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Taiwan Semiconductor Corporation SA18CH
- Part No.:
- SA18CH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-204AC, DO-15, Axial
- Datasheet:
-
SA18CH.pdf
- Description:
- 500W, 22.2V, BIDIRECTIONAL, TVS
- Quantity:
- Payment:
- Shipping:
Inventory:6,336
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Product details
Overview
SA18CH from Taiwan Semiconductor is a unidirectional 500W transient voltage suppressor (TVS) diode in DO-204AC (DO-15) package, with 18V working stand-off voltage (VWM), 20.0–24.4V breakdown voltage (VBR @ 1mA), and 32.2V maximum clamping voltage (VC) at 16.3A peak pulse current. It delivers AEC-Q101 qualification for automotive-grade surge immunity in power rail and signal line protection.
For engineers reviewing the SA18CH datasheet, SA18CH pinout, SA18CH application, or SA18CH equivalent, this device is selected for high-reliability DC power input protection, ESD-hardened sensor interfaces, and inductive load flyback suppression where fast clamping (<1.0ps response), low leakage (<1μA @ 18V), and 175°C junction temperature capability are critical.
Technical Context
The SA18CH operates as a unidirectional avalanche diode, triggered when reverse voltage exceeds its VBR range (20.0–24.4V). Its clamping action limits transients to ≤32.2V at 16.3A under 10/1000μs waveform, with thermal derating above 25°C per Fig.2 and non-repetitive surge handling up to 500W.
It features pure tin-plated leads compliant with J-STD-002, UL 94V-0 molding compound, and meets JESD201 Class 2 whisker resistance. Polarity is marked by cathode band; no internal series impedance or integrated filtering is present.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18 V - Maximum continuous reverse operating voltage before clamping begins |
| VBR min/max | 20.0 / 24.4 V @ 1 mA - Confirmed breakdown threshold range for reliable turn-on margin |
| VC @ IPPM | 32.2 V @ 16.3 A - Clamped voltage during 10/1000μs surge, defining protected circuit voltage ceiling |
| PPK | 500 W - Peak pulse power rating at TA = 25°C, derated linearly above ambient |
| IR @ VWM | <1 μA - Reverse leakage ensures minimal standby power loss and signal integrity |
| TJ max | +175 °C - Enables operation in under-hood automotive environments and high-power industrial enclosures |
| AEC-Q101 | Qualified - Validated for automotive electronics per stress test requirements (HTOL, TCT, etc.) |
Pinout & Package
DO-204AC (DO-15) axial-leaded package with cathode band marking 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 conduction terminal | Connected to lower-potential side (e.g., GND or return path) in unidirectional configuration |
| Cathode | Reverse-biased clamping terminal | Connected to protected line (e.g., 12V rail); clamps to anode when transient exceeds VBR |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive use including temperature cycling, high-temperature operating life, and mechanical shock |
| Fast response time | <1.0 ps from 0 V to VBR enables sub-nanosecond transient capture before IC damage occurs |
| Low clamping ratio | VC/VBR ≈ 1.43 (32.2V / 22.5V avg) - tight voltage control minimizes overvoltage stress on downstream components |
| RoHS & halogen-free | Complies with IEC 61249-2-21 and EU RoHS directives for environmentally constrained applications |
| 500W surge rating | Sustains 10/1000μs transients up to 16.3A without degradation, supporting ISO 7637-2 Pulse 1/2/5a compliance |
Applications
| Automotive Power Input Protection | Industrial Sensor Interface ESD Protection |
|---|---|
Use Scenario: 12V battery-fed ECUs exposed to load dump and jump-start surges per ISO 7637-2. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery rail and DC-DC input to clamp transients before regulator stage. Use Value: Limits voltage to ≤32.2V during 500W surges, preventing overvoltage failure of buck controller ICs and MOSFETs. | Use Scenario: Analog sensor outputs (e.g., pressure, temp) routed across PCBs with long traces susceptible to HBM/IEC 61000-4-2 ESD. IC Role / Device Role / Timing Role: Low-leakage (≤1μA) TVS shunting ESD energy to ground while preserving signal fidelity. Use Value: Sub-1ps response captures ESD events before op-amp input stages saturate or latch up. |
| Inductive Load Flyback Suppression | Lighting System Surge Immunity |
Use Scenario: Relay or solenoid drivers switching 24V inductive loads in factory automation PLCs. IC Role / Device Role / Timing Role: Unidirectional TVS across coil terminals to absorb flyback energy and protect driver MOSFETs. Use Value: Withstands 70A IFSM peak forward surge and clamps flyback spikes within safe SOA of logic-level gate drivers. | Use Scenario: LED driver inputs in streetlight controllers subjected to lightning-induced surges on AC mains lines. IC Role / Device Role / Timing Role: Primary-stage TVS on rectified DC bus to limit surge propagation into constant-current LED ICs. Use Value: 175°C TJ max allows mounting near heat-generating LED arrays without thermal derating penalties. |
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 | Same DO-214AC package; 18V VWM, but 20.0–22.1V VBR and 29.2V VC @ 17.1A - tighter VBR tolerance, lower clamping voltage | Preferred where lower clamping voltage is prioritized over AEC-Q101 qualification | Select SMAJ18A if automotive qualification is not required and clamping voltage margin is critical |
| P6SMB18AH | DO-214AA package; 18V VWM, 20.0–22.2V VBR, 29.2V VC @ 17.1A; AEC-Q101 qualified; higher thermal mass than DO-15 | Better thermal dissipation in high-duty-cycle surge environments due to larger package footprint | Select P6SMB18AH when board layout permits larger SMD footprint and enhanced thermal performance is needed |
Compared with SMAJ18A and P6SMB18AH, the SA18CH offers identical VWM and AEC-Q101 qualification in a legacy axial DO-15 package-ideal for through-hole manufacturing, repairability, and cost-sensitive automotive modules where leaded assembly remains standard.
Availability
SA18CH is available at Aetrix Electronics and suitable for automotive power input protection, industrial sensor interface ESD protection, and inductive load flyback suppression requiring stable component supply across production lifecycles.
Supply support for SA18CH 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 SA Series is designed specifically for high-energy transient suppression in automotive, industrial, and lighting systems-emphasizing AEC-Q101 reliability, tight parametric consistency, and robust surge handling in axial and surface-mount packages.
FAQ
What is the clamping voltage of SA18CH and how is it measured?
The SA18CH has a maximum clamping voltage (VC) of 32.2 V, measured at 16.3 A peak pulse current under the standardized 10/1000 μs double-exponential surge waveform. This value is guaranteed per the datasheet's electrical characteristics table and defines the upper voltage limit imposed on protected circuits during transient events. The SA18CH achieves this clamping performance while maintaining low dynamic impedance and sub-nanosecond response.
Is SA18CH unidirectional or bidirectional, and how is polarity identified?
The SA18CH is a unidirectional TVS diode, intended for DC rail protection where polarity is fixed. Polarity is identified by a cathode band marked on the DO-204AC (DO-15) package body - the banded end connects to the protected line (e.g., 12V), and the unbanded end connects to ground. Bidirectional variants in the SA series use "CA" suffixes (e.g., SA18CA), which the SA18CH does not carry.
Does SA18CH meet automotive qualification standards?
Yes, the "H" suffix in SA18CH explicitly denotes AEC-Q101 qualification per the manufacturer's ordering information. This includes testing for high-temperature operating life, temperature cycling, mechanical shock, and humidity bias. The SA18CH is rated for junction temperatures up to +175°C and is approved for use in engine control units, body electronics, and other automotive subsystems requiring validated reliability.
What is the maximum peak pulse current SA18CH can handle?
The SA18CH supports a maximum peak pulse current (IPPM) of 16.3 A under the 10/1000 μs waveform, corresponding to its 500 W peak pulse power rating at 25°C ambient. This rating is thermally derated above 25°C per the published pulse derating curve (Fig.2), and the device also withstands 70 A non-repetitive forward surge (IFSM) for 8.3 ms half-sine wave - critical for inductive load switching applications.
How does SA18CH compare to SA18A in terms of breakdown voltage and clamping performance?
The SA18CH has a VBR range of 20.0–24.4 V and VC of 32.2 V, whereas the SA18A variant has a tighter VBR of 20.0–22.1 V and lower VC of 39.4 V. The "H" suffix indicates AEC-Q101 qualification absent in SA18A. Thus, SA18CH provides broader VBR tolerance and superior clamping voltage, making it more robust for variable-temperature automotive environments where consistent clamping margin is essential.
SA18CH 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:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-204AC (DO-15)
SA18CH FAQ
1.How can I place an order for SA18CH through Aetrix?
Please submit a Request for Quotation (RFQ) for SA18CH 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 SA18CH reliable?
The price and inventory of SA18CH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SA18CH is usually 5 days.
3.What payment methods are accepted for SA18CH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SA18CH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SA18CH?
SA18CH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SA18CH 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 SA18CH?
For technical support, including SA18CH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SA18CH requirements.
6.How does Aetrix verify that SA18CH is sourced from the original manufacturer or authorized distributors?
All SA18CH 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 SA18CH meets industry standards.
7.What is the process for return or replacement of SA18CH?
All SA18CH units undergo pre-shipment inspection (PSI). If there is an issue with SA18CH, 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 SA18CH part is unused and in its original packaging.
Return procedure for SA18CH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SA18CH Tags
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