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Vishay General Semiconductor - Diodes Division SA33A/54
- Part No.:
- SA33A/54
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-204AC, DO-15, Axial
- Datasheet:
-
SA33A/54.pdf
- Description:
- TVS DIODE 33VWM 53.3VC DO204AC
- Quantity:
- Payment:
- Shipping:
Inventory:8,969
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Product details
Overview
SA33A/54 from Littelfuse is a unidirectional Transient Voltage Suppressor (TVS) diode in DO-204AC (Axial) package, designed for primary overvoltage protection of DC power rails and signal lines. It features 33 V stand-off voltage (VWM), 36.7–40.6 V breakdown voltage (VBR), 53.3 V clamping voltage (VC) at 9.4 A peak pulse current, and 500 W peak pulse power rating with 10/1000 µs waveform - used in industrial power supplies and automotive control modules.
For engineers reviewing the SA33A/54 datasheet, SA33A/54 pinout, SA33A/54 application, or SA33A/54 equivalent, key selection criteria include its unidirectional polarity, 1.0 µA max reverse leakage at 33 V, -55°C to +175°C operating junction temperature, fast <1.0 ns response time, and compatibility with high-temperature soldering (265°C/10 s).
Technical Context
The SA33A/54 employs a glass-passivated silicon junction optimized for low incremental surge resistance and excellent clamping linearity under transient stress. Its unidirectional architecture provides asymmetric conduction: low forward voltage (≤3.5 V at 35 A) during surge conduction and high reverse blocking up to 33 V under normal operation.
It complies with ANSI/IEEE C62.35 for transient suppression and is rated for non-repetitive 10/1000 µs surges at 0.01% duty cycle. Thermal derating follows JEDEC standard mounting on 40 × 40 mm copper pad, with steady-state power dissipation of 3.0 W at TL = 75°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VWM) | 33.0 V - maximum continuous reverse working voltage before clamping initiates |
| Breakdown Voltage (VBR) | 36.7–40.6 V at 1.0 mA test current - defines precise clamping onset threshold |
| Clamping Voltage (VC) | 53.3 V at 9.4 A peak pulse - limits transient voltage seen by protected ICs |
| Peak Pulse Power (PPPM) | 500 W (10/1000 µs waveform) - sustains high-energy transients without failure |
| Reverse Leakage (ID) | ≤1.0 µA at 33 V - ensures minimal standby power loss and signal integrity |
| Response Time | <1.0 ns - enables protection of fast-edge digital interfaces and microcontrollers |
| Operating Temperature | -55°C to +175°C - supports under-hood automotive and industrial ambient conditions |
Pinout & Package
DO-204AC (Axial) molded plastic package with solder-plated axial leads; cathode indicated by color band; polarity-critical for unidirectional operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (non-banded end) | Reference/return node | Connected to system ground or low-side return path; carries full surge current during clamping |
| Cathode (banded end) | Protected line input | Connected to line being protected (e.g., 24 V rail); blocks 33 V DC but conducts above ~37 V |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable VBR tolerance and long-term reliability under thermal cycling |
| UL 94V-0 flammability rating | Meets safety standards for enclosed industrial and transportation equipment housings |
| High-temp soldering guarantee | Withstands 265°C for 10 s at 9.5 mm lead length - compatible with standard wave-solder processes |
| Low incremental surge resistance | Minimizes VC overshoot during fast-rising transients (e.g., ISO 7637-2 pulses) |
| 500 W surge capability | Handles IEC 61000-4-5 Level 4 (4 kV/2 Ω) surges without degradation when properly mounted |
Applications
| Industrial PLC I/O Protection | Automotive Body Control Module (BCM) |
|---|---|
Use Scenario: 24 V DC input channels in programmable logic controllers exposed to inductive kickback and ESD events. IC Role / Device Role / Timing Role: Primary shunt protector placed between field input and interface IC (e.g., optocoupler or level translator). Use Value: Clamps transients to ≤53.3 V, preventing damage to 3.3 V/5 V logic inputs downstream while maintaining 33 V nominal operation. |
Use Scenario: LIN bus or sensor supply lines in BCMs subjected to load dump and jump-start surges. IC Role / Device Role / Timing Role: Unidirectional TVS on 12 V/24 V subsystem rails upstream of LDOs and CAN/LIN transceivers. Use Value: Responds in <1 ns to suppress >100 V spikes, preserving signal integrity and enabling compliance with ISO 16750-2. |
| DC Power Supply Input Stage | Motor Drive Gate Driver Protection |
Use Scenario: Front-end protection of switched-mode power supplies in factory automation equipment. IC Role / Device Role / Timing Role: First-line defense against AC line transients coupled into DC bus via rectifier stage. Use Value: Absorbs 500 W surges without thermal runaway, reducing need for secondary crowbar circuits or larger bulk capacitors. |
Use Scenario: Protection of high-side/low-side gate driver ICs in BLDC motor inverters. IC Role / Device Role / Timing Role: Clamp induced voltage spikes on gate drive traces caused by parasitic inductance during switching. Use Value: Limits gate-source voltage excursion to safe levels (<60 V), preventing unintended MOSFET turn-on or oxide damage. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ33A | DO-214AA (SMB) surface-mount package; same VWM/VC, but lower IPPM (62.7 A vs. 9.4 A) and higher PPPM (600 W) | Requires PCB rework for SMT layout; better suited for space-constrained consumer boards than axial-reliant industrial assemblies | Select SMBJ33A only if board real estate is constrained and automated assembly is preferred. |
| P6KE33A | DO-15 package; identical VWM and VC, but lower PPPM (600 W) and higher VF (3.5 V), with 1000 W peak rating (10/1000 µs) | Same axial form factor but larger body; slightly higher thermal resistance limits sustained surge repetition | Choose P6KE33A where legacy DO-15 footprint compatibility is required and higher single-pulse energy margin is needed. |
Compared with SMBJ33A and P6KE33A, the SA33A/54 offers optimal balance of axial-mount robustness, low-profile mechanical integration, and verified 500 W surge handling in harsh environments - making it preferred for field-serviceable industrial hardware and high-vibration automotive harnesses.
Availability
SA33A/54 is available at Aetrix Electronics and suitable for industrial PLCs, automotive body control modules, and DC power supply input stages requiring stable component supply, long-lifecycle support, and traceable sourcing.
Supply support for SA33A/54 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
Littelfuse is a global leader in circuit protection, specializing in fuses, TVS diodes, and surge suppression solutions for industrial, automotive, and consumer markets.
The SAxxA series is part of Littelfuse's TransZorb™ TVS family, engineered specifically for cost-effective, high-reliability transient suppression in DC power and signal lines where axial mounting and high surge endurance are critical.
FAQ
What is the polarity configuration of SA33A/54?
The SA33A/54 is a unidirectional TVS diode: the banded end is the cathode and must be connected to the line being protected (e.g., +24 V rail), while the non-banded anode connects to ground or return. This configuration blocks 33 V DC in reverse bias and clamps positive transients above ~37 V. Polarity reversal will cause permanent failure under normal operating voltage.
Does SA33A/54 meet automotive qualification standards?
The SA33A/54 is not AEC-Q200 qualified, but its -55°C to +175°C operating junction temperature range, 265°C soldering tolerance, and compliance with ANSI/IEEE C62.35 make it widely deployed in non-safety-critical automotive applications such as body control modules and infotainment power rails. For ASIL-B/C systems, AEC-Q200-qualified alternatives like SMAJ33A should be evaluated.
How does SA33A/54 compare to bidirectional variants like SA33CA?
The SA33A/54 is unidirectional and protects against positive-going transients only, whereas SA33CA provides symmetrical clamping for AC or floating lines. SA33A/54 has lower capacitance and faster response (<1.0 ns vs. 5.0 ns), making it preferable for DC rails with defined polarity. SA33CA would be inappropriate for 24 V DC systems due to unnecessary reverse conduction path.
What is the maximum allowable surge repetition rate for SA33A/54?
The SA33A/54 is rated for non-repetitive 10/1000 µs surges at 0.01% duty cycle per datasheet Note 1. In practice, this allows ≤1 surge per 100 seconds at full 500 W. For repetitive threats (e.g., motor commutation noise), thermal derating per Figure 2 must be applied - at 75°C ambient, peak pulse power drops to ~300 W, limiting usable repetition to ~1 pulse per 3 minutes under worst-case conditions.
Can SA33A/54 be used in parallel for higher surge current handling?
No - SA33A/54 devices should not be paralleled without external balancing resistors. Minor VBR tolerances (36.7–40.6 V) cause current sharing imbalance, leading to thermal runaway in one device. For >9.4 A peak pulse current, select a higher-rated part (e.g., SA43A/54) or use a multi-stage protection scheme with upstream current-limiting impedance.
SA33A/54 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-204AC, DO-15, Axial
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 33V
- Voltage - Breakdown (Min):
- 36.7V
- Voltage - Clamping (Max) @ Ipp:
- 53.3V
- Current - Peak Pulse (10/1000µs):
- 9.4A
- 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)
SA33A/54 FAQ
1.How can I place an order for SA33A/54 through Aetrix?
Please submit a Request for Quotation (RFQ) for SA33A/54 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 SA33A/54 reliable?
The price and inventory of SA33A/54 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SA33A/54 is usually 5 days.
3.What payment methods are accepted for SA33A/54?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SA33A/54 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SA33A/54?
SA33A/54 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SA33A/54 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 SA33A/54?
For technical support, including SA33A/54 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SA33A/54 requirements.
6.How does Aetrix verify that SA33A/54 is sourced from the original manufacturer or authorized distributors?
All SA33A/54 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 SA33A/54 meets industry standards.
7.What is the process for return or replacement of SA33A/54?
All SA33A/54 units undergo pre-shipment inspection (PSI). If there is an issue with SA33A/54, 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 SA33A/54 part is unused and in its original packaging.
Return procedure for SA33A/54:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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