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onsemi SA20CA
- Part No.:
- SA20CA
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-204AC, DO-15, Axial
- Datasheet:
-
SA20CA.pdf
- Description:
- TVS DIODE 20VWM 32.4VC DO15
- Quantity:
- Payment:
- Shipping:
Inventory:7,012
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Product details
Overview
SA20CA from Fairchild Semiconductor is a bidirectional 500 W transient voltage suppressor (TVS) diode in DO-15 package, with 20 V reverse stand-off voltage (VRWM), 22.2–24.5 V breakdown voltage (VBR), 32.4 V clamping voltage at 15.4 A peak pulse current, and <1 μA reverse leakage above 10 V. It protects DC power rails and data lines against ESD, lightning surges, and inductive switching transients in industrial control interfaces.
For engineers reviewing the SA20CA datasheet, pinout, applications, or equivalent options, key selection criteria include bidirectional clamping capability, 10/1000 μs waveform pulse rating, DO-15 thermal derating behavior, junction temperature limit of +175°C, and low incremental surge resistance for robust overvoltage immunity.
Technical Context
The SA20CA uses a glass-passivated junction to achieve fast response time (<5.0 ns for bidirectional operation) and stable clamping performance across temperature. Its unidirectional counterpart is SA20A; the "C" suffix explicitly denotes bidirectional symmetry, meaning electrical characteristics apply identically in both directions.
Designed for surge protection in bipolar signal paths and AC-coupled interfaces, it operates with no polarity sensitivity and maintains consistent VBR min/max (22.2 V / 24.5 V) and VC (32.4 V) under 10/1000 μs pulses. The device sustains non-repetitive forward surge current up to 70 A (8.3 ms half-sine) and operates up to +175°C junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 500 W on 10/1000 μs waveform - defines maximum single-event surge energy absorption without failure |
| Reverse Stand-off Voltage | 20 V - maximum continuous DC or RMS voltage before significant leakage begins |
| Breakdown Voltage | 22.2–24.5 V at 1.0 mA - onset of avalanche conduction; tight tolerance supports predictable trigger margin |
| Clamping Voltage | 32.4 V at 15.4 A IPPM - limits downstream circuit voltage during surge, enabling safe IC-level protection |
| Reverse Leakage | <1 μA at VRWM - ensures minimal standby power loss and signal integrity in high-impedance circuits |
| Junction Temperature | +175°C - enables reliable operation in enclosed industrial enclosures or near heat sources |
| Package | DO-15 - industry-standard axial leaded package with 0.375" lead length, rated for 1.0 W steady-state dissipation at 75°C ambient |
Pinout & Package
SA20CA is a two-terminal bidirectional TVS diode in DO-15 package. No color band is used - unlike unidirectional variants, bidirectional devices lack cathode marking as both terminals are functionally symmetric.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode / Cathode (symmetrical) | Surge current path | Either terminal accepts transient current in either direction; no polarity dependency in layout or connection |
| Leads (axial) | Thermal and mechanical interface | 0.375" lead length required for 1.0 W steady-state power dissipation rating at TA = 75°C |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Enables stable long-term reliability and low parameter drift under repeated surge stress |
| Fast response time | <5.0 ns turn-on - ensures clamping activation before sensitive downstream logic or analog circuitry is damaged |
| Bidirectional symmetry | Identical VBR, VC, and IR in both directions - eliminates need for polarity-aware routing in AC or differential lines |
| Low incremental surge resistance | Supports sharp voltage limiting under high di/dt events, reducing overshoot beyond clamping level |
Applications
| Industrial PLC I/O Protection | RS-485 Transceiver Protection |
|---|---|
Use Scenario: Protecting 24 V DC digital input modules in programmable logic controllers against field-wiring induced surges and ground loop transients. IC Role / Device Role: Primary bidirectional clamping element placed between signal line and ground, shunting surge energy before reaching optocoupler or microcontroller input. Use Value: With 32.4 V clamping and 500 W peak rating, SA20CA holds line voltage below 33 V during 1 kV/500 A surge events per IEC 61000-4-5, preserving input stage integrity. | Use Scenario: Safeguarding RS-485 transceivers (e.g., MAX1487, SN65HVD72) connected to long cable runs exposed to lightning-induced common-mode transients. IC Role / Device Role: Bidirectional TVS placed across A/B differential pair and from each line to ground, suppressing ±15 kV ESD (IEC 61000-4-2) and 10/700 μs telecom surges. Use Value: Symmetric 20 V VRWM aligns with RS-485 common-mode range (−7 V to +12 V); clamping at 32.4 V prevents transceiver damage while maintaining bus interoperability. |
| AC-DC Adapter Input Stage | Automotive Body Control Module (BCM) LIN Bus |
Use Scenario: Secondary-side transient suppression on 12–24 V DC outputs of switch-mode power supplies subject to load-dump or back-EMF coupling. IC Role / Device Role: Parallel-connected TVS across output rail to clamp overvoltage spikes caused by transformer leakage or regulator instability. Use Value: 20 V VRWM allows normal regulation headroom; 500 W rating handles multi-millisecond surges typical of capacitive discharge into supply rails. | Use Scenario: Protecting LIN transceivers in automotive body electronics against battery transients (ISO 7637-2 Pulse 1/2a/3a) and ESD in door modules or seat controls. IC Role / Device Role: Bidirectional clamping device placed between LIN bus line and chassis ground, referenced to 12 V battery system. Use Value: 22.2–24.5 V VBR ensures triggering only during actual overvoltage events (>20 V), avoiding false trips during normal battery ripple or cold-crank dips. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ20CA | DO-214AA (SMB) package; same 20 V VRWM, 32.4 V VC, but 600 W peak pulse rating | Higher power density; requires surface-mount PCB layout; lower thermal resistance than DO-15 | Select when board space is constrained and higher surge repetition rate is needed |
| P6SMB20CA | Same SMB package and 600 W rating; tighter VBR tolerance (22.2–24.5 V vs. 22.2–24.5 V), identical clamping | Manufactured by ON Semiconductor; RoHS-compliant with halogen-free option available | Choose for supply chain diversification or compliance-driven BOM requirements |
Compared with SMBJ20CA and P6SMB20CA, SA20CA offers proven axial-leaded reliability and simplified through-hole assembly, making it preferred for serviceable industrial equipment and legacy designs where manual rework or field replacement is routine - though its 500 W rating and DO-15 thermal profile require larger copper areas for sustained surge duty.
Availability
SA20CA is available at Aetrix Electronics and suitable for industrial PLC I/O protection, RS-485 communication interfaces, AC-DC adapter output stages, and automotive LIN bus systems requiring stable component supply and long-lifecycle support.
Supply support for SA20CA 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, signal conditioning, and discrete components before its acquisition by ON Semiconductor in 2016. Its TVS portfolio emphasized ruggedness and consistency for industrial and automotive applications.
The SAxxCA series was developed specifically for cost-sensitive, high-reliability bipolar surge protection in harsh environments - targeting applications where bidirectional clamping, DO-15 mechanical robustness, and 175°C junction operation were mandatory design requirements.
FAQ
What is the clamping voltage of SA20CA at its rated peak pulse current?
The SA20CA has a maximum clamping voltage (VC) of 32.4 V when subjected to its rated peak pulse current (IPPM) of 15.4 A on a 10/1000 μs waveform. This value is measured per JEDEC standards and guarantees that downstream circuitry will not experience voltages exceeding 32.4 V during specified surge events. The SA20CA's clamping performance is repeatable and validated across temperature and production lots.
Is SA20CA unidirectional or bidirectional, and how does that affect circuit placement?
SA20CA is a bidirectional TVS diode, indicated by the "C" suffix. Unlike unidirectional types (e.g., SA20A), it provides symmetrical clamping in both polarities - meaning either terminal can serve as anode or cathode. This eliminates orientation constraints during PCB placement and makes SA20CA ideal for AC-coupled lines, differential buses like RS-485, or any application where voltage polarity reversal may occur. No color band is present on the DO-15 body.
What is the maximum operating junction temperature for SA20CA?
The SA20CA is rated for a maximum operating junction temperature (TJ) of +175°C. This specification allows deployment in high-ambient environments such as motor drive cabinets, power supply enclosures, or under-hood automotive locations. Thermal design must account for DO-15 lead length (0.375") and PCB copper area to maintain junction temperature within limit during steady-state and pulsed power conditions.
Does SA20CA meet industry-standard ESD and surge immunity requirements?
Yes, SA20CA is designed to support compliance with IEC 61000-4-2 (±15 kV air, ±8 kV contact discharge) and IEC 61000-4-5 (10/700 μs and 1.2/50 μs waveforms). Its 500 W peak pulse power rating on 10/1000 μs waveform, fast <5.0 ns response, and low clamping voltage enable effective protection for circuits targeting Level 4 ESD and Class III surge immunity. System-level validation is still required per end-equipment standards.
How does SA20CA differ from SA20A?
SA20CA is the bidirectional version; SA20A is unidirectional. Both share identical VRWM (20 V), VBR (22.2–24.5 V), and VC (32.4 V), but SA20A has a cathode band and conducts only in reverse bias - requiring correct polarity during placement. SA20CA has no polarity marking and clamps equally in both directions. Use SA20CA for AC, differential, or polarity-agnostic protection; use SA20A only when unidirectional blocking is required.
SA20CA 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):
- 20V
- Voltage - Breakdown (Min):
- 22.2V
- Voltage - Clamping (Max) @ Ipp:
- 32.4V
- Current - Peak Pulse (10/1000µs):
- 15.4A
- 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
SA20CA FAQ
1.How can I place an order for SA20CA through Aetrix?
Please submit a Request for Quotation (RFQ) for SA20CA 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 SA20CA reliable?
The price and inventory of SA20CA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SA20CA is usually 5 days.
3.What payment methods are accepted for SA20CA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SA20CA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SA20CA?
SA20CA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SA20CA 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 SA20CA?
For technical support, including SA20CA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SA20CA requirements.
6.How does Aetrix verify that SA20CA is sourced from the original manufacturer or authorized distributors?
All SA20CA 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 SA20CA meets industry standards.
7.What is the process for return or replacement of SA20CA?
All SA20CA units undergo pre-shipment inspection (PSI). If there is an issue with SA20CA, 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 SA20CA part is unused and in its original packaging.
Return procedure for SA20CA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SA20CA Tags
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onsemi
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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onsemi
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Diodes Incorporated
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Diodes Incorporated
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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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