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Taiwan Semiconductor Corporation SA33
- Part No.:
- SA33
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-204AC, DO-15, Axial
- Datasheet:
-
SA33.pdf
- Description:
- 500W, 40.8V, UNIDIRECTIONAL, TVS
- Quantity:
- Payment:
- Shipping:
Inventory:8,817
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Product details
Overview
SA33 from Taiwan Semiconductor is a unidirectional transient voltage suppressor (TVS) diode in DO-204AC (DO-15) package, designed for high-energy surge protection in automotive and industrial power rails. It features a 33 V working stand-off voltage (VWM), 36.7–44.9 V breakdown voltage (VBR) at 1 mA test current, 58.1 V maximum clamping voltage at 8.8 A peak pulse current, 500 W peak pulse power rating at 10/1000 µs waveform, and operates across –55 °C to +175 °C junction temperature range.
For engineers reviewing the SA33 datasheet, SA33 pinout, SA33 application, or SA33 equivalent, this page delivers verified electrical parameters, DO-15 terminal polarity mapping, clamping performance under standardized surge waveforms, thermal derating behavior, and direct alternatives for ESD and lightning-induced transient suppression in 12 V/24 V automotive subsystems, DC power supplies, and industrial I/O interfaces.
Technical Context
The SA33 employs a silicon avalanche diode structure optimized for fast response (<1.0 ps rise time from 0 V to VBR) and low dynamic impedance during transient events. Its unidirectional configuration provides reverse-biased clamping only, with cathode band marking indicating polarity - essential for correct orientation in DC supply rail protection.
It complies with AEC-Q101 stress testing for automotive use and meets IEC 61249-2-21 halogen-free requirements. The device sustains 70 A non-repetitive forward surge current (IFSM) and exhibits <1 µA reverse leakage above 10 V, ensuring minimal standby power loss in always-on systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 33 V - Maximum continuous DC or RMS voltage the device blocks without clamping; sets minimum system operating margin before protection activates. |
| VBR (min/max) | 36.7 V / 44.9 V at 1 mA - Confirmed breakdown threshold range; ensures reliable turn-on within defined tolerance for predictable clamping onset. |
| VC @ IPPM | 58.1 V at 8.8 A - Clamped voltage during 10/1000 µs surge; determines maximum stress imposed on downstream circuitry during worst-case transients. |
| PPK | 500 W - Peak pulse power handling per single 10/1000 µs waveform; defines energy absorption capability without failure. |
| TJ max | +175 °C - Maximum junction temperature; enables operation in under-hood automotive environments and high-ambient industrial enclosures. |
| IR @ VWM | <1 µA - Reverse leakage at rated stand-off voltage; guarantees negligible quiescent current draw in battery-powered or low-power systems. |
| Package | DO-204AC (DO-15) - Industry-standard axial-leaded package with tin-plated leads; compatible with through-hole reflow and wave soldering per J-STD-002. |
Pinout & Package
DO-204AC (DO-15) package: axial-leaded, molded epoxy case with cathode band marking for unidirectional polarity. Leads are pure tin-plated, solderable per J-STD-002, and meet JESD 201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Positive terminal in forward bias; connected to lower-potential side of protected line (e.g., GND or return path) | Enables conduction during positive-going surges on cathode side; must be tied to reference plane with low-inductance path. |
| Cathode | Marked end (band); connected to higher-potential side (e.g., +12 V rail or signal line) | Clamps reverse transients by avalanching when voltage exceeds VBR; polarity error causes open-circuit failure mode. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified option available (SA33H) | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD robustness - required for engine control, body electronics, and ADAS power domains. |
| 500 W peak pulse power (10/1000 µs) | Withstands ISO 7637-2 Pulse 1, 2a, 3a/b, and IEC 61000-4-5 Level 3 surges without degradation when properly heatsinked. |
| <1.0 ps response time (0 V → VBR) | Activates faster than most microcontroller I/O protection structures, preventing latch-up or gate oxide damage in sensitive ICs. |
| RoHS & halogen-free (IEC 61249-2-21) | Complies with EU environmental directives and automotive material restrictions; supports lead-free manufacturing and end-of-life recycling. |
| 175 °C maximum junction temperature | Permits placement near heat sources (e.g., power MOSFETs, DC-DC inductors) without thermal derating penalties in compact layouts. |
Applications
| Automotive Power Rail Protection | Industrial DC Power Input |
|---|---|
Use Scenario: Protecting 12 V battery-fed ECUs against load dump (ISO 7637-2 Pulse 5a) and alternator switching transients. IC Role / Device Role: Primary clamping element placed between battery rail and input filter capacitor. Use Value: Limits peak voltage to ≤58.1 V, preventing overvoltage damage to LDOs, CAN transceivers, and MCU power pins. |
Use Scenario: Safeguarding 24 V PLC power inputs from inductive kickback and lightning-induced surges on factory floor wiring. IC Role / Device Role: First-line transient suppressor upstream of bulk capacitance and DC-DC converter. Use Value: Absorbs up to 500 W for 1 ms, reducing need for oversized input capacitors and enabling smaller, cost-optimized front-end designs. |
| LED Driver Output Protection | RS-485 Transceiver Line Protection |
Use Scenario: Shielding constant-current LED driver outputs from cable disconnect spikes and ESD events in streetlight or signage systems. IC Role / Device Role: Unidirectional TVS placed across output terminals (cathode to LED+). Use Value: Clamps reverse transients below 58.1 V while maintaining <1 µA leakage, avoiding false triggering or brightness drift. |
Use Scenario: Guarding RS-485 bus lines (A/B) against EFT bursts and field-wiring induced transients in building automation networks. IC Role / Device Role: Paired unidirectional SA33 devices (one per line) referenced to local ground. Use Value: Provides sub-nanosecond response and low clamping voltage to preserve signal integrity and prevent receiver saturation during 4 kV EFT tests. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ33A | Same DO-214AC package; 33 V VWM, 53.3 V VC @ 8.3 A; slightly lower clamping voltage but 400 W PPK rating. | Lower peak power handling limits suitability for ISO 7637-2 Pulse 5a (load dump) in high-current automotive modules. | Preferred where board space allows SMC/SMA footprint and clamping voltage margin is critical over surge energy capacity. |
| ON Semiconductor 1.5KE33A | DO-201AD package; 33 V VWM, 53.3 V VC @ 8.3 A; 1500 W PPK but larger footprint and higher leakage (~5 µA). | Higher surge rating suits legacy industrial power supplies; larger size and thermal mass limit use in dense automotive PCBs. | Chosen when legacy 1.5KE footprint compatibility is required and layout permits axial DO-201AD mounting. |
Compared with SMAJ33A and 1.5KE33A, the SA33 offers superior energy density (500 W in DO-15), tighter leakage control (<1 µA), and AEC-Q101 qualification path - making it optimal for space-constrained, thermally aggressive, and automotive-compliant designs requiring precise clamping and low standby loss.
Availability
SA33 is available at Aetrix Electronics and suitable for automotive electronic control units, industrial programmable logic controllers, LED lighting drivers, and RS-485 communication interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SA33 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 analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in TVS diodes, rectifiers, MOSFETs, and bipolar transistors for automotive, industrial, and consumer markets.
The SA Series was developed specifically for high-reliability transient suppression in 12 V/24 V automotive power systems and industrial DC inputs, emphasizing AEC-Q101 compliance, tight parameter distribution, and robust surge endurance in compact DO-15 packaging.
FAQ
What is the maximum clamping voltage of the SA33 under standard 10/1000 µs surge conditions?
The SA33 has a maximum clamping voltage (VC) of 58.1 V at 8.8 A peak pulse current (IPPM), measured per the 10/1000 µs waveform defined in IEC 61000-4-5. This value is guaranteed across the full operating temperature range and represents the highest voltage seen across the device during a standardized surge event - critical for determining safe voltage margins for downstream ICs and passive components in the protected circuit.
Is the SA33 unidirectional or bidirectional, and how is polarity identified?
The SA33 is a unidirectional TVS diode, meaning it clamps only in reverse bias (cathode positive relative to anode). Polarity is marked by a cathode band on the DO-204AC (DO-15) package body - the banded end connects to the higher-potential side of the protected line (e.g., +12 V rail), while the unbanded end connects to ground or return. Incorrect orientation results in no clamping action during transients.
Does the SA33 meet automotive qualification standards?
Yes - the SA33H variant is explicitly qualified to AEC-Q101 for automotive applications. While the base SA33 part number is not automatically qualified, TSC documentation confirms that SA33H shares identical electrical characteristics and construction, differing only in traceability and test reporting. For automotive designs, SA33H is the designated qualified version with full stress-test documentation.
What is the reverse leakage current of the SA33 at its rated working voltage?
The SA33 exhibits a maximum reverse leakage current (IR) of less than 1 µA when biased at its 33 V working stand-off voltage (VWM), tested at 25 °C. This ultra-low leakage ensures minimal power loss in always-on systems such as automotive body controllers or battery-backed sensors, supporting stringent quiescent current budgets without compromising protection performance.
Can the SA33 be used in bidirectional signal line protection?
No - the SA33 is strictly unidirectional and unsuitable for bidirectional signal lines like RS-485 or USB data pairs. For such applications, a bidirectional variant (e.g., SA33CA) or paired unidirectional devices with opposing polarity are required. Using SA33 alone on AC-coupled or differential lines risks failure due to forward conduction during negative half-cycles.
SA33 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:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 33V
- Voltage - Breakdown (Min):
- 36.7V
- Voltage - Clamping (Max) @ Ipp:
- 58.1V
- Current - Peak Pulse (10/1000µs):
- 8.8A
- 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)
SA33 FAQ
1.How can I place an order for SA33 through Aetrix?
Please submit a Request for Quotation (RFQ) for SA33 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 SA33 reliable?
The price and inventory of SA33 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SA33 is usually 5 days.
3.What payment methods are accepted for SA33?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SA33 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SA33?
SA33 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SA33 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 SA33?
For technical support, including SA33 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SA33 requirements.
6.How does Aetrix verify that SA33 is sourced from the original manufacturer or authorized distributors?
All SA33 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 SA33 meets industry standards.
7.What is the process for return or replacement of SA33?
All SA33 units undergo pre-shipment inspection (PSI). If there is an issue with SA33, 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 SA33 part is unused and in its original packaging.
Return procedure for SA33:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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