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onsemi SA45A
- Part No.:
- SA45A
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-204AC, DO-15, Axial
- Datasheet:
-
SA45A.pdf
- Description:
- TVS DIODE 45VWM 72.7VC DO15
- Quantity:
- Payment:
- Shipping:
Inventory:8,360
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Product details
Overview
SA45A from Fairchild Semiconductor is a unidirectional 500 W transient voltage suppressor (TVS) diode in DO-15 package, with 45 V reverse stand-off voltage (VRWM), 50.0–55.3 V breakdown voltage (VBR), 72.7 V clamping voltage (VC) at 6.9 A peak pulse current, and <1.0 μA reverse leakage above 10 V. It protects DC power rails and signal lines in industrial motor drives against ESD and lightning-induced surges.
For engineers reviewing the SA45A datasheet, pinout, applications, or equivalent options, key selection criteria include clamping performance under 10/1000 μs surge, junction temperature rating up to +175°C, unidirectional polarity for DC-biased protection, and DO-15 through-hole mounting compatibility with legacy PCB layouts.
Technical Context
The SA45A employs a glass-passivated silicon junction optimized for fast transient response (<1.0 ps rise time from 0 V to VBR) and low incremental surge resistance, enabling precise voltage clamping during high-energy transients. Its unidirectional architecture provides asymmetric conduction-low forward voltage drop in normal operation and rapid avalanche breakdown during overvoltage events.
Designed for single-pulse surge suppression per JEDEC-standard 8.3 ms half-sine wave or 10/1000 μs waveform, the SA45A delivers 500 W peak pulse power with thermal derating above 75°C ambient and supports non-repetitive forward surge currents up to 70 A. It operates across -65°C to +175°C junction temperature range without parameter drift.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power (10/1000 μs) | 500 W - sustains one-time surge energy up to 500 W without failure |
| Reverse Stand-off Voltage (VRWM) | 45 V - maximum continuous DC or RMS voltage before clamping initiates |
| Breakdown Voltage (VBR) | 50.0–55.3 V @ 1.0 mA - guaranteed avalanche onset range for reliable triggering |
| Clamping Voltage (VC) | 72.7 V @ 6.9 A - maximum voltage seen by protected circuit during rated surge |
| Reverse Leakage (IR) | <1.0 μA @ VRWM - negligible standby power loss and minimal loading on source |
| Junction Temperature (TJ) | +175°C - enables operation in high-ambient environments like motor control enclosures |
| Package | DO-15 - industry-standard axial leaded package with cathode band marking |
Pinout & Package
DO-15 package: axial-leaded, epoxy-molded, glass-passivated junction. Cathode indicated by color band on unidirectional devices. Leads are tinned copper, suitable for wave or hand soldering.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry point during forward conduction | Connected to ground or lower-potential rail in unidirectional clamp configuration |
| Cathode | Current exit point during forward conduction; avalanche terminal during reverse surge | Connected to protected line; clamps voltage to VC when transient exceeds VRWM |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Enhances long-term reliability and moisture resistance vs. epoxy-only passivation |
| Fast response time | <1.0 ps from 0 V to VBR - limits voltage overshoot before clamping engages |
| Low incremental surge resistance | Enables tighter clamping (VC − VBR = 22.7 V) versus competing TVS diodes |
| High junction temperature rating | +175°C operation - eliminates derating concerns in sealed industrial enclosures |
| JEDEC-compliant surge rating | 70 A non-repetitive IFSM - withstands motor-start inrush and transformer flyback spikes |
Applications
| Industrial Motor Drives | DC Power Supply Inputs |
|---|---|
Use Scenario: Protection of gate drivers and feedback sensors in variable-frequency drives exposed to IGBT switching noise and load dump transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed between DC bus and ground to clamp positive-going surges on isolated control rails. Use Value: Limits transient voltage to ≤72.7 V, preventing latch-up or permanent damage to 3.3 V/5 V logic interfaces downstream. |
Use Scenario: Input-stage surge suppression on 48 V telecom rectifier modules subjected to lightning-induced common-mode surges. IC Role / Device Role / Timing Role: Primary clamping device on DC input before bulk capacitor and upstream of DC-DC converters. Use Value: Absorbs 500 W peak energy without degradation, maintaining system uptime during Category III surge events per IEC 61000-4-5. |
| Automotive Body Control Modules | PLC Digital I/O Terminals |
Use Scenario: Protection of LIN bus transceivers and microcontroller GPIOs against battery disconnect transients and ISO 7637-2 pulse 1/2a. IC Role / Device Role / Timing Role: Unidirectional TVS connected anode-to-ground, cathode-to-LIN line to suppress negative transients only. Use Value: Reverse leakage <1.0 μA avoids signal distortion on low-current LIN bus; 45 V VRWM matches 12 V system nominal with margin. |
Use Scenario: Field-side protection on 24 V digital input cards receiving signals from proximity switches and limit sensors. IC Role / Device Role / Timing Role: Clamp diode installed between input terminal and internal optocoupler anode to shunt induced surges. Use Value: 72.7 V clamping ensures optocoupler LED remains within safe forward voltage range during 1 kV/μs transients. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ45A (ON Semiconductor) | Same VRWM (45 V), but SMB package (surface-mount); 600 W Pppm; slightly higher VC (73.5 V) | Requires PCB redesign for SMT placement; better suited for space-constrained designs | Select when board real estate is limited and reflow capability exists |
| P4KE45A (Littelfuse) | Same DO-15 package and VRWM; 400 W Pppm; higher VC (76.0 V); 1000 W peak for 1.0 ms | Limited to lower-energy transients; less effective clamping margin for 500 W threats | Acceptable for cost-sensitive, lower-risk applications where full 500 W rating is not required |
Compared with SMBJ45A and P4KE45A, the SA45A offers optimal balance of through-hole manufacturability, 500 W surge capacity, and tight 72.7 V clamping-making it preferred for industrial power supplies and motor controllers where legacy DO-15 footprint and robust single-pulse handling are critical.
Availability
SA45A is available at Aetrix Electronics and suitable for industrial motor drives, DC power supply inputs, and PLC digital I/O terminals requiring stable component supply and long-lifecycle support.
Supply support for SA45A 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 in industrial systems.
The SAxxA series was designed specifically for high-reliability, high-energy transient suppression in harsh environments-targeting applications where surge immunity, thermal stability, and long-term parametric consistency are mandatory.
FAQ
What is the clamping voltage of the SA45A under rated surge conditions?
The SA45A exhibits a maximum clamping voltage (VC) of 72.7 V when subjected to its rated peak pulse current of 6.9 A on a 10/1000 μs waveform. This value is measured per standard test conditions (TA = 25°C, IT = 1.0 mA) and defines the upper voltage limit imposed on protected circuits during transient events. The SA45A maintains this clamping performance consistently across its operating temperature range.
Is the SA45A suitable for bidirectional surge protection?
No, the SA45A is a unidirectional TVS diode, intended only for DC-biased or polarity-defined surge protection. Bidirectional variants in the same family carry the "C" suffix (e.g., SA45CA). Using SA45A in AC or bipolar signal paths risks failure during reverse-polarity transients, as it lacks symmetrical clamping capability. Always verify polarity alignment before deploying SA45A.
What is the maximum junction temperature rating for the SA45A?
The SA45A has a maximum operating junction temperature (TJ) of +175°C, allowing reliable operation in high-ambient environments such as enclosed motor drive cabinets or under-hood automotive modules. This rating is validated per absolute maximum specifications and supports uninterrupted function even when ambient temperatures approach 125°C with appropriate PCB copper pour and airflow.
Does the SA45A meet any international surge immunity standards?
The SA45A's 500 W peak pulse power rating on the 10/1000 μs waveform aligns with test levels defined in IEC 61000-4-5 for surge immunity (e.g., 2 kV line-to-earth, 1 kV line-to-line in Level 3). While the device itself is not certified to a standard, its electrical characteristics enable compliant system-level design when properly applied in conjunction with impedance-matching layout practices and coordinated protection staging.
How does the SA45A compare to the P4KE45A in terms of surge handling capability?
The SA45A delivers 500 W peak pulse power on the 10/1000 μs waveform, whereas the P4KE45A is rated for 400 W under identical conditions. Additionally, SA45A achieves lower clamping voltage (72.7 V vs. 76.0 V) at its respective IPPM, offering superior voltage limiting. Both use DO-15 packaging, but SA45A's higher energy absorption and tighter clamping make it preferable for demanding industrial surge environments.
SA45A 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:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 45V
- Voltage - Breakdown (Min):
- 50V
- Voltage - Clamping (Max) @ Ipp:
- 72.7V
- Current - Peak Pulse (10/1000µs):
- 6.9A
- 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
SA45A FAQ
1.How can I place an order for SA45A through Aetrix?
Please submit a Request for Quotation (RFQ) for SA45A 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 SA45A reliable?
The price and inventory of SA45A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SA45A is usually 5 days.
3.What payment methods are accepted for SA45A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SA45A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SA45A?
SA45A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SA45A 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 SA45A?
For technical support, including SA45A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SA45A requirements.
6.How does Aetrix verify that SA45A is sourced from the original manufacturer or authorized distributors?
All SA45A 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 SA45A meets industry standards.
7.What is the process for return or replacement of SA45A?
All SA45A units undergo pre-shipment inspection (PSI). If there is an issue with SA45A, 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 SA45A part is unused and in its original packaging.
Return procedure for SA45A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SA45A 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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Diodes Incorporated
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D5V0P1B2LP-7B
Diodes Incorporated
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DESD5V0U1BA-7
Diodes Incorporated
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ESD5Z5.0T1G
onsemi
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DESD5V0U1BB-7
Diodes Incorporated
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D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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