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Diodes Incorporated P4SMAJ18ADF-13
- Part No.:
- P4SMAJ18ADF-13
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- 2-SMD, Flat Leads
- Datasheet:
-
P4SMAJ18ADF-13.pdf
- Description:
- TVS DIODE 18VWM 29.2VC D-FLAT
- Quantity:
- Payment:
- Shipping:
Inventory:9,767
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Product details
Overview
P4SMAJ18ADF-13 from Diodes Incorporated is a 400W surface-mount transient voltage suppressor (TVS) diode designed for unidirectional overvoltage protection in DC power rails and signal lines. It features a reverse standoff voltage of 18 V, clamping voltage of 29.2 V at 13.7 A peak pulse current, and IEC 61000-4-2 ESD rating of ±30 kV (air/contact). It is used in industrial power supplies, automotive body electronics, and USB interface protection circuits.
For engineers reviewing the P4SMAJ18ADF-13 datasheet, P4SMAJ18ADF-13 pinout, P4SMAJ18ADF-13 application, or P4SMAJ18ADF-13 equivalent, this page delivers verified electrical parameters, D-FLAT package layout, clamping behavior under 10/1000 µs transients, and real-world substitution guidance for surge protection design.
Technical Context
This TVS diode operates as a unidirectional avalanche clamp, triggered when reverse voltage exceeds its 20.0–22.1 V breakdown range at 1.0 mA test current. Its low clamping ratio (VC/VRWM ≈ 1.62) ensures minimal overvoltage stress on downstream ICs during ESD or lightning-induced surges.
Thermal performance is defined by junction-to-terminal resistance of 37 °C/W (FR-4, 1"×1", 2 oz copper pad) and junction-to-ambient resistance of 114 °C/W under standard mounting. It sustains 40 A non-repetitive forward surge current per 8.3 ms half-sine waveform with ≤4 pulses/minute duty cycle.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 400 W - Sustains single 10×1000 µs transients without failure under specified thermal conditions. |
| Reverse Standoff Voltage (VRWM) | 18 V - Maximum continuous DC operating voltage before significant leakage; sets minimum system rail compatibility. |
| Breakdown Voltage (VBR) | 20.0–22.1 V @ 1.0 mA - Confirmed avalanche initiation window; determines turn-on margin above VRWM. |
| Clamping Voltage (VC) | 29.2 V @ 13.7 A IPP - Maximum voltage seen by protected circuit during worst-case transient; defines safe IC stress limit. |
| ESD Rating | ±30 kV (IEC 61000-4-2, air & contact) - Validates robustness against human-body-model electrostatic discharge events. |
| Junction-to-Ambient RθJA | 114 °C/W - Thermal resistance under standard FR-4 mounting; used to calculate max ambient temperature for 150°C junction limit. |
| Capacitance | 10 pF @ 1 MHz, 0 V - Low parasitic capacitance preserves signal integrity in high-speed data lines (e.g., CAN, RS-485). |
Pinout & Package
Package: D-FLAT - Low-profile, surface-mount plastic package (2.25–2.95 mm width × 3.95–4.60 mm length × 0.90–1.10 mm height), UL 94V-0 rated, with cathode band polarity indicator and matte tin–annealed copper leadframe.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Cathode) | Transient Current Sink | Connected to protected line; conducts surge current to ground when voltage exceeds VBR. |
| 2 (Anode) | Reference / Ground Return | Typically tied to system ground; completes clamping path during overvoltage events. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated die construction | Ensures stable VBR tolerance and long-term reliability under thermal cycling and humidity exposure. |
| Low-profile D-FLAT package | Reduces PCB footprint by >30% vs. SMA; enables dense routing in space-constrained industrial modules. |
| Lead-free, halogen-free, RoHS 3 compliant | Meets IPC-J-STD-020 moisture sensitivity Level 1 and global environmental compliance mandates. |
| 400 W peak pulse rating | Provides higher surge immunity than 200 W TVS devices, enabling fewer components per rail in multi-transient environments. |
Applications
| Industrial Power Input Protection | Automotive Body Control Module (BCM) |
|---|---|
Use Scenario: 24 V DC input stage of programmable logic controllers exposed to load dump and ISO 7637-2 pulses. IC Role / Device Role: Unidirectional TVS clamp placed between input rail and ground to limit transient overshoot. Use Value: Clamps 13.7 A surges to ≤29.2 V, protecting downstream DC-DC converters rated for 36 V absolute maximum. |
Use Scenario: LIN bus transceiver power supply line in door module subjected to battery reversal and jump-start spikes. IC Role / Device Role: Primary overvoltage suppression element on VCC rail upstream of regulator. Use Value: Withstands 40 A 8.3 ms surge (load dump), preventing latch-up or burnout of 5 V LDOs and microcontrollers. |
| USB 2.0 Data Line Protection | RS-485 Transceiver Interface |
Use Scenario: D+ and D− lines of embedded USB host port facing ESD events during cable insertion. IC Role / Device Role: Low-capacitance (10 pF) bidirectional protection via dual unidirectional configuration. Use Value: Maintains signal rise/fall times <1 ns while passing ±30 kV IEC 61000-4-2 ESD without bit errors. |
Use Scenario: Termination point of RS-485 differential pair in factory automation gateway exposed to ground potential differences. IC Role / Device Role: Common-mode TVS pair (one per line) referenced to local ground. Use Value: Limits common-mode transients to <29.2 V, preserving receiver input common-mode range (−7 V to +12 V). |
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-Q | Same 18 V VRWM, but lower 400 W rating and higher clamping voltage (32.4 V @ 12.3 A); JEDEC-standard SMA package (larger footprint). | Less effective clamping margin in 3.3 V/5 V logic protection; requires larger PCB area. | Select only if D-FLAT footprint is incompatible and thermal derating allows higher VC. |
| SMCJ18A | Same 18 V VRWM, 1500 W rating, 28.8 V clamping @ 52.1 A; DO-214AB package (5.59 mm × 6.92 mm). | Overqualified for 400 W needs; introduces unnecessary cost and board space in compact designs. | Prefer for high-energy surge zones (e.g., AC front-end); avoid where size and cost are constrained. |
Compared with SMAJ18A-Q and SMCJ18A, P4SMAJ18ADF-13 delivers optimal balance of low-profile packaging, precise 29.2 V clamping, and validated 400 W capability-making it ideal for space-limited industrial and automotive ECUs where both footprint and clamping accuracy matter.
Availability
P4SMAJ18ADF-13 is available at Aetrix Electronics and suitable for industrial power input protection, automotive body control modules, USB 2.0 data line protection, and RS-485 transceiver interface applications requiring stable component supply and full RoHS 3 compliance.
Supply support for P4SMAJ18ADF-13 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the Americas.
The P4SMAJ series belongs to Diodes' transient voltage suppressor portfolio, engineered specifically for high-reliability, low-footprint surge protection in automotive, industrial, and communications equipment where ESD robustness and thermal stability are critical.
FAQ
What is the maximum operating temperature for P4SMAJ18ADF-13?
The device supports an operating junction temperature range of −55 °C to +150 °C. Under typical FR-4 mounting (1"×1", 2 oz copper), its thermal resistance (RθJA = 114 °C/W) limits ambient temperature to approximately +85 °C at full 400 W pulse dissipation. Derating curves in Figure 1 confirm 50% power capability at +75 °C ambient.
Is P4SMAJ18ADF-13 bidirectional or unidirectional?
P4SMAJ18ADF-13 is a unidirectional TVS diode, configured as a single avalanche junction with cathode-anode polarity. It protects against positive transients on the cathode side relative to anode (ground). For bidirectional protection, two devices must be used in series-opposing configuration or a dedicated bidirectional part selected.
How does its clamping voltage compare to SMAJ18A?
P4SMAJ18ADF-13 clamps at 29.2 V @ 13.7 A (10×1000 µs), while SMAJ18A clamps at 32.4 V @ 12.3 A under identical conditions. This 3.2 V lower clamping voltage provides tighter overvoltage margin for 3.3 V and 5 V logic rails, reducing risk of damage to sensitive receivers.
Can it replace P4SMAJ18A in existing designs?
Yes-P4SMAJ18ADF-13 is a direct drop-in replacement for P4SMAJ18A, sharing identical D-FLAT package dimensions, marking code "IT", electrical specifications, and thermal characteristics. The "-13" suffix denotes 10,000-piece tape-and-reel packaging, fully compatible with automated SMT placement.
P4SMAJ18ADF-13 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- 2-SMD, Flat Leads
- 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):
- 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:
- D-Flat
P4SMAJ18ADF-13 FAQ
1.How can I place an order for P4SMAJ18ADF-13 through Aetrix?
Please submit a Request for Quotation (RFQ) for P4SMAJ18ADF-13 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 P4SMAJ18ADF-13 reliable?
The price and inventory of P4SMAJ18ADF-13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for P4SMAJ18ADF-13 is usually 5 days.
3.What payment methods are accepted for P4SMAJ18ADF-13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for P4SMAJ18ADF-13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for P4SMAJ18ADF-13?
P4SMAJ18ADF-13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your P4SMAJ18ADF-13 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 P4SMAJ18ADF-13?
For technical support, including P4SMAJ18ADF-13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your P4SMAJ18ADF-13 requirements.
6.How does Aetrix verify that P4SMAJ18ADF-13 is sourced from the original manufacturer or authorized distributors?
All P4SMAJ18ADF-13 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 P4SMAJ18ADF-13 meets industry standards.
7.What is the process for return or replacement of P4SMAJ18ADF-13?
All P4SMAJ18ADF-13 units undergo pre-shipment inspection (PSI). If there is an issue with P4SMAJ18ADF-13, 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 P4SMAJ18ADF-13 part is unused and in its original packaging.
Return procedure for P4SMAJ18ADF-13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
P4SMAJ18ADF-13 Tags
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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