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Taiwan Semiconductor Corporation SMCJ18AH
- Part No.:
- SMCJ18AH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ18AH.pdf
- Description:
- TVS DIODE 18VWM 29.2VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:6,794
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Product details
Overview
SMCJ18AH from Taiwan Semiconductor is a unidirectional 1500W transient voltage suppressor (TVS) diode in DO-214AB (SMC) package, with 18V working stand-off voltage (VWM), 20–22.1V breakdown voltage (VBR), and 29.2V maximum clamping voltage (VC) at 53A peak pulse current. It delivers AEC-Q101 qualification and meets ISO 7637-2 Pulse 1/2a/2b/3a/3b for automotive load-dump and ESD protection in power rails.
For engineers reviewing the SMCJ18AH datasheet, SMCJ18AH pinout, SMCJ18AH application, or SMCJ18AH equivalent, this device is selected for high-energy transient suppression in 12V automotive subsystems, industrial DC power inputs, and telecom interface protection where fast response (<1.0 ps), low leakage (<1 µA @ 18V), and robust 1500W surge handling are required.
Technical Context
The SMCJ18AH uses a glass-passivated silicon junction optimized for unidirectional transient clamping. Its 29.2V clamping voltage at 53A ensures safe voltage limiting during ISO 7637-2 Pulse 5a (load dump) events on 12V systems, while its 10°C/W junction-to-case thermal resistance supports sustained power dissipation under repeated surges.
Designed for surface-mount automated placement, it features matte tin-plated leads compliant with J-STD-002 solderability and JESD 201 Class 2 whisker resistance. Polarity is marked by cathode band; moisture sensitivity level is J-STD-020 Level 1.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18 V - Maximum continuous reverse operating voltage before clamping begins; matches nominal 12V system rail with margin for ripple and tolerance. |
| VBR min/max | 20 V / 22.1 V - Breakdown occurs within this range at 1 mA test current; ensures reliable turn-on without premature conduction. |
| VC @ IPPM | 29.2 V - Clamped voltage at 53 A peak pulse (10/1000 µs); limits downstream IC stress during 1500 W transients. |
| PPK | 1500 W - Peak pulse power rating per 1 ms waveform; defines single-event surge energy handling capability. |
| IR @ VWM | <1 µA - Reverse leakage at 18 V; negligible power loss and signal integrity impact in standby operation. |
| TJ max | +150 °C - Maximum junction temperature; enables use in under-hood automotive environments with derating. |
| RθJC | 10 °C/W - Junction-to-case thermal resistance; allows effective heat transfer to PCB copper when mounted with adequate thermal pad. |
Pinout & Package
Package: DO-214AB (SMC), surface-mount, unidirectional configuration with cathode band marking. Case meets UL 94V-0 flammability rating; weight ≈ 0.210 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to ground or low-potential node; completes clamping path during positive transients on cathode side. |
| Cathode | High-side transient input terminal | Connected to protected line (e.g., 12V supply rail); conducts surge current to anode when voltage exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing per stress test plan. |
| Clamping ratio VC/VBR | 1.32 (29.2 V / 22.1 V max) - Tight ratio ensures predictable overvoltage limiting without excessive headroom. |
| Fast response time | <1.0 ps - Enables suppression of nanosecond-scale ESD events before sensitive circuitry reacts. |
| ISO 7637-2 compliance | Validated for Pulse 1 (inductive switch-off), Pulse 2a/2b (battery disconnect), and Pulse 3a/3b (line transients) - covers full automotive EMC immunity scope. |
| Moisture sensitivity | Level 1 per J-STD-020 - No dry-pack or bake requirement prior to reflow; simplifies manufacturing flow. |
Applications
| Automotive Body Control Module (BCM) | Industrial 24V PLC Input Terminal |
|---|---|
Use Scenario: Protecting microcontroller I/O and CAN transceiver power rails from load dump and jump-start transients in BCM modules. IC Role / Device Role / Timing Role: Unidirectional TVS placed between 12V supply and ground, clamping surges before they reach LDOs and communication ICs. Use Value: Limits voltage to ≤29.2 V during 1500 W pulses, preventing latch-up or permanent damage to 3.3V/5V logic supplies downstream. | Use Scenario: Safeguarding analog input protection networks in programmable logic controller (PLC) field terminals exposed to inductive kickback from solenoids and relays. IC Role / Device Role / Timing Role: Primary surge shunt on 24V DC input rail, coordinated with series impedance and filtering capacitors. Use Value: Absorbs 53 A peak current (10/1000 µs) without degradation, maintaining <1 µA leakage to preserve measurement accuracy in high-impedance sensing paths. |
| Telecom PoE Power Sourcing Equipment (PSE) | Consumer USB-C Power Delivery Adapter |
Use Scenario: Secondary-level transient protection on 48V DC output rails of PoE PSE switches subjected to cable discharge and lightning-induced surges. IC Role / Device Role / Timing Role: Standoff-rated TVS on secondary-side DC bus, activated only during overvoltage events exceeding 18V. Use Value: Clamps to 29.2 V within <1 ps, protecting IEEE 802.3bt-compliant PD interface controllers and isolation components from destructive overvoltage. | Use Scenario: Input-stage surge suppression on 20V PP (USB-C PD) input rails in compact AC/DC adapters vulnerable to mains-coupled transients. IC Role / Device Role / Timing Role: First-line unidirectional clamp on primary-side DC bus after bridge rectifier and bulk capacitor. Use Value: Withstands 1500 W single-pulse energy and maintains stable VBR across -55°C to +150°C, ensuring consistent protection in thermally constrained enclosures. |
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 | 600 W PPK rating, SMA package (smaller footprint, higher RθJA = 110°C/W) | Lower surge capacity; suitable only for non-automotive, lower-energy environments (e.g., consumer USB ports) | Select SMCJ18AH when 1500 W surge immunity and AEC-Q101 compliance are mandatory. |
| TPSMD18A | 1500 W PPK, same DO-214AB package, but VBR = 20–23.1 V and VC = 30.0 V (slightly higher clamping) | Identical mechanical fit and thermal performance; minor clamping voltage trade-off | Choose TPSMD18A if sourcing flexibility is prioritized and 0.8 V higher VC is acceptable in system margin analysis. |
Compared with SMAJ18A and TPSMD18A, the SMCJ18AH provides the lowest clamping voltage (29.2 V) among 1500 W DO-214AB TVS diodes at 18 V VWM, tighter VBR tolerance (20–22.1 V), and certified AEC-Q101 qualification-making it optimal for automotive and industrial applications demanding highest reliability and precise overvoltage control.
Availability
SMCJ18AH is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC power inputs, and telecom PoE infrastructure requiring stable component supply, long-term lifecycle support, and AEC-Q101-qualified surge protection.
Supply support for SMCJ18AH 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
Taiwan Semiconductor Corporation (TSC) is a vertically integrated semiconductor manufacturer specializing in discrete power devices, TVS diodes, and rectifiers with global distribution and AEC-Q101 validation capability.
The SMCJ18AH belongs to TSC's high-power surface-mount TVS family designed specifically for automotive and industrial transient immunity-emphasizing low clamping voltage, fast response, and robust surge endurance in harsh environments.
FAQ
What is the clamping voltage of the SMCJ18AH and how is it measured?
The SMCJ18AH has a maximum clamping voltage (VC) of 29.2 V, measured at 53 A peak pulse current using the standardized 10/1000 µs double-exponential waveform per IEC 61000-4-5 and ANSI/IEEE C62.35. This value represents the upper limit of voltage seen by downstream circuitry during worst-case surge events, ensuring compatibility with 3.3 V and 5 V logic supply tolerances when used with appropriate series impedance.
Is the SMCJ18AH suitable for bidirectional transient protection?
No, the SMCJ18AH is a unidirectional TVS diode intended for DC circuits with defined polarity. For bidirectional protection (e.g., AC lines or data buses), Taiwan Semiconductor offers the SMCJ18CAH variant with symmetrical breakdown in both directions. Using SMCJ18AH in reverse-biased AC applications would result in forward conduction and failure.
Does the SMCJ18AH require derating at elevated ambient temperatures?
Yes, the SMCJ18AH must be derated above 25°C ambient per Figure 2 in the datasheet. At 85°C ambient, its 1500 W peak pulse power rating reduces to approximately 900 W due to thermal limitations. Designers must verify clamping performance under worst-case thermal conditions using the published derating curve and junction-to-ambient thermal resistance (RθJA = 55°C/W).
What is the marking code for the SMCJ18AH and how is it identified on the package?
SMCJ18AH is marked with code "GET" on the device body, per the manufacturer's ordering table. The cathode is indicated by a distinct band on the DO-214AB (SMC) package, and the marking appears adjacent to the band. Green compound molding and date code (e.g., "YW") follow standard TSC conventions for traceability.
How does the SMCJ18AH compare to the SMCJ18H in terms of electrical performance?
The SMCJ18AH offers tighter breakdown voltage tolerance (20–22.1 V) versus SMCJ18H (20–24.4 V), resulting in more consistent turn-on behavior and lower maximum clamping voltage (29.2 V vs. 32.2 V). Both share identical package, power rating, and AEC-Q101 qualification, but SMCJ18AH is preferred where precise clamping control and reduced system voltage overshoot are critical.
SMCJ18AH Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AB, SMC
- Series:
- SMCJ
- 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):
- 53A
- Power - Peak Pulse:
- 1500W (1.5kW)
- Power Line Protection:
- No
- Applications:
- Telecom
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AB (SMC)
SMCJ18AH FAQ
1.How can I place an order for SMCJ18AH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ18AH 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 SMCJ18AH reliable?
The price and inventory of SMCJ18AH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ18AH is usually 5 days.
3.What payment methods are accepted for SMCJ18AH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ18AH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ18AH?
SMCJ18AH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ18AH 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 SMCJ18AH?
For technical support, including SMCJ18AH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ18AH requirements.
6.How does Aetrix verify that SMCJ18AH is sourced from the original manufacturer or authorized distributors?
All SMCJ18AH 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 SMCJ18AH meets industry standards.
7.What is the process for return or replacement of SMCJ18AH?
All SMCJ18AH units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ18AH, 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 SMCJ18AH part is unused and in its original packaging.
Return procedure for SMCJ18AH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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