My Inquiry
My Account
Vishay General Semiconductor - Diodes Division SMCJ78AHE3/57T
- Part No.:
- SMCJ78AHE3/57T
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ78AHE3/57T.pdf
- Description:
- TVS DIODE 78VWM 126VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:5,769
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMCJ78AHE3/57T from Vishay General Semiconductor is a unidirectional transient voltage suppressor (TVS) diode in SMC (DO-214AB) package, designed for robust overvoltage protection of DC power rails and signal lines. It features a 78 V stand-off voltage (VWM), 86.7–95.8 V breakdown voltage (VBR) at 1 mA, 1500 W peak pulse power (10/1000 μs), 126 V maximum clamping voltage at 11.9 A IPPM, and AEC-Q101 qualification for automotive use.
For engineers reviewing the SMCJ78AHE3/57T datasheet, SMCJ78AHE3/57T pinout, SMCJ78AHE3/57T application, or SMCJ78AHE3/57T equivalent, key selection criteria include clamping performance under 10/1000 μs surge, thermal resistance (RθJA = 75 °C/W), unidirectional polarity marking, RoHS-compliant matte tin plating, and compatibility with automated SMT placement on 8.0 mm × 8.0 mm copper pads.
Technical Context
The SMCJ78AHE3/57T operates as a unidirectional avalanche diode, conducting only when reverse voltage exceeds its breakdown threshold to clamp transients. Its glass-passivated junction ensures stable VBR tolerance (±5%) and low incremental surge resistance, enabling fast response (<1 ns) to ESD and lightning-induced surges.
It is rated for -55 °C to +150 °C operating junction temperature, meets MSL Level 1 per J-STD-020 (peak reflow 260 °C), and delivers 126 V clamping at 11.9 A peak pulse current - critical for protecting 72–80 V industrial power supplies and automotive 78 V battery systems against ISO 7637-2 Pulse 1/2a/5a events.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78 V - Maximum continuous reverse operating voltage before clamping begins; sets safe margin above nominal 72 V rail. |
| VBR (min/max) | 86.7 V / 95.8 V at IT = 1 mA - Confirmed avalanche onset range; defines minimum trigger threshold under production tolerance. |
| VC @ IPPM | 126 V at 11.9 A (10/1000 μs) - Clamped voltage seen by protected circuit during worst-case surge; limits stress on downstream ICs. |
| PPPM | 1500 W - Peak transient energy absorption capability; supports high-energy surges without failure. |
| ID @ VWM | 1.0 μA - Reverse leakage at stand-off voltage; negligible power loss and minimal impact on high-impedance sensor biasing. |
| TJ max. | +150 °C - Enables operation in under-hood automotive environments and industrial enclosures with elevated ambient temperatures. |
| RθJA | 75 °C/W - Thermal resistance from junction to ambient on standard 8.0 mm × 8.0 mm pads; informs derating above 25 °C ambient. |
Pinout & Package
Package: SMC (DO-214AB), surface-mount, molded plastic case with UL 94 V-0 flammability rating; cathode indicated by band on body; matte tin-plated leads compliant with J-STD-002 and JESD 22-B102.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential side (e.g., ground or return path); conducts during forward surge (e.g., reverse-battery event). |
| Cathode | Reverse-biased clamping terminal | Connected to protected line (e.g., 78 V rail); avalanche conduction initiates here when voltage exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing - required for engine control, ADAS, and infotainment modules. |
| Glass passivated junction | Ensures stable VBR over lifetime and temperature; eliminates parameter drift due to moisture ingress or metallization degradation. |
| Low incremental surge resistance | Minimizes voltage overshoot during fast-rising transients (e.g., ISO 16750-2 load dump), improving clamping fidelity. |
| MSL Level 1 rating | Supports single-reflow assembly at 260 °C peak without popcorn cracking or delamination - compatible with standard SMT lines. |
| 1500 W 10/1000 μs rating | Withstands repeated high-energy surges common in industrial motor drives and telecom power systems without parametric shift. |
Applications
| Automotive Power Rail Protection | Industrial DC Power Supply Clamping |
|---|---|
|
Use Scenario: Protecting 72–80 V battery-fed ECUs (e.g., HVAC controllers, body control modules) against ISO 7637-2 Pulse 5a (load dump) and Pulse 1 (inductive switching). IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery input and DC-DC converter input stage to clamp transients before they reach regulation circuitry. Use Value: Limits clamped voltage to 126 V, well below typical 150 V input rating of buck controllers, preventing latch-up or gate oxide damage. |
Use Scenario: Safeguarding 78 V output of industrial programmable logic controller (PLC) power supplies against field-wiring transients and relay coil flyback. IC Role / Device Role / Timing Role: Primary overvoltage clamp on regulated DC bus, mounted directly at supply output connector to minimize inductance. Use Value: Absorbs 1500 W surges without degradation, maintaining system uptime in factory-floor environments with frequent EMI exposure. |
| Telecom 48–72 V Backup System | Sensor Signal Line Transient Suppression |
|
Use Scenario: Securing backup battery interface in telecom base station power systems where 78 V float voltage is used for extended runtime. IC Role / Device Role / Timing Role: Standby TVS across battery input terminals to suppress surges during hot-swap insertion or grid fault recovery. Use Value: 1.0 μA leakage at 78 V prevents measurable self-discharge over months, preserving battery charge integrity. |
Use Scenario: Protecting analog inputs of 78 V-powered current sensors (e.g., shunt-based motor phase monitors) from ESD and cable discharge events. IC Role / Device Role / Timing Role: Low-capacitance unidirectional clamp on sensor output line, referenced to local ground. Use Value: Clamps sub-100 ns ESD pulses to <126 V while adding <10 pF capacitance - no signal integrity impact on kHz-range current waveforms. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ78A | Same 78 V VWM, 1500 W PPPM, but SMC package variant with RθJA = 80 °C/W and no AEC-Q101 qualification. | Not approved for automotive under-hood use; suitable for commercial/industrial power supplies only. | Select if AEC-Q101 is not required and cost sensitivity outweighs thermal margin. |
| ON Semiconductor 1.5SMC78A | Identical electrical specs (VWM = 78 V, VC = 126 V, PPPM = 1500 W), same SMC package, but rated only to TJ = 125 °C and lacks AEC-Q101 validation. | Limited to ambient temperatures ≤85 °C; unsuitable for engine bay or high-power industrial enclosures. | Choose for non-automotive designs where junction temperature remains below 125 °C and automotive qualification is unnecessary. |
Compared with Littelfuse SMAJ78A and ON Semi 1.5SMC78A, the SMCJ78AHE3/57T provides superior thermal robustness (TJ max = 150 °C vs. 125 °C) and certified automotive reliability - essential for designs requiring long-term field stability in harsh environments.
Availability
SMCJ78AHE3/57T is available at Aetrix Electronics and suitable for automotive ECU protection, industrial PLC power rails, telecom backup systems, and sensor interface circuits requiring stable component supply with full traceability and long-lifecycle support.
Supply support for SMCJ78AHE3/57T 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, precision, and application-specific optimization.
The SMCJ series was developed for high-energy transient suppression in automotive, industrial, and telecom infrastructure - prioritizing clamping accuracy, surge endurance, and AEC-Q101 compliance from wafer to final test.
FAQ
What is the clamping voltage of the SMCJ78AHE3/57T at its rated peak pulse current?
The SMCJ78AHE3/57T clamps to a maximum of 126 V at its specified peak pulse current of 11.9 A under the standard 10/1000 μs waveform. This value is measured per JEDEC test conditions and represents the upper limit of voltage imposed on the protected circuit during worst-case surge events - critical for ensuring downstream components remain within their absolute maximum ratings.
Is the SMCJ78AHE3/57T suitable for automotive applications?
Yes, the SMCJ78AHE3/57T is AEC-Q101 qualified and explicitly designated for automotive use via the "HE3" suffix. It has passed stress tests including high-temperature reverse bias, temperature cycling, and ESD per AEC standards, making it appropriate for engine control units, ADAS power domains, and body electronics where reliability under thermal and electrical stress is mandatory.
What does the "/57T" suffix indicate in SMCJ78AHE3/57T?
The "/57T" suffix denotes packaging: 7-inch diameter plastic tape and reel, with a base quantity of 850 units per reel. This format is optimized for high-speed SMT placement equipment and aligns with industry-standard feeding mechanisms - confirmed in Vishay's ordering information table on page 3 of document 88394.
How does the SMCJ78AHE3/57T differ from bidirectional variants like SMCJ78CA?
The SMCJ78AHE3/57T is unidirectional and features a cathode band for polarity identification, enabling asymmetric protection of positive-only rails. In contrast, SMCJ78CA is bidirectional with no polarity marking and symmetrical clamping in both directions - used where AC-coupled signals or dual-polarity transients require suppression without regard to DC bias direction.
What is the thermal resistance of the SMCJ78AHE3/57T, and how does it affect layout design?
The SMCJ78AHE3/57T has a typical junction-to-ambient thermal resistance (RθJA) of 75 °C/W when mounted on 8.0 mm × 8.0 mm copper pads per terminal. This value requires PCB layout with adequate copper area and thermal vias to maintain junction temperature below 150 °C - especially important in high-ambient environments such as automotive under-hood or industrial control cabinets.
SMCJ78AHE3/57T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AB, SMC
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- 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):
- 11.9A
- Power - Peak Pulse:
- 1500W (1.5kW)
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AB (SMCJ)
SMCJ78AHE3/57T FAQ
1.How can I place an order for SMCJ78AHE3/57T through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ78AHE3/57T 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 SMCJ78AHE3/57T reliable?
The price and inventory of SMCJ78AHE3/57T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ78AHE3/57T is usually 5 days.
3.What payment methods are accepted for SMCJ78AHE3/57T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ78AHE3/57T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ78AHE3/57T?
SMCJ78AHE3/57T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ78AHE3/57T 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 SMCJ78AHE3/57T?
For technical support, including SMCJ78AHE3/57T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ78AHE3/57T requirements.
6.How does Aetrix verify that SMCJ78AHE3/57T is sourced from the original manufacturer or authorized distributors?
All SMCJ78AHE3/57T 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 SMCJ78AHE3/57T meets industry standards.
7.What is the process for return or replacement of SMCJ78AHE3/57T?
All SMCJ78AHE3/57T units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ78AHE3/57T, 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 SMCJ78AHE3/57T part is unused and in its original packaging.
Return procedure for SMCJ78AHE3/57T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMCJ78AHE3/57T 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 …
