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Microchip Technology SMAJ78CAE3/TR13
- Part No.:
- SMAJ78CAE3/TR13
- Manufacturer:
- Microchip Technology
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ78CAE3/TR13.pdf
- Description:
- TVS DIODE 78VWM 126VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:3,308
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Product details
Overview
SMAJ78CAE3/TR13 from Microsemi is a bidirectional surface-mount transient voltage suppressor (TVS) diode designed for robust ESD, EFT, and secondary lightning surge protection in DC power rails and signal lines. It features a 78 V reverse 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.
For engineers reviewing the SMAJ78CAE3/TR13 datasheet, SMAJ78CAE3/TR13 pinout, SMAJ78CAE3/TR13 application, or SMAJ78CAE3/TR13 equivalent, key selection criteria include bidirectional clamping capability, RoHS-compliant matte-tin plating, DO-214AC package compatibility, IEC61000-4-2/4-4/4-5 compliance, and suitability for industrial power supply input stages, telecom interface protection, and automotive body electronics.
Technical Context
The SMAJ78CAE3/TR13 operates as a symmetrical avalanche diode with identical forward and reverse breakdown characteristics due to its bidirectional construction (CA suffix). Its sub-5 ns response time enables suppression of fast transients including ESD events (±15 kV contact per IEC61000-4-2) and electrical fast transients (4 kV per IEC61000-4-4).
It delivers 500 W peak pulse power handling at 25 °C with derating to zero at 150 °C junction temperature, supported by a thermal resistance of 15 °C/W (junction-to-lead) and 80 °C/W (junction-to-ambient on FR4 with recommended footprint). The device exhibits ≤1 μA standby leakage current at 78 V and is rated for operation from –65 °C to +150 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78 V - Maximum continuous DC or RMS voltage the device blocks without conduction. |
| VBR min | 86.7 V @ 1 mA - Minimum voltage at which avalanche breakdown begins in either polarity. |
| VC max | 139 V @ 3.6 A - Maximum voltage seen across terminals during 10/1000 µs surge, limiting stress on downstream ICs. |
| PPP | 500 W - Peak transient power dissipation capability under standardized surge waveform. |
| IPP | 3.6 A - Peak current the device safely clamps at VC, derived from PPP/VC. |
| ID max | 1 μA @ VWM - Low leakage ensures minimal power loss and no false triggering in high-impedance circuits. |
| TJ range | –65 °C to +150 °C - Enables use in extended-temperature environments including under-hood automotive and industrial controls. |
Pinout & Package
Package: DO-214AC (SMA), surface-mount, void-free thermosetting epoxy case with matte-tin-plated C-bend leads; moisture sensitivity level (MSL) 1 - no dry pack required per IPC/JEDEC J-STD-020B.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode / Cathode (symmetrical) | Bidirectional avalanche junction | No polarity marking; identical clamping behavior in both directions - simplifies PCB layout and eliminates orientation errors. |
| Case / Body | Thermal path & mechanical anchor | Wide lead geometry provides low thermal resistance (15 °C/W) and robust solder joint reliability on FR4 boards. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC-coupled or floating signal lines without external polarity management. |
| 500 W peak pulse power | Supports IEC61000-4-5 Class 3 (42 Ω source) lightning surge immunity up to 1 kV open-circuit voltage. |
| RoHS-compliant "e3" finish | Matte-tin plating meets JEDEC J-STD-020B and ensures reliable solderability without lead-based alloys. |
| Sub-5 ns response time | Clamps ESD events before sensitive CMOS inputs reach destructive voltage thresholds - critical for USB, RS-485, and CAN interfaces. |
| DO-214AC footprint | Direct drop-in compatibility with industry-standard SMA land patterns, enabling reuse of existing PCB layouts. |
Applications
| Industrial Power Input Protection | Telecom Interface Surge Suppression |
|---|---|
Use Scenario: 24–48 V DC input stage of programmable logic controllers (PLCs) exposed to load dump and inductive switching transients. IC Role / Device Role / Timing Role: Primary overvoltage clamp placed upstream of DC-DC converters and microcontroller power rails. Use Value: Limits transient voltage to ≤139 V, preventing latch-up or gate oxide damage in downstream 5 V/3.3 V regulators and logic ICs. | Use Scenario: RS-485 data lines in outdoor base stations subjected to induced surges from nearby lightning strikes. IC Role / Device Role / Timing Role: Bidirectional TVS placed differential-mode across A/B bus lines, referenced to local ground. Use Value: Clamps ±1 kV IEC61000-4-5 surges within 5 ns while adding <1 pF capacitance per line - preserving signal integrity at 10 Mbps. |
| Automotive Body Control Module | Consumer Appliance Motor Drive Inputs |
Use Scenario: LIN bus or sensor supply lines in door modules operating in ambient temperatures from –40 °C to +125 °C. IC Role / Device Role / Timing Role: Secondary protection element after primary fuse, guarding against battery reverse connection and jump-start transients. Use Value: Withstands 100% temperature cycling (–55 °C to +125 °C) and maintains <1 μA leakage at 78 V - ensuring long-term reliability without calibration drift. | Use Scenario: Mains-connected AC motor control boards in washing machines, exposed to switching noise from triac dimmers and relay coils. IC Role / Device Role / Timing Role: Line-to-line and line-to-ground clamping on rectified DC bus feeding H-bridge drivers. Use Value: Absorbs 500 W repetitive surges without degradation, extending lifetime of MOSFET gate drivers and reducing field failure rates by >90% vs. unclamped designs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ78CA | Same VWM, VBR, VC; lower PPP = 600 W but SMB package (DO-214AA) has higher thermal resistance (25 °C/W). | Less effective in high-temperature or high-duty-cycle surge environments due to reduced thermal performance. | Select SMBJ78CA only if board space allows larger SMB footprint and thermal margin is verified. |
| SMCJ78CA | Same VWM, VBR, VC; higher PPP = 1500 W in SMC package (DO-214AB), but 3× larger footprint and 2× weight. | Over-specified for 500 W requirements; suitable only when legacy designs require backward-compatible surge headroom. | Choose SMCJ78CA only when system-level testing confirms need for >1000 W surge handling or MIL-STD-883 screening is mandated. |
Compared with SMBJ78CA and SMCJ78CA, the SMAJ78CAE3/TR13 delivers optimal balance of 500 W surge capacity, DO-214AC footprint compactness, and thermal efficiency - making it the preferred choice for space-constrained industrial and automotive PCBs requiring certified IEC61000-4-5 Class 3 immunity.
Availability
SMAJ78CAE3/TR13 is available at Aetrix Electronics and suitable for industrial PLCs, telecom base station interfaces, automotive body control modules, and consumer appliance motor drives requiring stable component supply and full traceability.
Supply support for SMAJ78CAE3/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, industrial, and communications markets.
The SMAJ series was engineered specifically for surface-mount transient suppression in harsh environments, emphasizing rapid response, repeatable clamping, and extended temperature operation - targeting applications where failure is not an option.
FAQ
What does the "CA" suffix indicate in SMAJ78CAE3/TR13?
The "CA" suffix denotes a bidirectional configuration - meaning the SMAJ78CAE3/TR13 provides symmetrical clamping in both polarities, with identical breakdown and clamping characteristics for positive and negative transients. This eliminates the need for polarity-aware placement and supports AC-coupled or floating signal lines, unlike unidirectional variants (e.g., SMAJ78A) that require correct anode/cathode orientation.
Is SMAJ78CAE3/TR13 compliant with IEC61000-4-5 for lightning surge protection?
Yes, the SMAJ78CAE3/TR13 is rated for secondary lightning surge protection per IEC61000-4-5 with 42 Ω source impedance up to Class 3 (1 kV open-circuit test voltage), and with 12 Ω source impedance up to Class 2. Its 139 V clamping voltage at 3.6 A ensures downstream circuitry remains within safe operating limits during standardized surge waveforms, provided layout follows Microsemi's recommended pad dimensions and grounding practices.
What is the thermal resistance of SMAJ78CAE3/TR13, and how does it affect PCB layout?
The SMAJ78CAE3/TR13 has a junction-to-lead thermal resistance of 15 °C/W and junction-to-ambient resistance of 80 °C/W when mounted on FR4 with 1 oz copper and Microsemi's recommended footprint. To maintain reliability under repeated surges, designers must ensure adequate copper pour area connected to both leads and avoid narrow traces - insufficient thermal relief can cause localized overheating and premature wear-out of the avalanche junction.
Does SMAJ78CAE3/TR13 require special handling for moisture sensitivity?
No - the SMAJ78CAE3/TR13 is rated at Moisture Sensitivity Level (MSL) 1 per IPC/JEDEC J-STD-020B, meaning it has unlimited floor life and requires no dry pack or baking prior to reflow soldering. Its void-free epoxy encapsulation and matte-tin plating ensure robust solderability at 260 °C for 10 seconds, supporting standard lead-free reflow profiles without popcorn cracking or delamination risks.
How does the "TR13" suffix impact packaging and ordering of SMAJ78CAE3/TR13?
The "TR13" suffix indicates tape-and-reel packaging per EIA-481-1-A standard: 12 mm carrier tape, 2500 units per 13-inch reel. This format is optimized for automated SMT placement and ensures consistent component orientation and feed reliability. Aetrix Electronics stocks SMAJ78CAE3/TR13 exclusively in this configuration, supporting high-volume production runs without manual handling or repackaging delays.
SMAJ78CAE3/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:
- -
- Bidirectional Channels:
- 1
- 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)
SMAJ78CAE3/TR13 FAQ
1.How can I place an order for SMAJ78CAE3/TR13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ78CAE3/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 SMAJ78CAE3/TR13 reliable?
The price and inventory of SMAJ78CAE3/TR13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ78CAE3/TR13 is usually 5 days.
3.What payment methods are accepted for SMAJ78CAE3/TR13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ78CAE3/TR13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ78CAE3/TR13?
SMAJ78CAE3/TR13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ78CAE3/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 SMAJ78CAE3/TR13?
For technical support, including SMAJ78CAE3/TR13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ78CAE3/TR13 requirements.
6.How does Aetrix verify that SMAJ78CAE3/TR13 is sourced from the original manufacturer or authorized distributors?
All SMAJ78CAE3/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 SMAJ78CAE3/TR13 meets industry standards.
7.What is the process for return or replacement of SMAJ78CAE3/TR13?
All SMAJ78CAE3/TR13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ78CAE3/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 SMAJ78CAE3/TR13 part is unused and in its original packaging.
Return procedure for SMAJ78CAE3/TR13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ78CAE3/TR13 Tags
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Diodes Incorporated
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Diodes Incorporated
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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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