My Inquiry
My Account
Vishay General Semiconductor - Diodes Division SMAJ78CAHE3_A/H
- Part No.:
- SMAJ78CAHE3_A/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ78CAHE3_A/H.pdf
- Description:
- TVS DIODE 78VWM 126VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:6,484
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMAJ78CAHE3_A/H from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in SMA (DO-214AC) 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 3.2 A peak pulse current, and 400 W peak pulse power rating (10/1000 μs waveform) - suitable for protecting automotive sensor interfaces and industrial I/O circuits against ESD and load dump.
For engineers reviewing the SMAJ78CAHE3_A/H datasheet, SMAJ78CAHE3_A/H pinout, SMAJ78CAHE3_A/H application, or SMAJ78CAHE3_A/H equivalent, key selection criteria include bidirectional clamping capability, AEC-Q101 qualification, 150 °C junction temperature rating, low incremental surge resistance, and compatibility with automated SMT placement on 0.2" × 0.2" copper pads.
Technical Context
This bidirectional TVS operates symmetrically across both polarities, delivering identical clamping performance in forward and reverse directions. Its glass-passivated junction ensures stable breakdown behavior and fast response time (<1 ns), while the SMA package supports high thermal dissipation via low RθJL (30 °C/W) and meets MSL level 1 reflow requirements (260 °C peak).
The device is rated for 400 W peak pulse power up to 78 V, derating to 300 W above 78 V per Fig. 2 of the datasheet. It sustains repetitive surges at 0.01 % duty cycle and exhibits a typical temperature coefficient of VBR at +0.106 %/°C - critical for thermal stability in under-hood automotive environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78 V - maximum continuous reverse stand-off voltage before significant leakage; defines operating margin below clamping threshold |
| VBR min/max | 86.7 V / 95.8 V at 1 mA - guaranteed breakdown range ensuring consistent turn-on during transients |
| VC @ IPPM | 126 V at 3.2 A - clamping voltage limiting downstream IC stress during 10/1000 μs surge events |
| PPPM | 400 W (≤78 V), 300 W (>78 V) - peak pulse power handling capacity with defined waveform and derating |
| ID @ VWM | 1.0 μA - ultra-low reverse leakage preserving signal integrity and system quiescent current |
| TJ max | +150 °C - enables operation in harsh automotive and industrial ambient conditions |
| AEC-Q101 | Qualified - validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, bidirectional configuration with no polarity marking. Dimensions: 4.50 mm × 2.79 mm × 2.29 mm (L × W × H); terminals are matte tin-plated, solderable per J-STD-002 and JESD 22-B102.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Terminal 1 (cathode band side not applicable) | One side of symmetrical junction; functions identically as cathode in reverse bias due to bidirectional design |
| Cathode | Terminal 2 (cathode band side not applicable) | Other side of symmetrical junction; no polarity marking required; both terminals behave identically |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Identical VBR and VC in both directions - eliminates need for polarity-aware layout in differential or AC-coupled lines |
| AEC-Q101 qualification | Validated for automotive applications including engine control units and ADAS sensor interfaces |
| 400 W peak pulse power | Robust protection against ISO 7637-2 Pulse 1/2a/5a and IEC 61000-4-5 surges without derating below 78 V |
| MSL Level 1 | Compatible with standard lead-free reflow profiles up to 260 °C peak - no moisture sensitivity handling required |
| Glass passivated junction | Stable VBR over lifetime and temperature; low leakage and high reliability in humid or high-bias environments |
Applications
| Automotive Sensor Protection | Industrial PLC I/O Protection |
|---|---|
Use Scenario: Protecting CAN/LIN bus transceivers and analog sensor inputs (e.g., pressure, temperature) from load dump and ESD in vehicle ECUs. IC Role / Device Role / Timing Role: Bidirectional voltage clamp placed directly at connector interface to limit transient energy entering signal conditioning circuitry. Use Value: Maintains signal fidelity under ±126 V clamping while supporting AEC-Q101 compliance for functional safety-critical subsystems. |
Use Scenario: Safeguarding 24 V DC digital input modules in programmable logic controllers against field-wiring transients and relay coil flyback. IC Role / Device Role / Timing Role: Primary front-end transient suppressor on isolated input channels, coordinated with optocoupler or digital isolator. Use Value: Enables robust 24 V system operation with <1.0 μA leakage at full VWM, minimizing false triggering in high-impedance sensing nodes. |
| Telecom Power Line Protection | Consumer Appliance Motor Control |
Use Scenario: Clamping induced surges on PoE-powered Ethernet ports and auxiliary 12–48 V DC rails in base station equipment. IC Role / Device Role / Timing Role: Secondary-level TVS after primary MOV/GDT stages, providing precise low-clamp protection for sensitive PHY ICs. Use Value: Delivers 126 V clamping at 3.2 A with <1 ns response - faster than most varistors - preserving data integrity during lightning-induced surges. |
Use Scenario: Suppressing commutation spikes from brushed DC motors and solenoids in washing machines, HVAC actuators, and power tools. IC Role / Device Role / Timing Role: Parallel-mounted across motor terminals or driver MOSFET drains to absorb inductive kickback energy. Use Value: Handles 40 A non-repetitive forward surge (IFSM) and 300–400 W pulse power - sufficient for repeated motor start-stop cycles. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ78CA-E3/61 | Same electrical specs and SMA package; RoHS-compliant commercial grade without AEC-Q101 qualification | Lacks automotive qualification; suitable for industrial/commercial designs where AEC-Q101 is not mandated | Select when cost-sensitive non-automotive applications require identical clamping but not automotive reliability validation |
| SMLJ78CAHE3_A/H | Higher 1500 W peak pulse power rating (same VWM/VBR/VC), larger SMC (DO-214AB) package | Used where higher surge energy absorption is needed (e.g., 48 V battery systems, heavy-duty industrial drives) | Choose when system-level surge tests exceed 400 W - requires PCB layout change due to larger SMC footprint |
Compared with SMAJ78CAHE3_A/H, SMAJ78CA-E3/61 offers identical protection performance without automotive qualification, while SMLJ78CAHE3_A/H provides 3.75× higher pulse power in a physically larger package - enabling tiered surge robustness without redesigning clamping topology.
Availability
SMAJ78CAHE3_A/H is available at Aetrix Electronics and suitable for automotive sensor interfaces, industrial PLC I/O modules, telecom power line protection, and consumer appliance motor control requiring stable component supply and AEC-Q101 assurance.
Supply support for SMAJ78CAHE3_A/H 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 and application-specific optimization.
The SMAJ series is engineered for high-speed transient suppression in space-constrained, high-reliability applications - particularly targeting automotive, industrial, and telecom systems needing repeatable clamping and AEC-Q101 validation.
FAQ
What is the clamping voltage of SMAJ78CAHE3_A/H at its rated peak pulse current?
The SMAJ78CAHE3_A/H has a maximum clamping voltage (VC) of 126 V at its specified peak pulse current (IPPM) of 3.2 A, measured using the standardized 10/1000 μs double-exponential waveform. This value ensures downstream components see limited overvoltage during surge events, and it is guaranteed across the full operating temperature range per the Vishay datasheet revision 09-Jan-2024. The SMAJ78CAHE3_A/H maintains this clamping performance bidirectionally.
Is SMAJ78CAHE3_A/H qualified for automotive applications?
Yes, SMAJ78CAHE3_A/H is AEC-Q101 qualified, as confirmed by Vishay's ordering code suffix "HE3" and documentation in the SMAJ5.0A–SMAJ188CA datasheet (Document Number: 88390). This qualification covers stress tests including temperature cycling, high-temperature reverse bias, and ESD, making the SMAJ78CAHE3_A/H suitable for use in engine control units, body electronics, and ADAS sensor modules where automotive-grade reliability is mandatory.
What does the "CA" suffix indicate in SMAJ78CAHE3_A/H?
The "CA" suffix in SMAJ78CAHE3_A/H denotes a bidirectional configuration - meaning the device provides symmetrical transient suppression in both forward and reverse directions, with identical breakdown and clamping characteristics. Unlike unidirectional variants (e.g., SMAJ78A), the SMAJ78CAHE3_A/H has no polarity marking and is used where AC signals, differential buses, or undefined voltage polarity require equal protection regardless of surge direction.
What is the maximum operating junction temperature for SMAJ78CAHE3_A/H?
The maximum operating junction temperature (TJ max) for SMAJ78CAHE3_A/H is +150 °C, as specified in the Vishay datasheet under "Maximum Ratings." This rating allows reliable operation in under-hood automotive environments and high-ambient industrial settings. Derating of peak pulse power begins above TA = 25 °C per Figure 2, and thermal design must account for RθJA = 120 °C/W and RθJL = 30 °C/W to maintain safe junction temperatures during sustained surge events.
How does the SMAJ78CAHE3_A/H differ from the SMAJ78A variant?
The SMAJ78CAHE3_A/H is bidirectional, whereas SMAJ78A is unidirectional - resulting in different electrical behavior: SMAJ78CAHE3_A/H clamps equally in both polarities with no cathode marking, while SMAJ78A has a defined cathode band and only clamps in reverse bias. Additionally, SMAJ78CAHE3_A/H uses the HE3 suffix indicating AEC-Q101 qualification and RoHS compliance, whereas SMAJ78A may carry E3/M3 suffixes without automotive validation. Their VWM, VBR, and VC values are matched within tolerance, but circuit implementation differs fundamentally.
SMAJ78CAHE3_A/H Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AC, SMA
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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):
- 3.2A
- Power - Peak Pulse:
- 400W
- 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-214AC (SMA)
SMAJ78CAHE3_A/H FAQ
1.How can I place an order for SMAJ78CAHE3_A/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ78CAHE3_A/H 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 SMAJ78CAHE3_A/H reliable?
The price and inventory of SMAJ78CAHE3_A/H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ78CAHE3_A/H is usually 5 days.
3.What payment methods are accepted for SMAJ78CAHE3_A/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ78CAHE3_A/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ78CAHE3_A/H?
SMAJ78CAHE3_A/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ78CAHE3_A/H 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 SMAJ78CAHE3_A/H?
For technical support, including SMAJ78CAHE3_A/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ78CAHE3_A/H requirements.
6.How does Aetrix verify that SMAJ78CAHE3_A/H is sourced from the original manufacturer or authorized distributors?
All SMAJ78CAHE3_A/H 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 SMAJ78CAHE3_A/H meets industry standards.
7.What is the process for return or replacement of SMAJ78CAHE3_A/H?
All SMAJ78CAHE3_A/H units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ78CAHE3_A/H, 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 SMAJ78CAHE3_A/H part is unused and in its original packaging.
Return procedure for SMAJ78CAHE3_A/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ78CAHE3_A/H 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 …
