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Microchip Technology SMAJ18AE3/TR13
- Part No.:
- SMAJ18AE3/TR13
- Manufacturer:
- Microchip Technology
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ18AE3/TR13.pdf
- Description:
- TVS DIODE 18VWM 29.2VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:4,924
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Product details
Overview
SMAJ18AE3/TR13 from Microsemi is a unidirectional surface-mount Transient Voltage Suppressor (TVS) designed for primary and secondary surge protection in DC power rails and signal lines. It features a 18 V reverse standoff voltage (VWM), 20.0 V minimum breakdown voltage (VBR), 29.2 V maximum clamping voltage (VC) at 17.2 A peak pulse current, and 500 W peak pulse power rating per 10/1000 µs waveform - deployed in industrial power supplies and automotive control modules.
For engineers reviewing the SMAJ18AE3/TR13 datasheet, SMAJ18AE3/TR13 pinout, SMAJ18AE3/TR13 application, or SMAJ18AE3/TR13 equivalent, key selection criteria include clamping performance under IEC61000-4-5 (42 Ω source), unidirectional polarity marking, RoHS-compliant matte-tin plating, and DO-214AC package compatibility with standard SMT reflow profiles.
Technical Context
This TVS diode operates as a fast-acting voltage-clamping device in series with sensitive downstream circuitry, conducting only when transient voltage exceeds its 20.0 V breakdown threshold. Its <100 ps theoretical response time enables effective suppression of ESD (IEC61000-4-2 Level 4) and EFT (IEC61000-4-4) events before damage occurs to CMOS or BiCMOS ICs.
The SMAJ18AE3/TR13 is rated for -65°C to +150°C operating temperature, exhibits 1 μA maximum standby leakage at 18 V, and delivers 500 W peak pulse power dissipation with thermal resistance of 15°C/W junction-to-lead - requiring no dry pack (Moisture Sensitivity Level 1) and supporting standard FR4 PCB mounting with recommended footprint per Microsemi's pad layout.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18 V - Maximum continuous DC or RMS voltage the device blocks without conduction; sets operating margin for 12–15 V nominal rails. |
| VBR min @ IBR | 20.0 V @ 1 mA - Minimum voltage at which avalanche breakdown begins; ensures reliable triggering above system operating voltage. |
| VC @ IPP | 29.2 V @ 17.2 A - Clamped voltage during 10/1000 µs surge; defines worst-case overvoltage seen by protected load. |
| PPP | 500 W - Peak pulse power handling capability; supports robust protection against lightning-induced surges per IEC61000-4-5 Class 3 (42 Ω source). |
| ID @ VWM | 1 μA max - Ultra-low leakage current at standoff voltage; prevents measurable power loss or bias shift in high-impedance circuits. |
| tclamp | <100 ps theoretical - Sub-nanosecond response enables protection of high-speed logic and microcontroller I/O pins against ESD. |
| Package | DO-214AC (SMA) - Standard surface-mount outline with C-bend leads; compatible with automated pick-and-place and reflow soldering (260°C/10 s). |
Pinout & Package
DO-214AC (SMA) package: void-free thermosetting epoxy body (UL94V-0), matte-tin plated C-bend leads, cathode indicated by band on body. Weight: 0.064 g. Moisture Sensitivity Level: 1 - no dry pack required.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side connection to protected line | Connected to circuit node requiring clamping (e.g., VIN rail); conducts surge current to ground when VANODE > VCATHODE + VBR. |
| Cathode | Reference terminal (marked with band) | Typically tied to system ground or low-impedance return path; establishes polarity and defines conduction direction for unidirectional operation. |
Key Features
| Feature | Design Value |
|---|---|
| 500 W peak pulse power | Enables single-device protection against severe transients including secondary lightning (IEC61000-4-5 Class 3) without derating or parallel devices. |
| RoHS-compliant "e3" suffix | Matte-tin plating meets JEDEC J-STD-020B and eliminates lead-based solder compatibility concerns in modern assembly lines. |
| Unidirectional configuration | Provides asymmetric clamping ideal for DC power rails where reverse voltage blocking is required and bidirectional noise immunity is unnecessary. |
| 100% temperature cycling screening option | Available with MA prefix for avionics-grade reliability (-55°C to +125°C, 10 cycles), though not included in SMAJ18AE3/TR13 base part number. |
| Tape-and-reel packaging (TR13) | 2500 units per 13-inch reel per EIA-481-1-A - optimized for high-volume SMT production with consistent feed and placement accuracy. |
Applications
| Industrial Power Supply Protection | Automotive Body Control Module |
|---|---|
Use Scenario: 24 V DC input stage of programmable logic controller (PLC) power supply exposed to load dump and inductive switching transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed between input rail and chassis ground to clamp surges before they reach DC-DC converter ICs and microcontrollers. Use Value: Limits transient overvoltage to ≤29.2 V, preventing latch-up or gate oxide damage in downstream MOSFET drivers and LDO regulators. |
Use Scenario: LIN bus transceiver power pin in door module subjected to battery reverse connection and jump-start spikes. IC Role / Device Role / Timing Role: Primary overvoltage clamp on VCC rail feeding LIN PHY IC, activated within <100 ps of surge onset. Use Value: Maintains safe operating voltage during 12 V system transients up to ±300 V/10/1000 µs, ensuring uninterrupted communication during vehicle cranking. |
| Telecom Remote Radio Unit | Medical Diagnostic Imaging Interface |
Use Scenario: 48 V PoE-powered remote radio unit (RRU) front-end exposed to induced surges from nearby lightning strikes. IC Role / Device Role / Timing Role: First-line TVS on DC input before DC-DC isolation stage, absorbing energy per IEC61000-4-5 Class 2 (42 Ω source). Use Value: Withstands 17.2 A peak pulse current while limiting clamped voltage to 29.2 V, preserving integrity of isolated gate drivers and ADC reference supplies. |
Use Scenario: Signal conditioning board for ultrasound probe interface, where analog front-end amplifiers require sub-μA leakage and fast transient rejection. IC Role / Device Role / Timing Role: Low-leakage (1 μA) unidirectional TVS on analog supply rail adjacent to precision op-amps and SAR ADCs. Use Value: Prevents ESD-induced offset drift or saturation in instrumentation amplifiers without introducing bias error or thermal noise from leakage current. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ18AHE3/TR13 | Same electrical specs but with enhanced reliability screening (H = high-reliability variant per MIL-PRF-19500 JANTX level). | Required for aerospace or military programs demanding extended temperature cycling and HTRB validation. | Select SMAJ18AHE3/TR13 only if qualification to MIL-PRF-19500 is mandated; otherwise SMAJ18AE3/TR13 satisfies commercial/industrial requirements. |
| SMBJ18A-E3/52 | Same VWM, VBR, VC, but lower 600 W PPP rating and SMB (DO-214AA) package - 20% smaller footprint, higher thermal resistance (20°C/W). | Better suited for space-constrained consumer electronics where 600 W margin suffices and thermal mass is limited. | Choose SMBJ18A-E3/52 only when board area is critical and peak surge energy remains within 600 W; SMAJ18AE3/TR13 offers superior thermal performance in industrial environments. |
Compared with SMAJ18AHE3/TR13, the SMAJ18AE3/TR13 omits military-grade screening but retains identical clamping behavior and RoHS compliance; versus SMBJ18A-E3/52, it trades slightly larger size for lower thermal resistance and proven robustness in high-energy surge environments.
Availability
SMAJ18AE3/TR13 is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, telecom remote radio units, and medical diagnostic imaging interfaces requiring stable component supply across long-lifecycle programs.
Supply support for SMAJ18AE3/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 engineered specifically for surface-mount transient suppression in harsh environments - delivering 500 W surge capability in the compact DO-214AC package while maintaining low leakage and nanosecond response for mission-critical systems.
FAQ
What is the clamping voltage of SMAJ18AE3/TR13 at its rated peak pulse current?
The SMAJ18AE3/TR13 has a maximum clamping voltage (VC) of 29.2 V at 17.2 A peak pulse current (IPP) under the standard 10/1000 µs waveform. This value is measured per Microsemi's test conditions and defines the upper voltage limit imposed on protected circuitry during surge events - critical for ensuring downstream ICs remain within absolute maximum ratings.
Is SMAJ18AE3/TR13 unidirectional or bidirectional?
SMAJ18AE3/TR13 is a unidirectional Transient Voltage Suppressor, indicated by the absence of "C" or "CA" in its part number suffix. It features a cathode band marking and conducts only when anode voltage exceeds cathode voltage by ≥20.0 V - making it appropriate for DC power rail protection where reverse polarity blocking is required.
Does SMAJ18AE3/TR13 comply with RoHS and what does the "e3" suffix signify?
Yes, SMAJ18AE3/TR13 is RoHS compliant, as confirmed by the "e3" suffix per Microsemi documentation. This denotes annealed matte-tin plating on leads, meeting JEDEC J-STD-020B and eliminating lead-based solder compatibility issues - verified for use in environmentally regulated commercial and industrial applications.
What is the maximum steady-state power dissipation of SMAJ18AE3/TR13 on a standard FR4 board?
When mounted on an FR4 PCB with 1 oz copper and Microsemi's recommended footprint, SMAJ18AE3/TR13 dissipates up to 1.56 W at 25°C ambient temperature (TA) or 5 W at 75°C lead temperature (TL). These values reflect thermal resistance of 80°C/W (junction-to-ambient) and 15°C/W (junction-to-lead), respectively - essential for thermal design validation.
Can SMAJ18AE3/TR13 be used for IEC61000-4-5 lightning surge protection?
Yes, SMAJ18AE3/TR13 is rated for secondary lightning protection per IEC61000-4-5 with 42 Ω source impedance up to Class 3 (VWM ≤ 24 V), covering its 18 V standoff rating. Its 500 W peak pulse power and 29.2 V clamping voltage ensure compliance when applied with proper PCB layout and grounding - validated in Microsemi's application guidance.
SMAJ18AE3/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):
- 18V
- Voltage - Breakdown (Min):
- 20V
- Voltage - Clamping (Max) @ Ipp:
- 29.2V
- Current - Peak Pulse (10/1000µs):
- 17.2A
- 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)
SMAJ18AE3/TR13 FAQ
1.How can I place an order for SMAJ18AE3/TR13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ18AE3/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 SMAJ18AE3/TR13 reliable?
The price and inventory of SMAJ18AE3/TR13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ18AE3/TR13 is usually 5 days.
3.What payment methods are accepted for SMAJ18AE3/TR13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ18AE3/TR13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ18AE3/TR13?
SMAJ18AE3/TR13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ18AE3/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 SMAJ18AE3/TR13?
For technical support, including SMAJ18AE3/TR13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ18AE3/TR13 requirements.
6.How does Aetrix verify that SMAJ18AE3/TR13 is sourced from the original manufacturer or authorized distributors?
All SMAJ18AE3/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 SMAJ18AE3/TR13 meets industry standards.
7.What is the process for return or replacement of SMAJ18AE3/TR13?
All SMAJ18AE3/TR13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ18AE3/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 SMAJ18AE3/TR13 part is unused and in its original packaging.
Return procedure for SMAJ18AE3/TR13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ18AE3/TR13 Tags
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ESD9B5.0ST5G
onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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onsemi
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DESD5V0U1BB-7
Diodes Incorporated
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D12V0L1B2LP-7B
Diodes Incorporated
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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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