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Taiwan Semiconductor Corporation SMA4S40AH
- Part No.:
- SMA4S40AH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- SOD-128
- Datasheet:
-
SMA4S40AH.pdf
- Description:
- TVS DIODE 40VWM 64.9VC SOD128
- Quantity:
- Payment:
- Shipping:
Inventory:28,000
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Product details
Overview
SMA4S40AH from Taiwan Semiconductor is a unidirectional 400W transient voltage suppressor (TVS) diode in SOD-128 package, with 40 V working stand-off voltage (VWM), 44.7–49.4 V breakdown voltage (VBR), and 64.9 V clamping voltage (VC) at 6.2 A peak pulse current. It is AEC-Q101 qualified and used for overvoltage protection in automotive BLDC motor drives and battery management systems.
For engineers reviewing the SMA4S40AH datasheet, SMA4S40AH pinout, SMA4S40AH application, or SMA4S40AH equivalent, key selection criteria include unidirectional polarity, 175°C max junction temperature, J-STD-020 Level 1 moisture sensitivity, UL 94V-0 molding compound, and compatibility with 5 mm × 5 mm copper pad PCB layouts.
Technical Context
This TVS diode operates as a unidirectional avalanche clamp, triggered when reverse voltage exceeds its specified VBR range (44.7–49.4 V @ 1 mA). Its 64.9 V clamping voltage at 6.2 A (10/1000 µs waveform) limits transient energy to protected circuits while sustaining 400 W non-repetitive peak pulse power.
Thermal performance is defined by RθJL = 20 °C/W and RθJA = 62 °C/W on a 5 mm × 5 mm Cu pad board. The device features glass-passivated junction, matte tin-plated leads compliant with J-STD-002, and meets JESD 201 Class 2 whisker resistance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 40 V - Maximum continuous reverse operating voltage before clamping begins |
| VBR min/max | 44.7 V / 49.4 V @ 1 mA - Confirmed breakdown threshold range under standard test conditions |
| VC @ IPPM | 64.9 V @ 6.2 A - Clamped voltage during 10/1000 µs surge, defining worst-case stress on downstream ICs |
| PPPM | 400 W - Peak pulse power handling capability per single transient event |
| TJ max | +175 °C - Maximum junction temperature enabling operation in under-hood automotive environments |
| Package | SOD-128 - Surface-mount outline with cathode band marking and 0.028 g mass |
| Mechanical Polarity | Uni-directional - Requires correct orientation in circuit; anode/cathode must match schematic layout |
Pinout & Package
Package: SOD-128 - molded surface-mount case with cathode band marking, 5 mm × 5 mm copper pad thermal interface, and matte tin-plated leads solderable per J-STD-002.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential side (e.g., ground or return path) in unidirectional TVS configuration |
| Cathode | Reverse-biased clamping terminal | Connected to protected line (e.g., 40 V rail); conducts avalanche current during overvoltage events |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive-grade reliability including temperature cycling, humidity bias, and mechanical shock testing |
| Glass-passivated junction | Enhances long-term stability and leakage control under high-humidity or high-temperature operating conditions |
| VBR tempco | 0.095 %/°C - Predictable voltage drift across -55°C to +175°C junction range |
| Moisture sensitivity level | Level 1 per J-STD-020 - No dry-pack or bake requirement prior to reflow assembly |
| UL 94V-0 molding compound | Self-extinguishing polymer housing suitable for safety-critical automotive and industrial enclosures |
Applications
| Automotive BLDC Motor Drive | Battery Management System (BMS) |
|---|---|
Use Scenario: Protection of gate drivers and MCU I/O against inductive kickback from 48 V BLDC motor phase switching. IC Role / Device Role / Timing Role: Unidirectional TVS placed between phase node and ground to clamp voltage spikes up to 64.9 V. Use Value: Prevents latch-up or permanent damage to 5 V or 3.3 V logic interfaces exposed to >100 V transients. | Use Scenario: Overvoltage suppression on cell monitor IC supply lines in 12–48 V lithium-ion battery packs. IC Role / Device Role / Timing Role: Standoff-rated clamp on analog front-end inputs and communication buses (e.g., SMBus, CAN PHY rails). Use Value: Maintains signal integrity during load dump or jump-start events without adding capacitance-induced timing skew. |
| LED Lighting Driver | Industrial SMPS Input Stage |
Use Scenario: Surge protection on constant-current LED driver outputs subjected to cable discharge events. IC Role / Device Role / Timing Role: Fast-response unidirectional clamp on output rail, rated for 40 V nominal bus voltage. Use Value: Enables compliance with IEC 61000-4-5 Level 3 (1 kV line-earth) without derating or parallel staging. | Use Scenario: Input-side transient suppression in 36–60 V industrial switch-mode power supplies. IC Role / Device Role / Timing Role: Primary-line TVS on DC input bus upstream of PFC controller and main converter stage. Use Value: Absorbs 400 W surges with <1 ns response time, preserving upstream EMI filter integrity and reducing MOV count. |
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 40 V VWM, but 400 W rating at 10/1000 µs; VC = 64.5 V @ 6.2 A; SOD-123 package (smaller thermal mass) | Lower RθJA (75 °C/W vs. 62 °C/W) limits sustained surge duty cycle in high-ambient environments | Prefer SMA4S40AH where PCB copper area is constrained but thermal margin is critical |
| SMCJ40A | Same 40 V VWM, 1500 W rating; VC = 64.3 V @ 23.3 A; larger SMC (DO-214AB) package | Higher peak power capacity suits infrequent high-energy transients, but requires more board space | Choose SMA4S40AH when footprint and weight are prioritized over extreme single-event energy absorption |
Compared with SMAJ40A and SMCJ40A, the SMA4S40AH delivers optimal balance of compact SOD-128 footprint, AEC-Q101 qualification, and verified 62 °C/W thermal resistance-making it preferred for space-constrained automotive modules requiring repeatable surge endurance.
Availability
SMA4S40AH is available at Aetrix Electronics and suitable for automotive BLDC motor drives, battery management systems, and industrial SMPS designs requiring stable component supply with full traceability and lifecycle support.
Supply support for SMA4S40AH 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, serving automotive, industrial, and consumer markets since 1979.
The SMA4SxxAH series is part of TSC's AEC-Q101-qualified TVS portfolio, engineered specifically for robust transient immunity in automotive powertrain and body electronics where reliability under thermal and mechanical stress is mandatory.
FAQ
What is the maximum clamping voltage of the SMA4S40AH under standard test conditions?
The SMA4S40AH has a maximum clamping voltage (VC) of 64.9 V when subjected to a 10/1000 µs waveform peak pulse current of 6.2 A. This value is measured at TA = 25°C and defines the upper voltage limit imposed on protected circuitry during transient events. The SMA4S40AH maintains this clamping performance across its full operating junction temperature range (-55°C to +175°C), with minimal derating required below 100°C ambient.
Is the SMA4S40AH suitable for automotive applications?
Yes, the SMA4S40AH is AEC-Q101 qualified and explicitly designed for automotive use. It meets stringent requirements for temperature cycling, mechanical shock, and humidity bias testing. Its 175°C maximum junction temperature, glass-passivated junction, and UL 94V-0 molding compound make it appropriate for under-hood BLDC motor controllers and battery management systems. The SMA4S40AH is referenced in TSC's automotive-grade TVS documentation as a recommended solution for 40 V system protection.
What is the polarity configuration of the SMA4S40AH?
The SMA4S40AH is a unidirectional TVS diode, meaning it functions as a reverse-biased avalanche clamp with defined anode and cathode terminals. The cathode is marked by a band on the SOD-128 package body. In normal operation, it blocks up to 40 V in reverse bias and conducts only during overvoltage transients. Forward conduction (anode positive) is not intended for protection use and exhibits ~3.5 V forward voltage at 25 A per datasheet specification.
How does the thermal performance of the SMA4S40AH compare to similar SOD-128 TVS diodes?
The SMA4S40AH achieves RθJA = 62 °C/W and RθJL = 20 °C/W when mounted on a 5 mm × 5 mm copper pad PCB-performance validated per JEDEC standards. This is 8–12% lower than typical industry values for same-package TVS devices, due to optimized die attach and leadframe design. These thermal metrics directly enable higher sustained surge repetition rates in automotive modules where ambient temperatures exceed 105°C.
What packaging and moisture sensitivity level applies to the SMA4S40AH?
The SMA4S40AH is supplied in SOD-128 package on tape-and-reel (14,000 units per reel) and has a moisture sensitivity level (MSL) of Level 1 per J-STD-020. This means the device may be stored indefinitely at ≤30°C/60% RH and requires no baking or dry-pack handling prior to surface-mount reflow. The matte tin-plated leads comply with J-STD-002 for solderability, and the UL 94V-0 molding compound ensures flame resistance during assembly and field operation.
SMA4S40AH Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- SOD-128
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 40V
- Voltage - Breakdown (Min):
- 44.7V
- Voltage - Clamping (Max) @ Ipp:
- 64.9V
- Current - Peak Pulse (10/1000µs):
- 6.2A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-128
SMA4S40AH FAQ
1.How can I place an order for SMA4S40AH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMA4S40AH 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 SMA4S40AH reliable?
The price and inventory of SMA4S40AH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMA4S40AH is usually 5 days.
3.What payment methods are accepted for SMA4S40AH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMA4S40AH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMA4S40AH?
SMA4S40AH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMA4S40AH 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 SMA4S40AH?
For technical support, including SMA4S40AH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMA4S40AH requirements.
6.How does Aetrix verify that SMA4S40AH is sourced from the original manufacturer or authorized distributors?
All SMA4S40AH 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 SMA4S40AH meets industry standards.
7.What is the process for return or replacement of SMA4S40AH?
All SMA4S40AH units undergo pre-shipment inspection (PSI). If there is an issue with SMA4S40AH, 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 SMA4S40AH part is unused and in its original packaging.
Return procedure for SMA4S40AH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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