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Microchip Technology SMAJ78AE3/TR13
- Part No.:
- SMAJ78AE3/TR13
- Manufacturer:
- Microchip Technology
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ78AE3/TR13.pdf
- Description:
- TVS DIODE 78VWM 126VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:6,700
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Product details
Overview
SMAJ78AE3/TR13 from Microsemi is a unidirectional surface-mount Transient Voltage Suppressor (TVS) designed for primary overvoltage protection of DC power rails and signal lines. It features a 78 V standoff voltage (VWM), 86.7 V minimum breakdown voltage (VBR), 139 V maximum clamping voltage (VC) at 3.6 A peak pulse current, and 500 W peak pulse power rating per 10/1000 µs waveform - deployed in telecom power supplies and industrial I/O interfaces.
For engineers reviewing the SMAJ78AE3/TR13 datasheet, SMAJ78AE3/TR13 pinout, SMAJ78AE3/TR13 application, or SMAJ78AE3/TR13 equivalent, key selection criteria include clamping performance under IEC61000-4-5 secondary lightning surge (42 Ω source), low standby leakage (<1 µA @ 78 V), RoHS-compliant matte-tin plating, and compatibility with automated SMT assembly on FR4 PCBs using standard DO-214AC footprint.
Technical Context
This TVS operates as a silicon avalanche diode with unidirectional polarity (cathode-banded), optimized for fast transient response (<100 ps theoretical turn-on) and low thermal resistance (15 °C/W junction-to-lead). Its design targets suppression of ESD (IEC61000-4-2), EFT (IEC61000-4-4), and induced surges in 24–48 V DC systems.
Rated for -65 °C to +150 °C operating temperature and 0.01% impulse repetition rate, it delivers stable clamping across ambient conditions when mounted per recommended pad layout (JEDEC DO-214AC variant with extended lead width). The e3/TR13 suffix confirms RoHS compliance and tape-and-reel packaging (750 pcs/reel, 12 mm tape).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78 V - Maximum continuous reverse working voltage before conduction; sets upper limit for protected circuit's normal operating rail. |
| VBR min @ IBR | 86.7 V @ 1 mA - Minimum voltage at which avalanche breakdown begins; ensures reliable triggering above system transients. |
| VC @ IPP | 139 V @ 3.6 A - Clamped voltage during 10/1000 µs surge; defines worst-case stress on downstream ICs. |
| PPP | 500 W - Peak pulse power handling capability; validates robustness against IEC61000-4-5 Class 3 (42 Ω) surges. |
| ID @ VWM | <1 µA - Reverse leakage current at rated standoff; minimizes quiescent power loss in battery-powered systems. |
| Package | DO-214AC (SMA) - Standard surface-mount outline with wide leads for thermal dissipation and mechanical reliability in reflow soldering. |
Pinout & Package
DO-214AC (SMA) package: void-free thermosetting epoxy body (UL94V-0), C-bend leads with RoHS-compliant annealed matte-tin plating, cathode indicated by band. Weight: 0.064 g. Moisture sensitivity level: Level 1 (no dry pack required).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Surge return path / ground reference | Connected to system ground or low-impedance return plane; carries full surge current during clamping. |
| Cathode | Protected line input / high-side connection | Connected to the line being protected (e.g., +24 V rail); voltage referenced to anode during transient events. |
Key Features
| Feature | Design Value |
|---|---|
| 500 W peak pulse power | Enables single-device protection against IEC61000-4-5 secondary lightning surges up to Class 3 (42 Ω source impedance) without derating. |
| <100 ps theoretical response time | Clamps ESD events (IEC61000-4-2 ±8 kV contact) before sensitive logic or analog circuitry sustains damage. |
| RoHS-compliant "e3" finish | Matte-tin plating meets JEDEC J-STD-020B and supports lead-free reflow profiles up to 260 °C for 10 s. |
| 15 °C/W junction-to-lead thermal resistance | Allows sustained 5 W steady-state dissipation at 75 °C lead temperature - critical for high-duty-cycle industrial environments. |
Applications
| Industrial PLC I/O Protection | Telecom DC Power Input |
|---|---|
Use Scenario: 24 V DC inputs on programmable logic controller modules exposed to inductive load switching and field wiring surges. IC Role / Device Role / Timing Role: Unidirectional TVS placed between input terminal and ground to clamp positive-going transients before reaching input conditioning circuitry. Use Value: Limits voltage to ≤139 V during 3.6 A surges, preventing latch-up or gate oxide damage in upstream protection ICs and microcontrollers. |
Use Scenario: Primary overvoltage protection on +48 V telecom power distribution boards subject to lightning-induced coupling. IC Role / Device Role / Timing Role: Standoff-rated TVS on power entry point, coordinated with upstream fuses and downstream DC-DC converters. Use Value: Withstands 500 W surges per IEC61000-4-5 (42 Ω source), ensuring system-level immunity without requiring parallel devices. |
| Automotive Body Control Module | Medical Equipment Sensor Interface |
Use Scenario: 12–24 V supply lines in body control units subjected to load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Fast-response TVS on main power rail to suppress slow-rising (100 ms) load dump and fast-rising (5 ns) ESD events. Use Value: Low leakage (<1 µA) avoids battery drain; 150 °C max operating temperature supports under-hood placement. |
Use Scenario: Analog front-end protection for isolated patient-connected sensors operating from low-noise 5–12 V rails. IC Role / Device Role / Timing Role: Signal-line TVS on differential sensor inputs to prevent ESD-induced offset drift or ADC saturation. Use Value: 139 V clamping preserves signal integrity while maintaining sub-1 µA leakage to avoid baseline shift in precision amplifiers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ78AHE3/TR13 | Same electrical specs but with enhanced screening (avionics-grade: 10× temp cycling, HTRB, surge testing). | Required for aerospace/defense systems demanding MIL-PRF-19500 JANTX-level reliability. | Select only if qualification testing (e.g., MIL-STD-750 Method 1082) is mandated; otherwise, SMAJ78AE3/TR13 suffices for commercial/industrial use. |
| SMBJ78A-E3/52 | Higher 600 W PPP, same VWM/VC, but SMB (DO-214AA) package - 2.5 mm wider body, higher thermal mass. | Better suited for high-repetition-rate surges or elevated ambient temperatures (>100 °C). | Choose when board space allows larger footprint and thermal performance exceeds SMAJ78AE3/TR13's 15 °C/W junction-to-lead limit. |
Compared with SMAJ78AE3/TR13, SMAJ78AHE3/TR13 adds avionics screening without altering clamping behavior, while SMBJ78A-E3/52 trades compact DO-214AC size for higher surge margin and thermal robustness in constrained thermal environments.
Availability
SMAJ78AE3/TR13 is available at Aetrix Electronics and suitable for industrial PLC I/O protection, telecom DC power input, and automotive body control module designs requiring stable component supply, RoHS compliance, and verified IEC61000-4-5 surge immunity.
Supply support for SMAJ78AE3/TR13 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
Microsemi (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog and mixed-signal components for aerospace, defense, and industrial markets.
The SMAJ series was developed specifically for surface-mount transient suppression in space-constrained, high-surge environments - emphasizing fast response, repeatable clamping, and robust thermal performance in DO-214AC packaging.
FAQ
What is the clamping voltage of SMAJ78AE3/TR13 under a 10/1000 µs surge?
The SMAJ78AE3/TR13 has a maximum clamping voltage (VC) of 139 V at 3.6 A peak pulse current (IPP) for a 10/1000 µs waveform. This value is measured per Figure 2 in the official Microsemi datasheet MSC0270A and defines the upper voltage limit imposed on protected circuitry during standardized surge events.
Is SMAJ78AE3/TR13 unidirectional or bidirectional?
SMAJ78AE3/TR13 is a unidirectional TVS diode, indicated by the absence of "C" or "CA" in its part number suffix. It conducts only in reverse bias (anode to cathode) during overvoltage events and features a cathode band for polarity identification - unlike bidirectional variants such as SMAJ78CAE3/TR13.
Does SMAJ78AE3/TR13 meet IEC61000-4-5 requirements?
Yes, SMAJ78AE3/TR13 is rated for secondary lightning protection per IEC61000-4-5 with 42 Ω source impedance up to Class 3 (VWM ≤ 100 V), confirmed by its 500 W peak pulse power rating and 139 V clamping voltage. It also complies with IEC61000-4-2 (ESD) and IEC61000-4-4 (EFT) standards as specified in the Microsemi datasheet.
What is the maximum steady-state power dissipation for SMAJ78AE3/TR13?
SMAJ78AE3/TR13 dissipates up to 5 W continuously when lead temperature (TL) is maintained at 75 °C, or 1.56 W at 25 °C ambient (TA) on a standard FR4 PCB with 1 oz copper and recommended footprint. This is defined in the "Steady-State Power Dissipation" section of the Microsemi datasheet MSC0270A.
What does the "TR13" suffix indicate in SMAJ78AE3/TR13?
The "TR13" suffix denotes tape-and-reel packaging per EIA-481-1-A standard: 12 mm carrier tape, 2500 units per 13-inch reel. This format supports automated pick-and-place assembly and is distinct from the "TR" (750/reel) or bulk options - all confirmed in the Mechanical and Packaging section of the SMAJ datasheet.
SMAJ78AE3/TR13 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Package/Case:
- DO-214AC, SMA
- Series:
- -
- 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):
- 4A
- Power - Peak Pulse:
- 500W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ78AE3/TR13 FAQ
1.How can I place an order for SMAJ78AE3/TR13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ78AE3/TR13 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 SMAJ78AE3/TR13 reliable?
The price and inventory of SMAJ78AE3/TR13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ78AE3/TR13 is usually 5 days.
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SMAJ78AE3/TR13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ78AE3/TR13 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 SMAJ78AE3/TR13?
For technical support, including SMAJ78AE3/TR13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ78AE3/TR13 requirements.
6.How does Aetrix verify that SMAJ78AE3/TR13 is sourced from the original manufacturer or authorized distributors?
All SMAJ78AE3/TR13 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 SMAJ78AE3/TR13 meets industry standards.
7.What is the process for return or replacement of SMAJ78AE3/TR13?
All SMAJ78AE3/TR13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ78AE3/TR13, 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 SMAJ78AE3/TR13 part is unused and in its original packaging.
Return procedure for SMAJ78AE3/TR13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ78AE3/TR13 Tags
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