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Taiwan Semiconductor Corporation SA51CA
- Part No.:
- SA51CA
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-204AC, DO-15, Axial
- Datasheet:
-
SA51CA.pdf
- Description:
- TVS DIODE 51VWM 82.4VC DO204AC
- Quantity:
- Payment:
- Shipping:
Inventory:5,203
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Product details
Overview
SA51CA from Taiwan Semiconductor is a bidirectional 500W transient voltage suppressor (TVS) diode in DO-204AC (DO-15) package, with 51V working stand-off voltage (VWM), 56.7–69.3V breakdown voltage (VBR), and 91.1V maximum clamping voltage (VC) at 5.7A peak pulse current - designed for ESD and electrical fast transient protection in automotive lighting and power supply input stages.
For engineers reviewing the SA51CA datasheet, SA51CA pinout, SA51CA application, or SA51CA equivalent, this device delivers verified bidirectional surge suppression with sub-5ns response time, <1μA reverse leakage above 10V, AEC-Q101 qualification option (H-suffix), and UL 94V-0 molding compound - critical for robustness in 12V/24V automotive subsystems and industrial I/O interfaces.
Technical Context
The SA51CA operates as a bidirectional avalanche diode, symmetrically clamping transients in both polarities without polarity dependence. Its VBR range (56.7–69.3V) and VC = 91.1V @ IPPM = 5.7A define its precise overvoltage threshold and energy-handling capability under 10/1000μs waveform.
It features low dynamic impedance during clamping, fast response (<5.0ns for bidirectional mode), and thermal stability up to TJ = +175°C. The DO-204AC package supports 70A non-repetitive forward surge current (IFSM) and meets JESD201 Class 2 whisker resistance and RoHS/halogen-free requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 51 V - Maximum continuous DC or RMS voltage the device blocks without clamping; sets system operating margin before protection activates. |
| VBR min/max | 56.7 / 69.3 V @ IT = 1 mA - Confirmed breakdown window ensures reliable turn-on across temperature and process variation. |
| VC @ IPPM | 91.1 V @ 5.7 A - Clamping voltage during 10/1000μs surge defines worst-case stress on downstream ICs. |
| PPK | 500 W - Peak pulse power rating per standard 10/1000μs waveform; determines single-event surge survivability. |
| IR @ VWM | <1 μA - Reverse leakage at 51V ensures negligible standby power loss and signal integrity in high-impedance circuits. |
| TJ max | +175 °C - Maximum junction temperature enables operation in under-hood automotive environments and sealed industrial enclosures. |
| Package | DO-204AC (DO-15) - Industry-standard axial leaded package with 0.400g mass, UL 94V-0 molding, and tin-plated leads compliant with J-STD-002. |
Pinout & Package
DO-204AC (DO-15) package: axial-leaded, cylindrical glass-passivated body with cathode band marking for unidirectional variants; SA51CA is bidirectional and has no polarity marking - terminals are electrically symmetrical.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Bidirectional surge path | Either terminal serves as anode or cathode depending on transient polarity; no orientation required in PCB layout. |
| Leads (L1/L2) | PCB interface & thermal conduction | 0.375" (9.5mm) lead length supports 3W steady-state dissipation when mounted on 10×10 mm copper pads. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC-coupled or floating lines (e.g., CAN bus, sensor differential pairs) without external polarity management. |
| <5.0 ns response time | Ensures clamping activation before transient energy couples into sensitive analog or digital circuitry - critical for EFT immunity (IEC 61000-4-4). |
| AEC-Q101 qualified variant available | SA51CAH version meets automotive-grade reliability for engine control, lighting, and body electronics applications requiring qualification evidence. |
| UL 94V-0 flammability rating | Molding compound prevents flame propagation during fault conditions - required for automotive and industrial safety compliance. |
| JESD201 Class 2 whisker resistance | Eliminates tin whisker growth risk in long-life deployments, supporting >15-year field reliability in telecom and transportation systems. |
Applications
| Automotive LED Headlamp Driver Input | Industrial PLC Digital Input Protection |
|---|---|
Use Scenario: Protects buck-boost LED driver ICs from load dump (ISO 7637-2 Pulse 5a) and jump-start surges in 12V/24V vehicle systems. IC Role / Device Role: Primary bidirectional TVS placed directly at connector entry point, shunting transients before filtering stage. Use Value: Withstands 500W pulses and clamps to ≤91.1V, keeping driver IC's absolute max input rating (typically 60–80V) within safe margin. |
Use Scenario: Shields 24V-rated optocoupler inputs on programmable logic controller modules from EFT bursts and inductive kickback from solenoid switching. IC Role / Device Role: Front-line transient absorber on dry-contact input channels, paired with series current-limiting resistor. Use Value: Sub-5ns response prevents latch-up in opto-ICs; <1μA leakage avoids false triggering in high-impedance sensing circuits. |
| USB-C Port ESD Protection | Smart Meter RS-485 Transceiver Interface |
Use Scenario: Guards USB-C CC and VCONN lines against ±15kV contact ESD (IEC 61000-4-2) in portable charging accessories and docking stations. IC Role / Device Role: Secondary-level TVS after common-mode choke, targeting differential and common-mode transients on low-voltage signaling lines. Use Value: 51V VWM allows safe operation across USB-C VCONN (up to 5V) and CC bias voltages while maintaining headroom for ESD overshoot. |
Use Scenario: Protects half-duplex RS-485 transceivers (e.g., SN65HVD7x) from lightning-induced surges on outdoor utility meter communication lines. IC Role / Device Role: Line-to-line and line-to-ground TVS on A/B bus pair, placed before common-mode choke and transceiver ESD diodes. Use Value: Bidirectional symmetry matches RS-485 differential signaling; 91.1V clamping preserves transceiver's ±12V common-mode range and prevents damage during 4kV surge events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ51CA (Bourns) | Same DO-214AA package (SMB), 51V VWM, 500W PPK, but 93.6V VC @ 5.6A; slightly higher clamping voltage and surface-mount form factor. | Requires PCB redesign for SMD placement; better suited for space-constrained consumer electronics vs. through-hole industrial modules. | Select SMBJ51CA only if board real estate is limited and reflow compatibility is prioritized over legacy through-hole assembly. |
| P6KE51CA (ON Semiconductor) | DO-204AC package identical to SA51CA, same 51V VWM and 500W rating, but 93.6V VC @ 5.6A and higher IR (5μA @ VWM). | Valid drop-in replacement for cost-sensitive industrial designs where 2.5V higher clamping is acceptable and leakage tolerance >1μA exists. | Choose P6KE51CA when sourcing flexibility is needed and minor VC/IR trade-offs align with system margin analysis. |
Compared with SA51CA, SMBJ51CA offers SMD integration at the cost of higher clamping and layout change, while P6KE51CA provides identical through-hole fit with relaxed leakage and clamping specs - making SA51CA optimal for AEC-Q101-ready designs needing lowest VC and tightest IR.
Availability
SA51CA is available at Aetrix Electronics and suitable for automotive lighting systems, industrial PLC input modules, USB-C accessory protection, and smart meter RS-485 interfaces requiring stable component supply and long-term lifecycle assurance.
Supply support for SA51CA 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 - headquartered in Hsinchu, Taiwan, with ISO/TS 16949 and AEC-Q200 certified production lines.
The SA Series was developed specifically for high-reliability transient suppression in automotive and industrial environments, emphasizing AEC-Q101 qualification readiness, tight parameter distribution, and robust package construction for harsh thermal and mechanical conditions.
FAQ
What is the key difference between SA51CA and SA51A?
The SA51CA is a bidirectional TVS diode, meaning it clamps transients equally in both polarities - ideal for AC lines, differential buses, or floating nodes. In contrast, SA51A is unidirectional and requires correct polarity orientation during placement. SA51CA has no cathode band marking, while SA51A does. Both share identical VWM (51V), VBR (56.7–69.3V), and PPK (500W), but SA51CA's bidirectional behavior makes it functionally distinct in circuit design. SA51CA remains the preferred choice for RS-485, CAN, or transformer-coupled signal protection.
Does SA51CA meet AEC-Q101 qualification?
The base SA51CA part is not AEC-Q101 qualified; however, the SA51CAH variant - indicated by the "H" suffix in the ordering code - is fully AEC-Q101 qualified and tested per stress test conditions including HTSL, TCT, and ESD. SA51CAH shares identical electrical specs and DO-204AC packaging but adds automotive-grade reliability documentation and screening. For automotive applications requiring formal qualification evidence, SA51CAH must be specified - SA51CA alone does not carry that certification.
What is the maximum clamping voltage of SA51CA under standard surge conditions?
The maximum clamping voltage (VC) of SA51CA is 91.1 V when subjected to its rated peak pulse current (IPPM) of 5.7 A under the standard 10/1000μs double-exponential waveform. This value is measured at TA = 25°C and represents the worst-case voltage seen across protected circuitry during a full-power surge event. At lower currents (e.g., 1A), VC drops to approximately 70–75 V, providing tighter protection margins for smaller transients.
Can SA51CA be used in place of a unidirectional TVS like SA51A in a DC power rail?
Yes, SA51CA can replace SA51A on a DC power rail, but with important implications: it will clamp both positive overvoltage and negative-going transients (e.g., reverse battery connection or ground bounce), offering broader protection. However, its bidirectional structure results in ~2× higher junction capacitance than SA51A, which may affect high-frequency noise filtering. Also, SA51CA lacks polarity marking - so no orientation check is needed, simplifying assembly. System validation should confirm that negative clamping behavior does not interfere with upstream regulators or monitoring circuits.
What is the thermal derating behavior of SA51CA above 25°C ambient?
SA51CA's peak pulse power (PPK) is derated linearly above TA = 25°C per Figure 2 in the datasheet: at 75°C ambient, PPK drops to ~350W; at 125°C, it falls to ~175W. Steady-state power dissipation (PD) is rated at 3W at TL = 75°C with 0.375" lead length on 10×10 mm copper pads. Junction temperature must remain ≤175°C - so layout, copper area, and airflow must be validated for sustained surge duty cycles. Derating curves apply strictly to non-repetitive pulses; repetitive surges require additional thermal modeling.
SA51CA 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):
- 51V
- Voltage - Breakdown (Min):
- 56.7V
- Voltage - Clamping (Max) @ Ipp:
- 82.4V
- Current - Peak Pulse (10/1000µs):
- 6.3A
- 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)
SA51CA FAQ
1.How can I place an order for SA51CA through Aetrix?
Please submit a Request for Quotation (RFQ) for SA51CA 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 SA51CA reliable?
The price and inventory of SA51CA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SA51CA is usually 5 days.
3.What payment methods are accepted for SA51CA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SA51CA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SA51CA?
SA51CA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SA51CA 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 SA51CA?
For technical support, including SA51CA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SA51CA requirements.
6.How does Aetrix verify that SA51CA is sourced from the original manufacturer or authorized distributors?
All SA51CA 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 SA51CA meets industry standards.
7.What is the process for return or replacement of SA51CA?
All SA51CA units undergo pre-shipment inspection (PSI). If there is an issue with SA51CA, 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 SA51CA part is unused and in its original packaging.
Return procedure for SA51CA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SA51CA Tags
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