My Inquiry
My Account
Vishay General Semiconductor - Diodes Division SMAJ18CA-E3/5A
- Part No.:
- SMAJ18CA-E3/5A
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ18CA-E3/5A.pdf
- Description:
- TVS DIODE 18VWM 29.2VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:6,812
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMAJ18CA-E3/5A from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in SMA (DO-214AC) package, designed for robust overvoltage protection of sensitive electronics. It features a 18 V standoff voltage (VWM), 20.0–22.1 V breakdown voltage (VBR) at 1 mA, 29.2 V maximum clamping voltage (VC) at 13.7 A peak pulse current (IPPM), and 400 W peak pulse power (10/1000 μs waveform), commonly deployed on power rails and signal lines in automotive ECUs and industrial sensor interfaces.
For engineers reviewing the SMAJ18CA-E3/5A datasheet, SMAJ18CA-E3/5A pinout, SMAJ18CA-E3/5A application, or SMAJ18CA-E3/5A equivalent, key selection criteria include bidirectional clamping behavior, low clamping ratio (VC/VBR ≈ 1.39), AEC-Q101 qualification eligibility (via HE3/HM3 variants), MSL Level 1 moisture sensitivity, and compatibility with automated SMT placement on 5.0 mm × 5.0 mm copper pads.
Technical Context
This device operates as a silicon avalanche diode optimized for fast transient suppression - responding in <1 ps - with symmetrical conduction in both directions due to its bidirectional construction. Its clamping action begins at VBR (min 20.0 V) and limits induced surges to ≤29.2 V at 13.7 A, enabling reliable protection of 3.3 V/5 V/12 V logic and analog circuitry against ESD, load dump, and inductive switching transients.
Thermal performance is defined by RθJA = 120 °C/W (on standard 0.2" × 0.2" pads) and TJ(max) = +150 °C, supporting operation across -55 °C to +150 °C ambient. The glass-passivated junction ensures stable leakage (<1.0 μA at VWM) and long-term reliability under repetitive surge stress up to 0.01% duty cycle.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18 V - Maximum continuous reverse operating voltage before clamping initiates; defines safe DC/AC working range. |
| VBR (min/max) | 20.0 V / 22.1 V at 1 mA - Breakdown threshold range; ensures consistent avalanche turn-on across production lot. |
| VC @ IPPM | 29.2 V at 13.7 A - Clamped voltage during 10/1000 μs surge; determines protected circuit's worst-case overvoltage exposure. |
| PPPM | 400 W (10/1000 μs) - Peak surge energy handling capacity; supports IEC 61000-4-5 Level 3/4 compliance when properly laid out. |
| ID @ VWM | ≤1.0 μA - Reverse leakage at rated standoff; negligible power loss and noise contribution in standby. |
| TJ(max) | +150 °C - Maximum junction temperature; enables use in under-hood automotive and high-ambient industrial environments. |
| Package | SMA (DO-214AC) - Surface-mount outline with 5.28 mm × 4.50 mm footprint; compatible with JEDEC-standard reflow profiles. |
Pinout & Package
Package: SMA (DO-214AC), molded plastic case with matte tin-plated leads, MSL Level 1, UL 94 V-0 rated compound. Bidirectional configuration has no polarity marking; terminals are symmetric and interchangeable.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Transient current entry (either direction) | One terminal of symmetrical PN junction; accepts surge current regardless of polarity. |
| Cathode | Transient current exit (either direction) | Second terminal of symmetrical PN junction; completes low-impedance path to ground or rail during clamping. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC-coupled or floating signal lines without polarity concerns. |
| 400 W peak pulse power | Supports robust immunity to 10/1000 μs surges per IEC 61000-4-5, including automotive load dump events. |
| Low clamping voltage (29.2 V) | Minimizes stress on downstream 3.3 V/5 V ICs when protecting 12 V or 24 V supply domains. |
| MSL Level 1 rating | Permits unlimited floor life and standard reflow without baking; simplifies SMT manufacturing flow. |
| AEC-Q101 qualification path | HE3/HM3 variants available for automotive applications requiring qualified components per ISO/TS 16949. |
Applications
| Automotive Body Control Module (BCM) | Industrial CAN Transceiver Protection |
|---|---|
Use Scenario: Protecting LIN bus interface and power inputs in door module ECUs exposed to battery transients and ESD. IC Role / Device Role / Timing Role: TVS diode placed directly at connector entry point to shunt >100 V load dump spikes before reaching MCU and level translators. Use Value: Prevents latch-up or permanent damage to 5 V microcontrollers and LIN transceivers during vehicle jump-start or alternator regulation faults. | Use Scenario: Safeguarding differential CANH/CANL pins of isolated transceivers in factory automation PLC I/O modules. IC Role / Device Role / Timing Role: Bidirectional clamping element mounted adjacent to transceiver package to clamp common-mode surges induced by motor drive noise. Use Value: Maintains CAN bus integrity under repetitive 1 kV/500 A surge stress (IEC 61000-4-5), avoiding communication dropouts or node resets. |
| Consumer Smart Appliance Motor Drive | Telecom Power Supply Input Stage |
Use Scenario: Suppressing inductive kickback from brushed DC motors in washing machine control boards. IC Role / Device Role / Timing Role: Parallel-connected TVS across motor terminals to absorb back-EMF energy during MOSFET turn-off transitions. Use Value: Eliminates voltage overshoot exceeding 60 V, preventing gate oxide rupture in half-bridge drivers and reducing radiated EMI. | Use Scenario: Front-end protection of 48 V telecom rectifier outputs feeding PoE injectors and baseband processors. IC Role / Device Role / Timing Role: Standoff-rated TVS placed between +48 V rail and chassis ground to clamp lightning-induced surges entering via AC input or Ethernet ports. Use Value: Limits transient excursions to ≤29.2 V, ensuring downstream DC-DC converters remain within absolute maximum ratings during outdoor cabinet 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 |
|---|---|---|---|
| SMAJ18A-E3/5A | Unidirectional variant; same VWM, VBR, VC, and package but asymmetric conduction (cathode-banded). | Requires polarity-aware layout; unsuitable for AC or floating lines where voltage reversal occurs. | Select only when protecting DC rails with known fixed polarity and space-constrained unidirectional routing. |
| SMBJ18CA-E3/52 | Same VWM/VBR/VC specs but in larger SMB (DO-214AA) package; higher thermal mass (RθJA = 80 °C/W vs. 120 °C/W). | Better surge energy dissipation margin; requires larger PCB area and different pad layout. | Prefer when system-level testing shows marginal thermal margin with SMAJ18CA-E3/5A under repetitive surge conditions. |
Compared with SMAJ18CA-E3/5A, the unidirectional SMAJ18A-E3/5A offers identical electrical protection but demands strict polarity alignment, while the SMBJ18CA-E3/52 provides superior thermal derating at the cost of board space - making SMAJ18CA-E3/5A optimal for compact, polarity-agnostic, high-volume SMT designs.
Availability
SMAJ18CA-E3/5A is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor interfaces, consumer appliance motor controls, and telecom power input stages requiring stable component supply and RoHS-compliant sourcing.
Supply support for SMAJ18CA-E3/5A 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, precision, and automotive-grade qualification.
The SMAJ series is engineered specifically for high-reliability transient suppression in harsh environments - targeting automotive, industrial, and telecom systems where robustness against ESD, EFT, and surge events is mission-critical.
FAQ
What is the clamping voltage of SMAJ18CA-E3/5A at its rated peak pulse current?
The SMAJ18CA-E3/5A exhibits a maximum clamping voltage (VC) of 29.2 V when subjected to its rated peak pulse current (IPPM) of 13.7 A under the standard 10/1000 μs waveform. This value is measured per Figure 1 in Vishay document 88390 and defines the upper voltage limit imposed on protected circuitry during surge events. The SMAJ18CA-E3/5A maintains this clamping performance consistently across its operating temperature range.
Is SMAJ18CA-E3/5A suitable for automotive applications requiring AEC-Q101 qualification?
The SMAJ18CA-E3/5A itself is the commercial-grade RoHS-compliant variant; however, Vishay offers AEC-Q101 qualified versions under ordering codes SMAJ18CAHE3_X (RoHS + AEC-Q101) and SMAJ18CAHM3_X (halogen-free + AEC-Q101). These share identical electrical specs and SMA package with SMAJ18CA-E3/5A but undergo additional stress testing per AEC-Q101. For automotive use, specify the HE3 or HM3 suffix variant instead of SMAJ18CA-E3/5A.
How does the bidirectional nature of SMAJ18CA-E3/5A affect PCB layout compared to unidirectional TVS diodes?
Unlike unidirectional TVS diodes such as SMAJ18A-E3/5A - which require cathode alignment toward the protected line's reference potential - SMAJ18CA-E3/5A has no polarity marking and functions identically regardless of orientation. This eliminates orientation-dependent assembly errors and allows flexible placement on AC-coupled, differential, or floating nodes. The SMAJ18CA-E3/5A terminals are fully interchangeable, simplifying layout and reducing BOM complexity in mixed-signal systems.
What is the maximum allowable printed circuit board copper pad size for thermal performance validation of SMAJ18CA-E3/5A?
Vishay specifies thermal ratings for SMAJ18CA-E3/5A using 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal, as stated in Note (2) of the Maximum Ratings table. Derating curves (Figure 2) assume this pad size. Reducing pad area increases RθJA beyond the rated 120 °C/W and may cause premature thermal failure under repetitive surges. To maintain datasheet performance, ensure each SMAJ18CA-E3/5A terminal connects to ≥5.0 mm × 5.0 mm copper area, preferably with internal layer thermal vias.
Does SMAJ18CA-E3/5A meet any industry-standard surge immunity requirements out-of-the-box?
The SMAJ18CA-E3/5A is not certified to any immunity standard (e.g., IEC 61000-4-2/4-4/4-5) as a standalone component; rather, it is a building-block device whose performance depends on PCB layout, grounding, and system-level design. However, its 400 W peak pulse power rating (10/1000 μs), low clamping ratio, and fast response enable compliant designs when implemented per Vishay's recommended layout - particularly for IEC 61000-4-5 Level 3 (1 kV line-earth, 2 kV line-line) in conjunction with proper filtering and grounding of the SMAJ18CA-E3/5A.
SMAJ18CA-E3/5A 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):
- 18V
- Voltage - Breakdown (Min):
- 20V
- Voltage - Clamping (Max) @ Ipp:
- 29.2V
- Current - Peak Pulse (10/1000µs):
- 13.7A
- 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)
SMAJ18CA-E3/5A FAQ
1.How can I place an order for SMAJ18CA-E3/5A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ18CA-E3/5A 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 SMAJ18CA-E3/5A reliable?
The price and inventory of SMAJ18CA-E3/5A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ18CA-E3/5A is usually 5 days.
3.What payment methods are accepted for SMAJ18CA-E3/5A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ18CA-E3/5A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ18CA-E3/5A?
SMAJ18CA-E3/5A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ18CA-E3/5A 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 SMAJ18CA-E3/5A?
For technical support, including SMAJ18CA-E3/5A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ18CA-E3/5A requirements.
6.How does Aetrix verify that SMAJ18CA-E3/5A is sourced from the original manufacturer or authorized distributors?
All SMAJ18CA-E3/5A 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 SMAJ18CA-E3/5A meets industry standards.
7.What is the process for return or replacement of SMAJ18CA-E3/5A?
All SMAJ18CA-E3/5A units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ18CA-E3/5A, 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 SMAJ18CA-E3/5A part is unused and in its original packaging.
Return procedure for SMAJ18CA-E3/5A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ18CA-E3/5A 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 …
