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onsemi SA12CA
- Part No.:
- SA12CA
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-204AC, DO-15, Axial
- Datasheet:
-
SA12CA.pdf
- Description:
- TVS DIODE 12VWM 19.9VC DO15
- Quantity:
- Payment:
- Shipping:
Inventory:9,553
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Product details
Overview
SA12CA from Fairchild Semiconductor is a bidirectional 500 W transient voltage suppressor (TVS) diode designed for surge protection in DC power lines and signal interfaces. It features a 12 V reverse stand-off voltage (VRWM), 13.3–14.7 V breakdown voltage (VBR) at 1.0 mA, 19.9 V clamping voltage (VC) at 25.1 A peak pulse current (IPPM), and operates up to +175 °C junction temperature - used in industrial power supplies and telecom interface protection.
For engineers reviewing the SA12CA datasheet, pinout, applications, or equivalent options, key selection criteria include bidirectional clamping capability, DO-15 package compatibility, low incremental surge resistance, sub-5 ns response time, and compliance with IEC 61000-4-2/4-5 surge immunity standards.
Technical Context
The SA12CA employs a glass-passivated junction for stable avalanche performance and low leakage (<1 µA at VRWM). Its bidirectional structure enables symmetrical clamping in both polarities without external polarity management, making it suitable for AC-coupled or floating signal paths.
It delivers 500 W peak pulse power on the standardized 10/1000 µs waveform, with clamping voltage tightly controlled at 19.9 V under 25.1 A transient stress - enabling robust overvoltage protection while preserving downstream component voltage margins.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power (10/1000 µs) | 500 W - sustains single high-energy surges per IEC 61000-4-5 Level 4 without failure |
| Reverse Stand-off Voltage (VRWM) | 12 V - maximum continuous operating voltage before significant leakage begins |
| Breakdown Voltage (VBR) | 13.3–14.7 V @ 1.0 mA - defines onset of controlled avalanche conduction |
| Clamping Voltage (VC) | 19.9 V @ 25.1 A - limits transient voltage seen by protected circuitry during surge |
| Peak Pulse Current (IPPM) | 25.1 A - maximum non-repetitive surge current the device safely clamps |
| Junction Temperature Range | +175 °C max - supports operation in high-ambient industrial or automotive under-hood environments |
| Response Time | <5.0 ns - ensures clamping activation before transient energy damages sensitive ICs |
Pinout & Package
SA12CA is housed in a DO-15 axial leaded package with no cathode band - consistent with bidirectional TVS construction. Leads are 0.375" long for standard PCB through-hole mounting and thermal dissipation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Surge current entry (positive polarity) | One terminal of symmetrical avalanche junction; interchangeable with cathode in bidirectional operation |
| Cathode | Surge current entry (negative polarity) | Second terminal of symmetrical junction; functionally identical to anode for clamping in either direction |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable, repeatable avalanche characteristics and long-term reliability under repeated surge stress |
| 500 W peak pulse rating (10/1000 µs) | Meets IEC 61000-4-5 surge immunity requirements for industrial equipment up to Level 4 |
| <5.0 ns response time (bidirectional) | Activates fast enough to protect CMOS inputs, RS-485 transceivers, and microcontroller I/O pins |
| Low incremental surge resistance | Minimizes voltage overshoot during high di/dt events, improving clamping precision |
| Reverse leakage <1 µA @ VRWM | Prevents excessive standby power loss in battery-backed or low-power systems |
Applications
| Industrial Power Input Protection | Telecom Line Interface |
|---|---|
Use Scenario: 24 V DC input stage of PLC I/O module exposed to inductive switching transients and lightning-induced surges. IC Role / Device Role / Timing Role: Primary overvoltage clamp placed across input terminals ahead of EMI filter and DC-DC converter. Use Value: Limits transient voltage to ≤19.9 V, preventing damage to upstream rectifier and downstream regulator ICs rated for 36 V max input. |
Use Scenario: RS-485 data line pair (A/B) in outdoor base station equipment subject to ESD and induced surges. IC Role / Device Role / Timing Role: Bidirectional TVS connected between differential pair and ground to shunt common-mode transients. Use Value: Symmetrical clamping preserves signal integrity while suppressing ±15 kV contact ESD (IEC 61000-4-2) without polarity biasing. |
| Automotive Body Control Module | AC-DC Adapter Surge Suppression |
Use Scenario: 12 V supply rail in BCM subjected to load dump (ISO 7637-2 Pulse 5a) and jump-start transients. IC Role / Device Role / Timing Role: Secondary protection device downstream of primary fuse and upstream of LDO regulators. Use Value: Withstands 500 W pulses up to 100 ms duration, clamping load dump peaks to safe levels for 3.3 V/5 V logic rails. |
Use Scenario: Input stage of universal AC-DC wall adapter handling 100–240 VAC mains with surge susceptibility. IC Role / Device Role / Timing Role: Across-line TVS on secondary-side DC output to absorb reflected surges from primary-side MOV failure. Use Value: 19.9 V clamping prevents overvoltage shutdown of USB-PD controller ICs and maintains regulation stability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ12CA | Same VRWM (12 V) and bidirectional configuration, but SMB package (surface-mount); 600 W rating; lower IPPM (32.3 A) | Better suited for automated SMT assembly; requires PCB layout revision due to different footprint and thermal path | Select when board space is constrained and reflow compatibility is required over through-hole serviceability |
| P6KE12CA | Same DO-15 package and 12 V VRWM, but lower 600 W rating and higher VC (20.1 V); larger junction capacitance (~1000 pF) | Higher clamping voltage reduces margin for low-voltage ICs; higher capacitance may degrade high-speed signal integrity | Acceptable for cost-sensitive industrial controls where 0.2 V clamping difference and bandwidth impact are negligible |
Compared with SMBJ12CA and P6KE12CA, the SA12CA offers optimal balance of through-hole manufacturability, 19.9 V clamping precision, and proven DO-15 thermal performance in legacy power designs - especially where mechanical robustness and serviceability are prioritized.
Availability
SA12CA is available at Aetrix Electronics and suitable for industrial power supplies, telecom interface protection, automotive body control modules, and AC-DC adapter surge suppression requiring stable component supply and long-term obsolescence management.
Supply support for SA12CA 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
Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016; its legacy TVS portfolio remains widely deployed and supported.
The SA12CA belongs to Fairchild's SAxxCA family of 500 W bidirectional TVS diodes, engineered specifically for high-reliability surge protection in harsh industrial and transportation environments where DO-15 mechanical ruggedness and predictable clamping are critical.
FAQ
What is the clamping voltage of SA12CA at its rated peak pulse current?
The SA12CA has a maximum clamping voltage (VC) of 19.9 V when subjected to its rated peak pulse current of 25.1 A on the 10/1000 µs waveform. This value is measured per JEDEC standards and ensures predictable voltage limiting during surge events. The SA12CA maintains this clamping performance across its full operating temperature range up to +175 °C junction temperature.
Is SA12CA unidirectional or bidirectional, and how does that affect circuit placement?
The SA12CA is a bidirectional TVS diode, indicated by the "CA" suffix, meaning it provides symmetrical clamping for both positive and negative transients without polarity sensitivity. Unlike unidirectional devices, it requires no cathode orientation during placement - simplifying layout and eliminating risk of reverse installation. This makes the SA12CA ideal for AC lines, differential data pairs, and floating power rails.
What package type does SA12CA use, and what are its mechanical dimensions?
The SA12CA uses the industry-standard DO-15 axial leaded package with 0.375" (9.5 mm) lead length, 2.54 mm lead spacing, and overall body diameter of approximately 3.6 mm. Its through-hole construction provides robust mechanical attachment and superior thermal dissipation compared to surface-mount alternatives - a key advantage in high-surge industrial applications where vibration and thermal cycling are concerns.
How does SA12CA compare to SA12A in terms of electrical behavior?
The SA12CA is the bidirectional version of the SA12A, which is unidirectional. While both share identical VRWM (12 V), VBR (13.3–14.7 V), and VC (19.9 V) ratings, the SA12CA clamps surges of either polarity, whereas the SA12A only protects against reverse-polarity transients and requires correct cathode orientation. Their DO-15 packages are mechanically identical, but SA12A features a visible cathode band - absent on SA12CA.
Does SA12CA meet international surge immunity standards such as IEC 61000-4-5?
Yes, the SA12CA's 500 W peak pulse power rating on the 10/1000 µs waveform directly supports compliance with IEC 61000-4-5 Level 4 (4 kV line-to-earth, 2 kV line-to-line) when properly implemented with appropriate series impedance. Its <5.0 ns response time and low clamping voltage ensure effective energy diversion before protected ICs experience overstress - a requirement verified in Fairchild's application notes for industrial power and communication interfaces.
SA12CA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-204AC, DO-15, Axial
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 12V
- Voltage - Breakdown (Min):
- 13.3V
- Voltage - Clamping (Max) @ Ipp:
- 19.9V
- Current - Peak Pulse (10/1000µs):
- 25.1A
- Power - Peak Pulse:
- 500W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-15
SA12CA FAQ
1.How can I place an order for SA12CA through Aetrix?
Please submit a Request for Quotation (RFQ) for SA12CA 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 SA12CA reliable?
The price and inventory of SA12CA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SA12CA is usually 5 days.
3.What payment methods are accepted for SA12CA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SA12CA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SA12CA?
SA12CA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SA12CA 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 SA12CA?
For technical support, including SA12CA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SA12CA requirements.
6.How does Aetrix verify that SA12CA is sourced from the original manufacturer or authorized distributors?
All SA12CA 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 SA12CA meets industry standards.
7.What is the process for return or replacement of SA12CA?
All SA12CA units undergo pre-shipment inspection (PSI). If there is an issue with SA12CA, 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 SA12CA part is unused and in its original packaging.
Return procedure for SA12CA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SA12CA Tags
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ESD9B5.0ST5G
onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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onsemi
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D5V0H1B2LP-7B
Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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ESD5Z5.0T1G
onsemi
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DESD5V0U1BB-7
Diodes Incorporated
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Diodes Incorporated
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PESD2V0Y1BSFYL
Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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D5V0L1B2WS-7
Diodes Incorporated
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