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Taiwan Semiconductor Corporation P4SMA18AH
- Part No.:
- P4SMA18AH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
P4SMA18AH.pdf
- Description:
- TVS DIODE 15.3VWM 25.5VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:7,390
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Product details
Overview
P4SMA18AH from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, rated for 400W peak pulse power, 17.1–18.9V breakdown voltage at 1mA, and 25.5V clamping voltage at 16.5A (10/1000μs waveform), designed to protect DC/DC converters and automotive power rails against ESD and surge transients.
For engineers reviewing the P4SMA18AH datasheet, P4SMA18AH pinout, P4SMA18AH application, or P4SMA18AH equivalent, key selection criteria include its AEC-Q101 qualification, <1.0ps response time, 1μA max reverse leakage at 15.3V, ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance, and unidirectional polarity with cathode band marking.
Technical Context
The P4SMA18AH operates as a unidirectional avalanche diode with glass-passivated junction, optimized for fast clamping of transient overvoltages on low-voltage DC lines. Its 15.3V working stand-off voltage ensures reliable blocking during normal operation while allowing rapid conduction above 17.1V breakdown threshold.
It delivers 400W peak pulse power under 10/1000μs waveform, supports 40A non-repetitive forward surge current, and maintains stable performance across –55°C to +150°C junction temperature range - meeting automotive-grade reliability requirements per AEC-Q101 and moisture sensitivity level 1 (J-STD-020).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR @ IT=1mA | 17.1–18.9V: Ensures precise, repeatable avalanche turn-on within tight tolerance for predictable protection threshold |
| VWM | 15.3V: Maximum continuous reverse voltage before significant leakage; sets safe operating margin below VBR |
| VC @ IPPM=16.5A | 25.5V: Clamped voltage during 400W transient; defines worst-case overvoltage seen by downstream circuitry |
| IR @ VWM | <1μA: Negligible standby power loss and minimal signal interference in high-impedance circuits |
| PPPM | 400W (10/1000μs): Sustains high-energy surges common in automotive load-dump and ISO 7637-2 test pulses |
| TJ Range | –55°C to +150°C: Fully qualified for under-hood and industrial environments without derating |
| Response Time | <1.0ps: Faster than most semiconductor switching events, enabling effective suppression of ESD and fast transients |
Pinout & Package
Package: DO-214AC (SMA), surface-mount, single-diode configuration with cathode band marking. Matte tin-plated leads, UL 94V-0 molding compound, 0.060g weight.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry / Surge return path | Connected to protected line (e.g., +12V rail); conducts transient energy to ground when clamped |
| Cathode | Reverse-biased terminal / Reference node | Connected to system ground; polarity mark (band) identifies this terminal for correct PCB placement |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including engine control, body electronics, and ADAS power domains |
| Glass passivated junction | Enhances long-term reliability and stability of breakdown voltage under thermal cycling and humidity stress |
| ISO 7637-2 compliance | Withstands Pulse 1 (inductive switch-off), Pulse 2a/2b (battery disconnect), and Pulse 3a/3b (capacitive coupling) waveforms |
| Moisture sensitivity level 1 | Zero bake requirement prior to reflow; compatible with standard SMT assembly processes without floor-life restrictions |
| RoHS & halogen-free | Meets IEC 61249-2-21 and EU RoHS directives for environmentally compliant manufacturing and end-of-life handling |
Applications
| Automotive Power Rail Protection | On-Board DC/DC Converter Input |
|---|---|
Use Scenario: Protecting 12V battery-fed ECUs from load dump and alternator transients in passenger vehicles. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed between power input and chassis ground to clamp surges before they reach regulator ICs. Use Value: Limits peak voltage to ≤25.5V during 400W transients, preventing damage to 36V-rated input stages of buck controllers like LM5143A. | Use Scenario: Safeguarding primary-side input of isolated 12V-to-5V DC/DC modules in infotainment head units. IC Role / Device Role / Timing Role: Standoff protector absorbing coupled noise and ESD from adjacent connectors or harnesses. Use Value: 15.3V VWM avoids false triggering during nominal 12V ±10% operation while clamping fast edges within 1ps. |
| Industrial SMPS Input Stage | LED Driver Power Input |
Use Scenario: Front-end surge protection for DIN-rail mounted 24V AC/DC supplies used in factory automation. IC Role / Device Role / Timing Role: Primary transient shunt on rectified DC bus, coordinated with MOV and fuse for multi-level protection. Use Value: 400W rating handles repetitive 1kV/2Ω surge tests per IEC 61000-4-5; 1μA leakage minimizes standby loss. | Use Scenario: Input protection for constant-current LED drivers in streetlight systems exposed to lightning-induced surges. IC Role / Device Role / Timing Role: Fast-response clamp on 24–48V DC input, placed upstream of PWM controller and MOSFET gate driver. Use Value: 25.5V clamping ensures LED string and driver IC remain below absolute maximum ratings during 10/1000μs transients. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ18A | DO-214AA (SMB) package; 600W rating; 18.9–20.9V VBR; 29.2V VC @ 20.5A | Higher clamping voltage and larger footprint; better suited for higher-energy surges where board space allows | Select SMBJ18A when 600W pulse handling is required and DO-214AA layout is already established |
| 1.5SMC18A | DO-214AB (SMC) package; 1500W rating; 18.9–20.9V VBR; 29.2V VC @ 51.3A | Substantially higher power rating and thermal mass; intended for main power input protection rather than point-of-load | Choose 1.5SMC18A for primary DC bus protection where sustained surge energy exceeds 400W capability |
Compared with SMBJ18A and 1.5SMC18A, the P4SMA18AH offers optimal balance of compact DO-214AC size, AEC-Q101 qualification, and 400W capability - making it ideal for space-constrained automotive and industrial point-of-load protection where strict leakage (<1μA) and fast response (<1ps) are critical.
Availability
P4SMA18AH is available at Aetrix Electronics and suitable for automotive power rail protection, on-board DC/DC converter input stages, and industrial SMPS front-end surge suppression requiring stable component supply and full AEC-Q101 traceability.
Supply support for P4SMA18AH 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 analog and discrete device manufacturer headquartered in Hsinchu, Taiwan, serving global automotive, industrial, and consumer markets since 1979.
The P4SMA18AH belongs to TSC's AEC-Q101-qualified P4SMAx(A)H series of surface-mount TVS diodes, engineered specifically for robust transient immunity in automotive power distribution and industrial DC power systems.
FAQ
Is P4SMA18AH unidirectional or bidirectional?
The P4SMA18AH is a unidirectional TVS diode, indicated by the absence of "C" prefix (e.g., "CAH") and confirmed by its single cathode band marking and electrical specifications applying only in reverse bias. It protects positive-going transients on grounded systems and must be oriented with cathode toward the protected line's reference ground.
What is the maximum clamping voltage of P4SMA18AH under standard test conditions?
The P4SMA18AH has a maximum clamping voltage (VC) of 25.5V at 16.5A peak pulse current using the 10/1000μs waveform. This value is measured per ANSI/IEEE C62.35 and defines the upper voltage limit imposed on protected circuitry during a 400W transient event.
Does P4SMA18AH meet automotive qualification standards?
Yes, the P4SMA18AH is AEC-Q101 qualified and meets ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b requirements. It also complies with J-STD-020 moisture sensitivity level 1 and JESD201 class 2 whisker resistance - confirming suitability for automotive under-hood and body electronics applications.
What is the reverse leakage current specification for P4SMA18AH at its working voltage?
At its rated working stand-off voltage (VWM) of 15.3V, the P4SMA18AH exhibits a maximum reverse leakage current (IR) of 1μA at 25°C. This ultra-low leakage preserves efficiency in battery-powered and high-impedance sensing circuits without compromising protection integrity.
Can P4SMA18AH be used in place of P4SMA18H?
Yes, the P4SMA18AH is the tighter-tolerance variant of P4SMA18H, with breakdown voltage specified as 17.1–18.9V (vs. 16.2–19.8V for P4SMA18H) and identical VWM, VC, and power ratings. The "A" suffix denotes improved VBR uniformity, making P4SMA18AH preferable where precise clamping threshold is required.
P4SMA18AH Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AC, SMA
- Series:
- P4SMA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 15.3V
- Voltage - Breakdown (Min):
- 17.1V
- Voltage - Clamping (Max) @ Ipp:
- 25.5V
- Current - Peak Pulse (10/1000µs):
- 16.5A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
P4SMA18AH FAQ
1.How can I place an order for P4SMA18AH through Aetrix?
Please submit a Request for Quotation (RFQ) for P4SMA18AH 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 P4SMA18AH reliable?
The price and inventory of P4SMA18AH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for P4SMA18AH is usually 5 days.
3.What payment methods are accepted for P4SMA18AH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for P4SMA18AH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for P4SMA18AH?
P4SMA18AH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your P4SMA18AH 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 P4SMA18AH?
For technical support, including P4SMA18AH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your P4SMA18AH requirements.
6.How does Aetrix verify that P4SMA18AH is sourced from the original manufacturer or authorized distributors?
All P4SMA18AH 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 P4SMA18AH meets industry standards.
7.What is the process for return or replacement of P4SMA18AH?
All P4SMA18AH units undergo pre-shipment inspection (PSI). If there is an issue with P4SMA18AH, 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 P4SMA18AH part is unused and in its original packaging.
Return procedure for P4SMA18AH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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