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Taiwan Semiconductor Corporation SA28A
- Part No.:
- SA28A
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-204AC, DO-15, Axial
- Datasheet:
-
SA28A.pdf
- Description:
- TVS DIODE 28VWM 59VC DO204AC
- Quantity:
- Payment:
- Shipping:
Inventory:5,389
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Product details
Overview
SA28A from Taiwan Semiconductor is a unidirectional transient voltage suppressor (TVS) diode in DO-204AC (DO-15) package, rated for 500W peak pulse power at 10/1000μs, with 28V working stand-off voltage, 31.1–34.4V breakdown voltage at 1mA test current, and 59.0V maximum clamping voltage at 11.5A peak pulse current-designed for automotive ESD and inductive load protection.
For engineers reviewing the SA28A datasheet, SA28A pinout, SA28A application, or SA28A equivalent, key selection criteria include clamping performance under 10/1000μs surge, unidirectional polarity marking, AEC-Q101 qualification status, thermal derating above 25°C, and compatibility with lead-free reflow per J-STD-002.
Technical Context
The SA28A operates as a silicon avalanche diode that enters controlled breakdown when reverse voltage exceeds VBR (31.1–34.4V), limiting transient energy to protected circuitry via low-impedance conduction. Its unidirectional configuration provides forward conduction path only during positive surges on the anode side relative to cathode.
It delivers 500W peak pulse power handling per 10/1000μs waveform, with <1.0ps response time from 0V to VBR, <1μA reverse leakage at 28V, and junction temperature range of –55°C to +175°C-enabling robust operation in automotive under-hood and industrial control environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 28 V - Maximum continuous reverse operating voltage before significant leakage begins |
| VBR @ IT=1mA | 31.1–34.4 V - Breakdown voltage range defining reliable avalanche onset threshold |
| VC @ IPPM=11.5A | 59.0 V - Clamping voltage limiting downstream circuit stress during full-rated surge |
| PPK | 500 W - Peak pulse power dissipation capability per 10/1000μs waveform |
| IR @ VWM | <1 μA - Low leakage ensures minimal standby power loss and signal integrity |
| TJ max | +175 °C - Enables placement near high-temperature components without thermal derating penalties |
| Package | DO-204AC (DO-15) - Industry-standard axial-leaded package with tin-plated leads, UL 94V-0 molding |
Pinout & Package
DO-204AC (DO-15) axial-leaded package with cathode band marking; leads are pure tin plated and solderable per J-STD-002. Polarity is marked by a single band indicating cathode terminal.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Surge return path / low-side connection | Connected to ground or low-impedance reference; conducts during reverse transients |
| Cathode | Protected line input / high-side connection | Marked with band; connects to line being protected; blocks normal operation up to VWM |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified variant available | Validated for automotive applications including engine control, body electronics, and infotainment power rails |
| Fast response time <1.0ps | Enables suppression of nanosecond-scale ESD events before sensitive ICs experience overstress |
| Low impedance surge resistance | Minimizes voltage overshoot during high-di/dt transients such as relay coil de-energization |
| RoHS and halogen-free compliance | Meets IEC 61249-2-21 and environmental requirements for global OEM production |
| 175°C maximum junction temperature | Supports operation in high-ambient environments like automotive power distribution modules |
Applications
| Automotive Power Line Protection | Industrial Relay Coil Suppression |
|---|---|
Use Scenario: Protecting 12V/24V power supply inputs in vehicle ECUs against load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery rail and regulator input to clamp transients before LDO or DC-DC stage. Use Value: Limits clamped voltage to 59.0V at 11.5A, preventing overvoltage damage to downstream PMICs and microcontrollers. | Use Scenario: Suppressing back-EMF spikes generated by 24V solenoid valves in factory automation PLC I/O modules. IC Role / Device Role / Timing Role: Mounted across relay coil terminals to absorb inductive energy within sub-microsecond timescale. Use Value: Fast <1.0ps response ensures clamping initiates before coil voltage exceeds 60V, avoiding MOSFET gate oxide failure. |
| LED Driver Overvoltage Protection | ESD-Sensitive Sensor Interface Protection |
Use Scenario: Safeguarding constant-current LED drivers in outdoor lighting against lightning-induced surges on AC mains input. IC Role / Device Role / Timing Role: Placed at primary-side rectifier output to limit transient voltage applied to driver IC's HV startup pin. Use Value: Withstands 500W surge energy while maintaining 28V stand-off, preserving driver functionality during repeated transients. | Use Scenario: Shielding CAN transceiver data lines and analog sensor inputs (e.g., temperature, pressure) from ESD events in automotive cabin modules. IC Role / Device Role / Timing Role: Used in conjunction with series resistors and filtering capacitors to form low-pass ESD protection network. Use Value: Sub-1μA leakage at 28V prevents signal offset errors in precision analog front-ends while enabling fast ESD clamping. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ28A | Same DO-214AC package; 28V VWM, 59.0V VC @ 11.5A, but lower PPK (400W) | Limited to lower-energy transients; not rated for full 500W 10/1000μs pulses | Select SMAJ28A only if system-level surge testing confirms ≤400W requirement and board space favors SMD layout |
| P6SMB28A | DO-214AA package; identical VWM/VC ratings but higher IR (≤5μA vs. ≤1μA) and no AEC-Q101 option | Higher leakage may affect low-power sensor bias networks; lacks automotive qualification path | Choose P6SMB28A for cost-sensitive industrial designs where AEC-Q101 is unnecessary and leakage tolerance >1μA |
Compared with SMAJ28A and P6SMB28A, the SA28A delivers full 500W surge rating in axial DO-15 form factor, sub-1μA leakage critical for precision analog circuits, and optional AEC-Q101 qualification-making it optimal for automotive power rail and high-reliability industrial protection where thermal margin and qualification matter.
Availability
SA28A is available at Aetrix Electronics and suitable for automotive power line protection, industrial relay coil suppression, LED driver overvoltage protection, and ESD-sensitive sensor interface protection requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SA28A 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 automotive-grade components since 1979.
The SA Series is designed specifically for high-energy transient suppression in automotive, industrial, and lighting systems-emphasizing AEC-Q101 qualification, wide VWM range (5–170V), and consistent 500W surge capability across all variants.
FAQ
What is the breakdown voltage range of the SA28A?
The SA28A has a specified breakdown voltage (VBR) range of 31.1 V to 34.4 V at 1 mA test current, measured per ANSI/IEEE C62.35 standards. This range ensures consistent avalanche initiation across production lots and supports reliable clamping behavior in automotive and industrial surge environments where precise voltage thresholds are critical for system-level protection coordination.
Is the SA28A unidirectional or bidirectional?
The SA28A is a unidirectional TVS diode, indicated by its "A" suffix and cathode band marking. It conducts only during reverse-biased transients-clamping positive surges on the cathode side-and blocks forward current beyond VF ≈ 3.5 V at 35 A. Bidirectional versions (e.g., SA28CA) are separate part numbers with symmetrical characteristics in both directions.
Does the SA28A meet AEC-Q101 requirements?
The SA28A itself is not automatically AEC-Q101 qualified; however, the SA28AH variant (with "H" suffix) is explicitly qualified per AEC-Q101 Rev D. The base SA28A shares identical electrical and mechanical specifications but lacks the full automotive qualification documentation and test reports required for automotive safety-critical applications.
What is the maximum clamping voltage of the SA28A at rated surge current?
The SA28A exhibits a maximum clamping voltage (VC) of 59.0 V at 11.5 A peak pulse current (IPPM), tested using the standard 10/1000 μs double-exponential waveform. This value defines the upper voltage limit imposed on protected circuitry during worst-case surge events and is critical for ensuring downstream ICs remain within absolute maximum ratings.
Can the SA28A be used in surface-mount designs?
No-the SA28A is packaged exclusively in the axial-leaded DO-204AC (DO-15) case and is not available in surface-mount formats. For SMD alternatives with comparable ratings, consider SMAJ28A (DO-214AC) or SMCJ28A (DO-214AB), which differ in package dimensions, thermal resistance, and mounting method but share similar electrical parameters.
SA28A 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:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 28V
- Voltage - Breakdown (Min):
- 31.1V
- Voltage - Clamping (Max) @ Ipp:
- 59V
- Current - Peak Pulse (10/1000µs):
- 11.5A
- 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)
SA28A FAQ
1.How can I place an order for SA28A through Aetrix?
Please submit a Request for Quotation (RFQ) for SA28A 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 SA28A reliable?
The price and inventory of SA28A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SA28A is usually 5 days.
3.What payment methods are accepted for SA28A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SA28A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SA28A?
SA28A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SA28A 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 SA28A?
For technical support, including SA28A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SA28A requirements.
6.How does Aetrix verify that SA28A is sourced from the original manufacturer or authorized distributors?
All SA28A 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 SA28A meets industry standards.
7.What is the process for return or replacement of SA28A?
All SA28A units undergo pre-shipment inspection (PSI). If there is an issue with SA28A, 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 SA28A part is unused and in its original packaging.
Return procedure for SA28A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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