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Vishay General Semiconductor - Diodes Division SMAJ18C-E3/61
- Part No.:
- SMAJ18C-E3/61
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ18C-E3/61.pdf
- Description:
- TVS DIODE 18VWM 32.2VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:4,525
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Product details
Overview
SMAJ18C-E3/61 from Vishay General Semiconductor is a bi-directional transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for clamping ESD and surge transients on signal/power lines. It features 18 V stand-off voltage (VWM), 400 W peak pulse power (10/1000 µs), 32.2 V maximum clamping voltage (VC) at 12.4 A peak pulse current, and operates from −55 °C to +150 °C - used to protect I/O ports of industrial sensors and automotive ECUs against lightning-induced surges.
For engineers reviewing the SMAJ18C-E3/61 datasheet, SMAJ18C-E3/61 pinout, SMAJ18C-E3/61 application, or SMAJ18C-E3/61 equivalent, key selection criteria include bi-directional clamping capability, low leakage (<1 µA at 18 V), RoHS-compliant matte tin terminations, MSL Level 1 rating, and compatibility with automated SMT placement on standard PCB pads.
Technical Context
This bi-directional TVS diode uses a glass-passivated silicon junction to achieve sub-nanosecond response time and low incremental surge resistance. Its symmetrical breakdown behavior ensures identical clamping in both polarities, eliminating polarity marking requirements on the SMA package.
The device is rated for 400 W peak pulse power up to 78 V (derated to 300 W above 78 V), with thermal resistance of 120 °C/W (junction-to-ambient) and 30 °C/W (junction-to-lead) - enabling reliable operation under repetitive surge conditions when mounted on 5.0 × 5.0 mm copper pads per terminal.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18 V - maximum continuous reverse operating voltage before clamping begins; defines safe signal swing range for protected line |
| VC @ IPPM | 32.2 V - clamped voltage at 12.4 A peak pulse current; determines maximum stress imposed on downstream ICs during surge |
| IPPM | 12.4 A - peak surge current survivable with 10/1000 µs waveform; validates protection level against IEC 61000-4-5 Level 3 (1 A–2 A typical) |
| Leakage ID | <1 µA at 18 V - negligible DC loading on high-impedance signal paths such as sensor outputs or communication lines |
| TJ Range | −55 °C to +150 °C - supports operation in under-hood automotive and industrial environments without derating |
| Package | DO-214AC (SMA) - surface-mount outline with 5.28 mm length, 4.50 mm width, and 2.29 mm height; compatible with J-STD-020 MSL Level 1 reflow |
Pinout & Package
DO-214AC (SMA) package: bi-directional device with no polarity marking; two terminals are electrically symmetric and interchangeable.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Transient conduction path | Both terminals conduct identically during positive or negative surges; no cathode band marking required |
| Case | Non-connected mechanical body | Plastic molded case provides insulation and mechanical stability; no thermal or electrical connection to die |
Key Features
| Feature | Design Value |
|---|---|
| Bi-directional clamping | Enables single-device protection of AC-coupled or floating signal lines (e.g., RS-485, CAN, USB D+/D−) without polarity concerns |
| 400 W peak pulse power (10/1000 µs) | Meets IEC 61000-4-5 surge immunity requirements for industrial and automotive applications up to Level 3 |
| Glass-passivated junction | Ensures stable breakdown characteristics over temperature and lifetime; eliminates risk of junction degradation under repeated surge stress |
| RoHS-compliant matte tin plating | Supports lead-free reflow soldering (260 °C, 40 s) and prevents tin whisker growth (JESD 201 Class 1A) |
Applications
| Industrial Sensor Interfaces | Automotive Body Control Modules |
|---|---|
Use Scenario: Protecting analog output lines of pressure/temperature sensors exposed to load dump and inductive switching noise in factory automation systems. IC Role / Device Role / Timing Role: Bi-directional TVS clamp placed directly at connector entry point to shunt transients before reaching ADC input or signal conditioner IC. Use Value: Limits voltage excursion to ≤32.2 V during 1 kV/0.5 Ω surge events, preserving sensor accuracy and preventing microcontroller reset or latch-up. |
Use Scenario: Safeguarding LIN bus transceivers and discrete driver outputs in door module ECUs subjected to ISO 7637-2 Pulse 1/2a/5a. IC Role / Device Role / Timing Role: Primary overvoltage suppression element on LIN data line and 12 V supply rail, located adjacent to connector. Use Value: Clamps 100 V/500 ms load dump spikes to <35 V within nanoseconds, maintaining transceiver functionality and avoiding fuse blowout. |
| Consumer Audio Line Inputs | Telecom DSL Line Cards |
Use Scenario: Shielding unbalanced audio inputs (RCA, 3.5 mm jack) in AV receivers from ESD events during user handling. IC Role / Device Role / Timing Role: First-line ESD protection device placed between jack and op-amp input stage, with minimal parasitic capacitance. Use Value: Provides <1 µA leakage at 18 V and <100 pF junction capacitance, preserving audio bandwidth while passing ±8 kV HBM ESD pulses. |
Use Scenario: Protecting ADSL/VDSL line interface circuits from lightning-induced surges entering via outdoor telephone wiring. IC Role / Device Role / Timing Role: Secondary surge protector cascaded after gas discharge tube (GDT), absorbing residual energy and limiting let-through voltage. Use Value: Delivers 400 W dissipation capability and 32.2 V clamping to hold line voltage below PHY IC absolute maximum ratings during 10/700 µs telecom surges. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ18CA-E3/61 | Same VWM (18 V), identical VC (32.2 V) and IPPM (12.4 A); CA suffix denotes same bi-directional construction as C | No functional difference - CA and C are interchangeable per Vishay documentation for this voltage grade | Select SMAJ18CA-E3/61 only if legacy BOM specifies CA; otherwise SMAJ18C-E3/61 is functionally identical and preferred |
| SMBJ18C-E3/52 | Same VWM (18 V) and bi-directional configuration, but SMB package (DO-214AA) offers higher 600 W peak power and 17.3 A IPPM | Requires larger PCB footprint (5.3 mm × 4.6 mm vs. 4.5 mm × 2.3 mm) and different pad layout; suited for higher-energy surge environments | Choose SMBJ18C-E3/52 only when system-level testing requires >400 W surge handling; otherwise SMAJ18C-E3/61 provides optimal size-power balance |
Compared with SMAJ18CA-E3/61 (identical performance, alternate marking) and SMBJ18C-E3/52 (higher power, larger package), SMAJ18C-E3/61 delivers verified 400 W surge protection in the smallest standardized SMA footprint - making it ideal for space-constrained industrial and automotive PCBs where 12.4 A clamping current suffices.
Availability
SMAJ18C-E3/61 is available at Aetrix Electronics and suitable for industrial sensor interfaces, automotive body control modules, consumer audio line inputs, and telecom DSL line cards requiring stable component supply across production lifecycles.
Supply support for SMAJ18C-E3/61 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 high-reliability diodes, MOSFETs, optoelectronics, and passive components for demanding industrial and automotive applications.
The SMAJ series is engineered specifically for robust transient suppression in harsh environments - delivering consistent clamping performance, AEC-Q101 qualification readiness, and compatibility with automated SMT assembly processes.
FAQ
What is the clamping voltage of SMAJ18C-E3/61 at its rated peak pulse current?
The SMAJ18C-E3/61 has a maximum clamping voltage (VC) of 32.2 V when subjected to its rated 12.4 A peak pulse current (IPPM) with a 10/1000 µs waveform. This value is measured per Figure 1 and Table 1 in Vishay document 88390 and defines the upper voltage limit imposed on protected circuitry during surge events. The SMAJ18C-E3/61 maintains this clamping performance across its full operating temperature range.
Is SMAJ18C-E3/61 suitable for automotive applications?
SMAJ18C-E3/61 meets RoHS compliance and MSL Level 1 reflow requirements, and its base P/N-E3 variant is commercial-grade. While not AEC-Q101 qualified itself, it belongs to the SMAJ family where the HE3-suffix variants (e.g., SMAJ18CHE3) are explicitly AEC-Q101 qualified. Engineers deploying SMAJ18C-E3/61 in automotive contexts must validate system-level reliability per ISO 16750 and perform board-level qualification testing. The SMAJ18C-E3/61 shares identical electrical specs with qualified versions except for screening and traceability.
How does the bi-directional nature of SMAJ18C-E3/61 affect PCB layout?
Because SMAJ18C-E3/61 is bi-directional, its two terminals are functionally identical - no cathode band marking is present, and orientation on the PCB is irrelevant. This simplifies layout by eliminating polarity verification during placement and allows flexible routing in AC-coupled or differential signal paths. The SMAJ18C-E3/61 should still be placed as close as possible to the protected port with short, low-inductance traces to both terminals and ground.
What is the maximum reverse leakage current for SMAJ18C-E3/61 at its stand-off voltage?
The SMAJ18C-E3/61 exhibits a maximum reverse leakage current (ID) of 1.0 µA at its 18 V stand-off voltage (VWM) and 25 °C ambient temperature, per Table 1 in Vishay document 88390. This ultra-low leakage ensures minimal impact on high-impedance signal chains, such as sensor outputs or precision reference lines, without introducing offset or drift. Leakage remains below 5 µA up to +85 °C.
Does SMAJ18C-E3/61 require derating above 25 °C ambient temperature?
Yes - the peak pulse power rating of SMAJ18C-E3/61 is derated linearly above 25 °C ambient, per Figure 2 in Vishay document 88390. At 85 °C ambient, its 400 W rating reduces to approximately 280 W; at 125 °C, it falls to ~180 W. Designers must apply this derating when sizing for worst-case operating environments and ensure adequate PCB copper area (minimum 5.0 × 5.0 mm per terminal) to maintain thermal performance. The SMAJ18C-E3/61's 120 °C/W RθJA informs this calculation.
SMAJ18C-E3/61 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AC, SMA
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 18V
- Voltage - Breakdown (Min):
- 20V
- Voltage - Clamping (Max) @ Ipp:
- 32.2V
- Current - Peak Pulse (10/1000µs):
- 12.4A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ18C-E3/61 FAQ
1.How can I place an order for SMAJ18C-E3/61 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ18C-E3/61 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 SMAJ18C-E3/61 reliable?
The price and inventory of SMAJ18C-E3/61 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ18C-E3/61 is usually 5 days.
3.What payment methods are accepted for SMAJ18C-E3/61?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ18C-E3/61 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ18C-E3/61?
SMAJ18C-E3/61 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ18C-E3/61 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 SMAJ18C-E3/61?
For technical support, including SMAJ18C-E3/61 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ18C-E3/61 requirements.
6.How does Aetrix verify that SMAJ18C-E3/61 is sourced from the original manufacturer or authorized distributors?
All SMAJ18C-E3/61 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 SMAJ18C-E3/61 meets industry standards.
7.What is the process for return or replacement of SMAJ18C-E3/61?
All SMAJ18C-E3/61 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ18C-E3/61, 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 SMAJ18C-E3/61 part is unused and in its original packaging.
Return procedure for SMAJ18C-E3/61:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ18C-E3/61 Tags
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DESD3V3E1BL-7B
Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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