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Taiwan Semiconductor Corporation P4SMA18CH
- Part No.:
- P4SMA18CH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
P4SMA18CH.pdf
- Description:
- 400W, 18V, 10%, BIDIRECTIONAL, T
- Quantity:
- Payment:
- Shipping:
Inventory:4,572
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Product details
Overview
P4SMA18CH from Taiwan Semiconductor is a bidirectional surface-mount transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, rated for 400W peak pulse power (10/1000μs), with a working stand-off voltage of 15.3V, breakdown voltage range 17.1–18.9V at 1mA test current, and clamping voltage of 25.5V at 16.5A peak impulse current. It is AEC-Q101 qualified and meets ISO 7637-2 Pulse 1/2a/2b/3a/3b for automotive electronics protection.
For engineers reviewing the P4SMA18CH datasheet, P4SMA18CH pinout, P4SMA18CH application, or P4SMA18CH equivalent, key selection criteria include bidirectional surge capability, low clamping ratio (VC/VBR ≈ 1.35), moisture sensitivity level 1 compliance, glass-passivated junction reliability, and suitability for DC/DC converter input rail protection in harsh environments.
Technical Context
The P4SMA18CH implements a single-die, bidirectional avalanche structure optimized for fast transient suppression in automotive and industrial power rails. Its <1.0ps response time enables effective clamping of ESD and load-dump transients before downstream circuitry is stressed.
Designed per ANSI/IEEE C62.35, it delivers symmetrical electrical characteristics in both directions - VBR min/max, IR ≤1μA at VWM, and VC defined identically for positive and negative polarity surges - eliminating need for polarity-aware layout in bidirectional protection schemes.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 15.3 V - maximum continuous reverse operating voltage before leakage exceeds 1 μA; sets upper limit for protected line's nominal DC voltage |
| VBR @ IT=1mA | 17.1–18.9 V - guaranteed avalanche initiation range; ensures predictable turn-on during overvoltage events |
| VC @ IPPM=16.5A | 25.5 V - clamped voltage under 10/1000μs surge; defines worst-case stress on downstream ICs |
| PPPM | 400 W - peak pulse power handling (10/1000μs); supports robust protection against ISO 7637-2 Pulse 5a (load dump) |
| IR @ VWM | ≤1 μA - ultra-low reverse leakage at operating voltage; minimizes standby power loss in battery-critical systems |
| TJ max | +150°C - maximum junction temperature; enables operation in under-hood automotive environments |
| Package | DO-214AC (SMA) - industry-standard surface-mount outline with 0.060g mass and J-STD-002 solderable matte tin leads |
Pinout & Package
DO-214AC (SMA) package: molded plastic case with cathode band marking; bidirectional symmetry means no functional polarity - terminals are interchangeable for AC or dual-rail DC protection.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Bidirectional avalanche junction terminal | Either end connects to protected line; no orientation dependency - simplifies PCB layout and automated placement |
| Cathode band (marking) | Manufacturing polarity indicator only | Present for traceability but electrically irrelevant in bidirectional configuration; does not define functional direction |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive-grade reliability including temperature cycling, humidity bias, and mechanical shock per stress test requirements |
| Glass passivated chip junction | Enhances long-term stability and reduces parameter drift under thermal cycling and high-humidity conditions |
| Moisture sensitivity level 1 | Zero floor-life limitation - can be mounted directly from reel without baking, reducing manufacturing overhead |
| ISO 7637-2 compliance (Pulse 1/2a/2b/3a/3b) | Proven immunity to common automotive transient waveforms, enabling drop-in use in CAN/LIN bus power domains and sensor supply lines |
| Halogen-free & RoHS compliant | Meets IEC 61249-2-21 and EU RoHS Directive 2011/65/EU - supports green manufacturing and export compliance |
Applications
| Automotive Infotainment Power Rail | Industrial PLC Digital Input Protection |
|---|---|
Use Scenario: Protecting 12V supply inputs of head unit MCUs and audio amplifiers against load dump and jump-start transients. IC Role / Device Role / Timing Role: Primary bidirectional TVS clamp placed upstream of DC/DC converters and LDOs. Use Value: Clamps to 25.5V during 16.5A surge, limiting stress on 36V-rated input capacitors and preventing brownout-induced MCU resets. | Use Scenario: Safeguarding 24V digital input channels of programmable logic controllers exposed to field-wiring inductive kickback. IC Role / Device Role / Timing Role: Front-end transient absorber on isolated input optocoupler supply path. Use Value: Sub-1ps response captures fast-switching transients before isolation barrier, preserving signal integrity and preventing false triggering. |
| LED Driver Output Stage | On-Board DC/DC Converter Input |
Use Scenario: Suppressing flyback spikes generated by MOSFET switching in constant-current LED drivers for automotive lighting. IC Role / Device Role / Timing Role: Snubber-connected TVS across output inductor or switch node. Use Value: 400W peak power rating handles repetitive 10/1000μs surges without degradation, extending driver lifetime in stop-start cycles. | Use Scenario: Input-side surge protection for buck converters powering ADAS sensors in ADAS domain controllers. IC Role / Device Role / Timing Role: First-line transient suppressor between vehicle battery and converter input capacitor. Use Value: Bidirectional symmetry allows shared protection across dual-supply rails (e.g., +12V and –12V reference), reducing BOM count. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ18CA | 600W rating, SMB package (larger footprint), VBR 19.0–21.0V, VC = 29.2V @ 20.5A | Higher power margin but requires PCB area increase; better suited for 24V systems with higher-energy transients | Select when system-level testing shows >400W surge exposure or when existing layout accommodates SMB footprint |
| 1.5SMC18CA | 1500W rating, SMC package (3.5×3.5mm), VBR 19.0–21.0V, VC = 29.2V @ 51.3A | Over-specified for most 12V applications; used where MIL-STD-1275E compliance is required | Choose only if design must withstand military-grade load dump or repeated high-energy pulses beyond ISO 7637-2 scope |
Compared with SMBJ18CA and 1.5SMC18CA, the P4SMA18CH offers optimal balance of compact DO-214AC footprint, AEC-Q101 validation, and precise 15.3V VWM alignment with 12V automotive systems - making it ideal for space-constrained, cost-sensitive, and production-volume automotive modules.
Availability
P4SMA18CH is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial PLC input modules, and LED driver designs requiring stable component supply with full traceability and lifecycle management.
Supply support for P4SMA18CH 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 semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in TVS diodes, rectifiers, and power devices since 1979.
The P4SMA18CH belongs to TSC's AEC-Q101-qualified P4SMAxH series - engineered specifically for robust, surface-mount transient suppression in automotive power distribution networks and industrial control interfaces.
FAQ
What does the "CH" suffix indicate in P4SMA18CH?
The "CH" suffix in P4SMA18CH denotes a bidirectional variant with AEC-Q101 qualification. Unlike unidirectional "H" versions, the CH type provides symmetrical clamping in both polarities - essential for protecting AC-coupled or dual-rail circuits without polarity constraints. This designation is confirmed in TSC's ordering information and electrical specifications table.
Is P4SMA18CH suitable for ISO 7637-2 Pulse 5a (load dump) protection?
P4SMA18CH is rated for 400W peak pulse power under 10/1000μs waveform, which aligns with ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b - but not Pulse 5a, which demands ≥1000W. For load dump, pairing P4SMA18CH with a series impedance (e.g., 1Ω resistor) or using it as secondary protection behind a dedicated load-dump suppressor is recommended. The datasheet explicitly lists Pulse 5a exclusion.
Does P4SMA18CH require derating at elevated ambient temperatures?
Yes - P4SMA18CH must be derated above TA = 25°C per Figure 2 in the datasheet. At 85°C ambient, its peak pulse power drops to ~260W (65% of 400W), and at 125°C, it falls to ~140W (35%). Designers must apply this derating when placing P4SMA18CH near heat sources such as power inductors or MOSFETs in engine-control units.
Can P4SMA18CH be used in place of a unidirectional P4SMA18H?
No - P4SMA18CH is bidirectional while P4SMA18H is unidirectional. Swapping them without circuit review risks incorrect clamping behavior: P4SMA18CH will conduct on both polarities, potentially disrupting DC bias in unidirectional paths. The cathode band on P4SMA18CH is a manufacturing mark only and does not imply polarity. Always verify schematic topology before substitution.
What is the maximum junction capacitance of P4SMA18CH at 0V bias?
The datasheet does not specify junction capacitance for P4SMA18CH. While Fig.3 shows typical CJ curves for the P4SMA family, no value is tabulated for the 18V variants. For high-frequency signal line protection (e.g., CAN bus), designers should select TVS devices with published CJ specs (e.g., <100pF) - P4SMA18CH is intended for power rail, not data line, protection.
P4SMA18CH 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:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 14.5V
- Voltage - Breakdown (Min):
- 16.2V
- Voltage - Clamping (Max) @ Ipp:
- 26.5V
- Current - Peak Pulse (10/1000µs):
- 16A
- 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)
P4SMA18CH FAQ
1.How can I place an order for P4SMA18CH through Aetrix?
Please submit a Request for Quotation (RFQ) for P4SMA18CH 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 P4SMA18CH reliable?
The price and inventory of P4SMA18CH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for P4SMA18CH is usually 5 days.
3.What payment methods are accepted for P4SMA18CH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for P4SMA18CH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for P4SMA18CH?
P4SMA18CH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your P4SMA18CH 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 P4SMA18CH?
For technical support, including P4SMA18CH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your P4SMA18CH requirements.
6.How does Aetrix verify that P4SMA18CH is sourced from the original manufacturer or authorized distributors?
All P4SMA18CH 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 P4SMA18CH meets industry standards.
7.What is the process for return or replacement of P4SMA18CH?
All P4SMA18CH units undergo pre-shipment inspection (PSI). If there is an issue with P4SMA18CH, 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 P4SMA18CH part is unused and in its original packaging.
Return procedure for P4SMA18CH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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