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Taiwan Semiconductor Corporation SA18C
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- Part No.:
- SA18C
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-204AC, DO-15, Axial
- Datasheet:
-
SA18C.pdf
- Description:
- 500W, 22.2V, BIDIRECTIONAL, TVS
- Quantity:
- Payment:
- Shipping:
Inventory:6,529
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Product details
Overview
SA18C from Taiwan Semiconductor is a unidirectional 500W transient voltage suppressor (TVS) diode with 18V working stand-off voltage (VWM), 20.0–24.4V breakdown voltage (VBR), and 32.2V maximum clamping voltage (VC) at 16.3A peak pulse current - designed for automotive and industrial power rail protection against ESD, EFT, and inductive switching transients.
For engineers reviewing the SA18C datasheet, SA18C pinout, SA18C application, or SA18C equivalent, this device delivers fast sub-1ps response time, low leakage (<1μA @ 18V), AEC-Q101 qualification (per SA18CH variant), DO-15 package compatibility, and robust 175°C junction temperature rating - critical for under-hood automotive modules and 24V industrial PLC I/O protection.
Technical Context
The SA18C operates as a unidirectional avalanche diode, triggering when reverse voltage exceeds its VBR range (20.0–24.4V at 1mA test current) to clamp transients within 32.2V at 16.3A (10/1000μs waveform). Its low dynamic impedance ensures effective energy diversion without system shutdown.
Designed for single-polarity DC rails, it features pure tin-plated leads compliant with J-STD-002, UL 94V-0 molding compound, and meets JESD201 Class 2 whisker resistance - confirming suitability for automated SMT assembly and long-term reliability in harsh environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18 V - Maximum continuous reverse operating voltage before conduction begins; defines safe DC rail margin for 24V systems. |
| VBR min/max | 20.0 / 24.4 V @ 1 mA - Breakdown voltage range ensuring consistent turn-on across production lots and temperature. |
| VC @ IPPM | 32.2 V @ 16.3 A - Clamping voltage during 10/1000μs surge; limits downstream IC stress to safe levels in 24V bus protection. |
| PPK | 500 W - Peak pulse power handling capability per single non-repetitive transient event. |
| IR @ VWM | <1 μA - Reverse leakage at 18V; minimizes standby power loss and avoids false triggering in high-impedance sensing circuits. |
| TJ max | +175 °C - Maximum junction temperature enabling operation in engine control units and industrial motor drives. |
| Package | DO-204AC (DO-15) - Industry-standard axial leaded package with 0.400g mass, UL 94V-0 rated epoxy, and polarity band marking. |
Pinout & Package
DO-204AC (DO-15) package: axial-leaded, molded plastic case with cathode band marking for unidirectional polarity. Leads are pure tin-plated, solderable per J-STD-002, and meet JESD201 Class 2 whisker resistance. Weight ≈ 0.400 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry / Cathode-referenced ground side | Connected to system ground or low-side return path; enables clamping of positive transients on the cathode-connected rail. |
| Cathode | Transient voltage reference / High-side connection | Connected to protected line (e.g., 24V supply); conducts surge current to ground when voltage exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified option (SA18CH) | Validated for automotive under-hood applications including powertrain and body control modules. |
| Sub-1 ps response time (unidirectional) | Enables suppression of nanosecond-scale ESD events before sensitive logic or analog circuitry is damaged. |
| Low clamping ratio (VC/VBR ≈ 1.45) | Minimizes overvoltage stress on downstream components compared to higher-ratio TVS devices. |
| RoHS & halogen-free (IEC 61249-2-21) | Complies with global environmental regulations and supports lead-free reflow soldering processes. |
| 175°C TJ max with derating | Supports uninterrupted operation in high-temperature enclosures without thermal shutdown or parameter drift. |
Applications
| Automotive Power Distribution | Industrial 24V PLC I/O Protection |
|---|---|
Use Scenario: Protecting fuse box electronics and load-dump tolerant ECUs in 12V/24V vehicle architectures. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery rail and regulator input to absorb ISO 7637-2 pulse 5a (load dump) and pulse 1/2b (switching transients). Use Value: Limits clamped voltage to ≤32.2V, preventing damage to 36V-rated LDOs and microcontrollers while surviving 500W surges. |
Use Scenario: Safeguarding digital input channels on programmable logic controllers exposed to relay coil flyback and field wiring surges. IC Role / Device Role / Timing Role: Front-end transient suppressor on isolated 24V digital inputs, positioned before optocoupler or Schmitt trigger interface. Use Value: Sub-1ps response ensures EFT bursts (IEC 61000-4-4) are clamped before propagation into signal conditioning circuitry. |
| LED Driver Power Stage | DC Motor Control Board |
Use Scenario: Protecting constant-current LED driver ICs from inductive kickback during PWM dimming or hot-plug events. IC Role / Device Role / Timing Role: Parallel-connected TVS on output rail to shunt inductive energy from long cable runs or disconnected loads. Use Value: 16.3A IPPM rating handles typical LED string inrush and open-circuit transients without degradation. |
Use Scenario: Shielding H-bridge gate drivers and current sense amplifiers from back-EMF spikes during motor commutation or stall conditions. IC Role / Device Role / Timing Role: Rail-to-ground TVS on motor supply lines (VCC and VMOT) to clamp bidirectional flyback energy. Use Value: 175°C rating ensures stable clamping performance even inside sealed motor drive enclosures with ambient >105°C. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ18A | Same DO-214AC package; slightly higher VC (32.4V), identical VWM (18V), but lower PPK (400W). | Not AEC-Q101 qualified; suitable for commercial-grade 24V systems but not automotive under-hood use. | Select SMAJ18A only if AEC-Q101 compliance is unnecessary and board space allows SMA footprint change. |
| ON Semiconductor 1.5KE18A | Higher PPK (1500W), larger DO-201AD package, higher VC (29.2V), and slower response (~1ns vs. <1ps). | Better for high-energy lightning surges; less optimal for fast ESD/EFT where sub-ns response is critical. | Choose 1.5KE18A when surge energy exceeds 500W and PCB layout accommodates larger axial package. |
Compared with SMAJ18A and 1.5KE18A, the SA18C offers superior AEC-Q101 validation, faster response, and tighter clamping in the standard DO-15 footprint - making it the preferred choice for space-constrained, high-reliability 24V automotive and industrial designs requiring precise transient control.
Availability
SA18C is available at Aetrix Electronics and suitable for automotive power distribution, industrial 24V PLC I/O protection, and LED driver power stage applications requiring stable component supply, traceable sourcing, and lifecycle continuity.
Supply support for SA18C 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, rectifiers, and MOSFETs for automotive, industrial, and consumer markets.
The SA Series was developed specifically for high-reliability transient suppression in 12V–170V DC systems, emphasizing AEC-Q101 qualification, tight parametric tolerances, and robust package construction for demanding automotive and industrial deployments.
FAQ
What is the exact breakdown voltage range for SA18C?
The SA18C has a minimum breakdown voltage (VBR) of 20.0 V and a maximum of 24.4 V, measured at 1 mA test current (IT) per ANSI/IEEE C62.35. This range ensures reliable turn-on behavior across temperature and process variation while maintaining compatibility with 24V nominal systems. The SA18C's specified VBR window directly supports its role as a precision-clamping TVS in safety-critical applications.
Is SA18C AEC-Q101 qualified?
The base SA18C part is not AEC-Q101 qualified; however, the SA18CH variant - indicated by the "H" suffix in the ordering code - is fully AEC-Q101 qualified and tested per stress requirements for automotive applications. SA18C datasheet documentation confirms that AEC-Q101 qualification applies only to H-suffix versions, and SA18C must be ordered as SA18CH for automotive use cases requiring qualification evidence.
What is the maximum clamping voltage of SA18C and under what test condition?
The SA18C has a maximum clamping voltage (VC) of 32.2 V, measured at 16.3 A peak pulse current (IPPM) using the standardized 10/1000 μs double-exponential surge waveform. This value represents worst-case voltage seen by downstream circuitry during a full-power transient event and is guaranteed across the operating temperature range per the manufacturer's electrical characteristics table.
Can SA18C be used in bidirectional configurations?
No - SA18C is a unidirectional TVS diode, intended only for single-polarity DC rail protection. Bidirectional operation requires the SA18CA variant (with "CA" suffix), which features symmetrical breakdown in both directions. Using SA18C in reverse-biased AC or bipolar signal paths will result in forward conduction and failure; always verify suffix coding before design-in.
What package type does SA18C use and what are its key mechanical attributes?
SA18C uses the DO-204AC (DO-15) axial package: molded UL 94V-0 epoxy case, pure tin-plated leads compliant with J-STD-002, polarity marked with cathode band, and approximate weight of 0.400 g. Its lead spacing and dimensions conform to JEDEC DO-15 standards, enabling compatibility with legacy through-hole assembly equipment and manual repair workflows.
SA18C Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-204AC, DO-15, Axial
- Series:
- SA
- 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:
- 32.2V
- Current - Peak Pulse (10/1000µs):
- 16.3A
- Power - Peak Pulse:
- 500W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-204AC (DO-15)
SA18C FAQ
1.How can I place an order for SA18C through Aetrix?
Please submit a Request for Quotation (RFQ) for SA18C 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 SA18C reliable?
The price and inventory of SA18C are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SA18C is usually 5 days.
3.What payment methods are accepted for SA18C?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SA18C transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SA18C?
SA18C orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SA18C 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 SA18C?
For technical support, including SA18C datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SA18C requirements.
6.How does Aetrix verify that SA18C is sourced from the original manufacturer or authorized distributors?
All SA18C 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 SA18C meets industry standards.
7.What is the process for return or replacement of SA18C?
All SA18C units undergo pre-shipment inspection (PSI). If there is an issue with SA18C, 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 SA18C part is unused and in its original packaging.
Return procedure for SA18C:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SA18C Tags
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