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Taiwan Semiconductor Corporation SA40A
- Part No.:
- SA40A
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-204AC, DO-15, Axial
- Datasheet:
-
SA40A.pdf
- Description:
- TVS DIODE 40VWM 64.5VC DO204AC
- Quantity:
- Payment:
- Shipping:
Inventory:9,366
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Product details
Overview
SA40A from Taiwan Semiconductor is a unidirectional 40V working stand-off transient voltage suppressor (TVS) diode in DO-204AC (DO-15) package, rated for 500W peak pulse power at 10/1000μs, with 44.4–49.1V breakdown voltage, 64.5V clamping voltage at 8.1A, and <1μA reverse leakage above 10V - deployed for ESD and surge protection in automotive lighting control modules.
For engineers reviewing the SA40A datasheet, SA40A pinout, SA40A application, or SA40A equivalent, key selection criteria include its AEC-Q101 qualification status, unidirectional polarity marking, 175°C junction temperature rating, and compatibility with J-STD-002 solderable tin-plated leads in high-reliability industrial and automotive PCB layouts.
Technical Context
The SA40A operates as a silicon avalanche diode optimized for fast clamping of transient overvoltages. Its breakdown occurs at 44.4–49.1V under 1mA test current, with clamping voltage limited to 64.5V at 8.1A peak pulse current - ensuring protected circuits remain below safe voltage thresholds during 10/1000μs surges.
It exhibits low dynamic impedance and sub-nanosecond response (<1.0ps from 0V to VBR), enabling effective suppression of ESD events per IEC 61000-4-2 and electrical fast transients per IEC 61000-4-4. Thermal derating follows Fig.2, maintaining 500W capability only at TA ≤ 25°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 40 V - Maximum continuous reverse operating voltage before significant leakage begins; defines circuit's maximum normal-state bus voltage. |
| VBR @ IT=1mA | 44.4–49.1 V - Breakdown onset range; ensures reliable triggering above system nominal voltage with margin against tolerance drift. |
| VC @ IPPM=8.1A | 64.5 V - Clamped voltage during 500W surge; determines maximum stress imposed on downstream ICs during transient events. |
| PPK | 500 W - Peak pulse power handling at 10/1000μs waveform; validates robustness against ISO 7637-2 Pulse 1/2a/3a and IEC 61000-4-5 surges. |
| IR @ VWM | <1 μA - Reverse leakage at 40V; minimizes standby power loss and avoids false triggering in high-impedance sensing nodes. |
| TJMAX | 175 °C - Maximum junction temperature; supports operation in under-hood automotive environments and thermally constrained enclosures. |
Pinout & Package
Package: DO-204AC (DO-15), axial leaded, epoxy-molded case with cathode band marking for unidirectional polarity. Meets UL 94V-0 flammability and JESD201 Class 2 whisker resistance requirements.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to ground or low-voltage return path; forms clamping loop with cathode during transient conduction. |
| Cathode | High-side surge input terminal | Connected to protected line (e.g., 12V rail); conducts avalanche current to anode when VAK exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing - suitable for front-end power rails in ADAS and body control modules. |
| Clamping voltage ≤64.5V at 8.1A | Ensures protected microcontrollers and CAN transceivers remain within absolute maximum ratings during 500W transients. |
| Response time <1.0ps | Enables suppression of nanosecond-scale ESD events before sensitive gate oxides experience damage. |
| RoHS & halogen-free | Complies with IEC 61249-2-21 and EU RoHS Directive 2011/65/EU - required for global automotive OEM supply chains. |
Applications
| Automotive Lighting Control | Industrial PLC Input Protection |
|---|---|
Use Scenario: Protecting LED driver ICs and MOSFET gate drivers in headlamp control units subjected to load dump and ISO 7637-2 Pulse 2a. IC Role / Device Role / Timing Role: Unidirectional TVS placed between 12V supply rail and ground, clamping transients before they reach power management ICs. Use Value: Limits voltage excursion to ≤64.5V during 500W surges, preventing latch-up or permanent damage to 40V-rated buck controllers. | Use Scenario: Safeguarding 24V digital input channels on programmable logic controllers exposed to inductive kickback from solenoid valves. IC Role / Device Role / Timing Role: Standoff protector on field-side input traces, absorbing energy from 10/1000μs transients induced by relay switching. Use Value: Maintains signal integrity by holding input voltage below 64.5V while delivering 8.1A peak surge current without degradation. |
| USB-C Power Delivery Interface | Smart Building Sensor Node |
Use Scenario: Secondary-level surge protection on 20V PP (power path) lines in USB-C PD sink adapters compliant with IEC 61000-4-5 Level 3. IC Role / Device Role / Timing Role: Fast-clamping device parallel to DC-DC converter input, triggered only during overvoltage events exceeding 40V. Use Value: Provides 500W transient immunity without affecting steady-state efficiency due to <1μA leakage at 40V. | Use Scenario: ESD hardening of RS-485 transceiver power pins in battery-powered environmental sensors deployed in HVAC ducts. IC Role / Device Role / Timing Role: Low-leakage standoff protector on VCC rail, activated only during human-body-model (HBM) ESD strikes. Use Value: Survives >15kV contact discharge per IEC 61000-4-2 while adding negligible quiescent current to 10-year battery life designs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ40A | Same DO-214AC package; 44.4–49.1V VBR, 64.4V VC @ 8.1A, but rated for 400W PPK (vs. SA40A's 500W). | Lower peak power rating limits suitability for ISO 7637-2 Pulse 1 (inductive load dump) in 12V systems. | Select SMAJ40A only if board space requires SMD mounting and 400W suffices; SA40A preferred for through-hole robustness and higher surge margin. |
| 1.5KE40A | DO-201AD package; identical 40V VWM, 44.4–49.1V VBR, but 64.5V VC @ 7.8A and 500W rating - slightly lower IPPM. | Larger footprint and higher thermal mass; less suitable for compact automotive modules where DO-15 lead spacing is optimized. | Choose 1.5KE40A when legacy board designs require DO-201AD mechanical fit; SA40A offers tighter lead pitch and AEC-Q101 qualification not guaranteed for 1.5KE series. |
Compared with SMAJ40A and 1.5KE40A, the SA40A delivers equal clamping performance with superior 500W surge capacity in a smaller DO-15 outline, AEC-Q101 validation for automotive use, and verified <1μA leakage - making it optimal for space-constrained, high-reliability 12V/24V rail protection.
Availability
SA40A is available at Aetrix Electronics and suitable for automotive lighting control, industrial PLC input protection, and USB-C power delivery interface designs requiring stable component supply, long-term lifecycle support, and AEC-Q101-compliant surge immunity.
Supply support for SA40A 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 semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in discrete power devices, TVS diodes, rectifiers, and thyristors since 1979.
The SA Series was developed specifically for automotive and industrial transient suppression, emphasizing AEC-Q101 compliance, tight VBR tolerances, and consistent clamping behavior across temperature - targeting 12V/24V/48V system front-end protection.
FAQ
What is the polarity configuration of the SA40A?
The SA40A is a unidirectional TVS diode with cathode band marking on the DO-204AC (DO-15) package. It conducts avalanche current only when the cathode is biased positive relative to the anode, making it suitable for DC rail protection where polarity is fixed - unlike bidirectional variants such as SA40CA.
Does the SA40A meet AEC-Q101 requirements?
Yes, the SA40A is explicitly qualified to AEC-Q101 standards as confirmed in the SA Series datasheet Version L2105. This includes stress testing for temperature cycling, high-temperature reverse bias (HTRB), and ESD - validating its suitability for automotive powertrain and body electronics applications.
What is the maximum clamping voltage of the SA40A during a 500W transient?
The SA40A clamps to a maximum of 64.5V at 8.1A peak pulse current (10/1000μs waveform), which corresponds precisely to its 500W peak pulse power rating. This value is measured and guaranteed per ANSI/IEEE C62.35 and appears in the "Maximum clamping voltage VC@IPPM" row of the SA40A parametric table.
Can the SA40A be used in bidirectional signal line protection?
No, the SA40A is unidirectional only and must not be used on AC or bidirectional data lines. For such applications, select the SA40CA variant - a bidirectional version with symmetrical breakdown in both directions and no polarity marking, as specified in the SA Series documentation.
What is the junction-to-ambient thermal resistance (RθJA) of the SA40A?
The SA40A datasheet does not specify RθJA directly; instead, thermal performance is defined via derating curves (Fig.2) and steady-state power dissipation (PD = 3W at TL = 75°C on 10×10 mm copper pads). Designers must apply these empirical curves rather than calculate using RθJA for layout-dependent thermal modeling.
SA40A 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):
- 40V
- Voltage - Breakdown (Min):
- 44.4V
- Voltage - Clamping (Max) @ Ipp:
- 64.5V
- Current - Peak Pulse (10/1000µs):
- 8.1A
- 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)
SA40A FAQ
1.How can I place an order for SA40A through Aetrix?
Please submit a Request for Quotation (RFQ) for SA40A 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 SA40A reliable?
The price and inventory of SA40A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SA40A is usually 5 days.
3.What payment methods are accepted for SA40A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SA40A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SA40A?
SA40A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SA40A 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 SA40A?
For technical support, including SA40A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SA40A requirements.
6.How does Aetrix verify that SA40A is sourced from the original manufacturer or authorized distributors?
All SA40A 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 SA40A meets industry standards.
7.What is the process for return or replacement of SA40A?
All SA40A units undergo pre-shipment inspection (PSI). If there is an issue with SA40A, 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 SA40A part is unused and in its original packaging.
Return procedure for SA40A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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