operating temperature range.
Is SMBJ78A-M3/52 suitable for automotive applications?
The SMBJ78A-M3/52 is halogen-free and RoHS-compliant but is not AEC-Q101 qualified. For automotive use, Vishay offers the AEC-Q101-qualified variant SMBJ78A-HM3_X (e.g., SMBJ78A-HM3_A). The SMBJ78A-M3/52 is appropriate for non-safety-critical automotive subsystems where qualification is not mandated, such as infotainment power rails or lighting control modules outside ASIL zones.
What does the "M3" suffix indicate in SMBJ78A-M3/52?
The "M3" suffix in SMBJ78A-M3/52 denotes halogen-free, RoHS-compliant construction with matte tin-plated leads meeting JESD 201 Class 2 whisker resistance. It distinguishes the part from the "E3" (RoHS-compliant, non-halogen-free) and "HM3" (AEC-Q101 qualified + halogen-free) variants. The SMBJ78A-M3/52 is intended for commercial and industrial applications requiring green material compliance without automotive qualification.
How is the polarity marked on SMBJ78A-M3/52?
The SMBJ78A-M3/52 uses a cathode band marking on the package body to identify the cathode terminal, consistent with standard diode polarity convention. The banded end connects to the protected line (e.g., 78 V rail), while the unmarked end connects to ground or return. This marking is visible on the SMB (DO-214AA) case per Vishay mechanical drawing in document 88392.
What PCB pad layout is required for SMBJ78A-M3/52 to achieve full 600 W pulse rating?
To achieve the full 600 W peak pulse power rating, the SMBJ78A-M3/52 must be mounted on minimum 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal, as specified in Vishay document 88392. Smaller pads reduce thermal dissipation and require derating of IPPM and PPPM per Figure 2. The SMBJ78A-M3/52 thermal resistance (RθJA = 100 °C/W) assumes this pad layout.
SMBJ78A-M3/52 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):
- 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:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMBJ)
SMBJ78A-M3/52 FAQ
1.How can I place an order for SMBJ78A-M3/52 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ78A-M3/52 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 SMBJ78A-M3/52 reliable?
The price and inventory of SMBJ78A-M3/52 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ78A-M3/52 is usually 5 days.
3.What payment methods are accepted for SMBJ78A-M3/52?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ78A-M3/52 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ78A-M3/52?
SMBJ78A-M3/52 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ78A-M3/52 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 SMBJ78A-M3/52?
For technical support, including SMBJ78A-M3/52 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ78A-M3/52 requirements.
6.How does Aetrix verify that SMBJ78A-M3/52 is sourced from the original manufacturer or authorized distributors?
All SMBJ78A-M3/52 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 SMBJ78A-M3/52 meets industry standards.
7.What is the process for return or replacement of SMBJ78A-M3/52?
All SMBJ78A-M3/52 units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ78A-M3/52, 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 SMBJ78A-M3/52 part is unused and in its original packaging.
Return procedure for SMBJ78A-M3/52:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ78A-M3/52 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 …
