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STMicroelectronics SMA6T33AY
- Part No.:
- SMA6T33AY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMA6T33AY.pdf
- Description:
- TVS DIODE 28.2VWM 59VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:4,989
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Product details
Overview
SMA6T33AY from STMicroelectronics is a unidirectional 600 W automotive-grade transient voltage suppression (TVS) diode in SMA package, designed to clamp ISO 7637-2 pulses (Pulse 1: −150 V; Pulse 2a: +112 V; Pulse 3a: −220 V; Pulse 3b: +150 V) and suppress ESD per ISO 10605 (±30 kV air/contact). It features 33 V breakdown voltage (VBR = 31.4–34.7 V), 45.7 V clamping voltage (VCL) at 13.1 A (10/1000 µs), and 0.2 µA leakage at 25 °C - enabling robust protection for 12 V/24 V automotive power rails.
For engineers reviewing the SMA6T33AY datasheet, SMA6T33AY pinout, SMA6T33AY application, or SMA6T33AY equivalent, key selection criteria include its AEC-Q101 qualification, 150 °C max junction temperature, JEDEC DO-214AC (SMA) package compatibility, low dynamic resistance (0.84 Ω), and compliance with IEC 61000-4-4 Level 4 (4 kV) and ISO 7637-2 pulse immunity requirements.
Technical Context
This unidirectional TVS diode operates as a voltage-clamping surge protector in parallel with sensitive automotive electronics. Its planar silicon junction delivers low leakage (≤1 µA at 85 °C), high thermal stability (Tj up to 150 °C), and fast response to transients defined in ISO 7637-2 and ISO 10605.
The device uses a single PN junction structure optimized for high peak pulse power (600 W @ 10/1000 µs; 4 kW @ 8/20 µs) and low clamping ratio (VCL/VBR ≈ 1.46 at 25 °C). Its dynamic resistance of 0.84 Ω ensures minimal voltage overshoot during high-current surges, critical for protecting CAN, LIN, and sensor interface circuits.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min/typ/max) | 31.4 V / 33.0 V / 34.7 V - precise breakdown threshold ensures reliable triggering before downstream IC damage |
| VCL @ 13.1 A (10/1000 µs) | 45.7 V - clamps surge energy within safe margin for 36 V-rated components |
| IPP (10/1000 µs) | 13.1 A - supports full ISO 7637-2 Pulse 1 (−150 V) suppression on 12 V systems |
| RD (dynamic resistance) | 0.84 Ω - limits voltage rise under surge current, reducing stress on protected circuitry |
| IR @ VRM (25 °C) | 0.2 µA - ultra-low leakage preserves battery life in always-on automotive modules |
| Tj max | +150 °C - enables placement near hot engine-control units without derating |
| AEC-Q101 qualified | Yes - validated for automotive under-hood and powertrain applications per stress test standard |
Pinout & Package
Package: SMA (JEDEC DO-214AC), surface-mount, matte tin-plated leads, IPC7531-compliant footprint. Dimensions: D = 2.25–2.90 mm, E = 4.80–5.35 mm, E1 = 3.95–4.60 mm, L = 0.75–1.50 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked band) | Surge return path | Connected to ground or low-impedance reference; conducts during positive transients on anode side |
| Anode | Protected line input | Connected to power rail (e.g., battery feed); absorbs reverse-polarity surges when cathode is grounded |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive use including temperature cycling, humidity bias, and mechanical shock tests |
| ISO 7637-2 Pulse 1 immunity | Clamps −150 V transients on 12 V systems without failure or parameter shift |
| ESD robustness (ISO 10605) | Withstands ±30 kV contact/air discharge without degradation or leakage increase |
| Low Tj-dependent VBR drift | Temperature coefficient αT = 9.8 × 10−4/°C - stable clamping across −40 to +150 °C |
| JEDEC DO-214AC outline | Ensures drop-in compatibility with standard SMA footprints and automated assembly processes |
Applications
| Engine Control Unit (ECU) Power Input | Body Control Module (BCM) Battery Line |
|---|---|
Use Scenario: Protecting microcontroller power supply against load dump and alternator ripple in gasoline/diesel ECUs. IC Role / Device Role / Timing Role: Unidirectional shunt clamping device placed between battery rail and local DC/DC input. Use Value: Limits transient overvoltage to ≤45.7 V during ISO 7637-2 Pulse 1 (−150 V), preventing brownout or latch-up of 3.3 V/5 V regulators. |
Use Scenario: Safeguarding BCM power inputs exposed to jump-start surges and relay switching noise. IC Role / Device Role / Timing Role: Primary surge suppressor on 12 V main input, upstream of fuse and pre-regulator. Use Value: Absorbs 600 W peak power (10/1000 µs) without thermal runaway, maintaining <0.2 µA leakage at ambient temperatures up to 85 °C. |
| Automotive Camera Power Supply | Infotainment System USB Port Protection |
Use Scenario: Securing 12 V input to rear-view or ADAS cameras mounted near engine bay. IC Role / Device Role / Timing Role: First-line TVS on camera module's main power entry, before DC/DC conversion. Use Value: Survives repeated ISO 7637-2 Pulse 3a (−220 V) events while retaining VBR stability and low capacitance (<100 pF @ 0 V). |
Use Scenario: Protecting USB VBUS line in head unit against ESD and hot-plug transients. IC Role / Device Role / Timing Role: Low-leakage unidirectional TVS placed between USB connector and power switch. Use Value: Clamps ±30 kV ESD strikes (IEC 61000-4-2) within nanoseconds while adding <0.5 pF parasitic capacitance - preserving signal integrity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMA6T33A | Same electrical specs but non-AEC-Q101 qualified; no automotive reliability testing | Not suitable for production automotive ECUs or safety-critical modules | Select only for cost-sensitive industrial or consumer prototypes where AEC-Q101 is not mandated |
| SMBT33A | Higher VCL (48.4 V @ 12.2 A), lower PPP (400 W), SMB package (DO-214AA) | Larger footprint; insufficient for ISO 7637-2 Pulse 1 on 12 V systems | Acceptable only for lower-energy surges (e.g., IEC 61000-4-4 Level 3) in non-automotive 24 V applications |
Compared with SMA6T33A and SMBT33A, SMA6T33AY provides verified AEC-Q101 reliability, tighter VBR tolerance (±5%), and higher surge capability - making it the only choice for production automotive power rail protection requiring ISO 7637-2 compliance and long-term under-hood operation.
Availability
SMA6T33AY is available at Aetrix Electronics and suitable for automotive engine control units, body control modules, ADAS camera power supplies, and infotainment system USB protection requiring stable component supply across extended temperature ranges and high-reliability surge immunity.
Supply support for SMA6T33AY 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, MCU, power, and automotive ICs for industrial, automotive, and consumer markets.
SMA6T33AY belongs to the SMA6TY Transil series - engineered specifically for automotive-grade transient suppression in harsh environments, with emphasis on ISO 7637-2 pulse handling, AEC-Q101 compliance, and high-temperature reliability.
FAQ
What is the maximum clamping voltage of SMA6T33AY under ISO 7637-2 Pulse 1 conditions?
The SMA6T33AY clamps to 45.7 V at 13.1 A (10/1000 µs waveform), which corresponds directly to the −150 V ISO 7637-2 Pulse 1 test condition on a 12 V system. This value is measured at Tj = 25 °C and remains ≤47.2 V at Tj = 125 °C using the specified temperature coefficient (αT = 9.8 × 10−4/°C).
Can SMA6T33AY be used in bidirectional configurations?
No - SMA6T33AY is unidirectional only, with cathode marked and anode tied to the protected line. For bidirectional protection, ST offers the pin-compatible SMA6T33CAY variant, which has symmetrical breakdown in both polarities and identical clamping performance in either direction.
How does the 0.84 Ω dynamic resistance affect system-level surge protection?
The 0.84 Ω dynamic resistance determines the voltage overshoot during surge current flow: ΔV = IPP × RD. At 13.1 A, this adds only ~11 V above VBR, keeping total clamped voltage at 45.7 V - well below the 50 V absolute maximum rating of most automotive 3.3 V/5 V regulators and ensuring safe operation without secondary overvoltage stress.
Is the SMA6T33AY compatible with lead-free reflow soldering profiles?
Yes - SMA6T33AY uses matte tin-plated leads and is rated for MSL level 1 per J-STD-020, supporting standard Pb-free reflow profiles with peak temperature up to 260 °C for 10 seconds. Its JEDEC DO-214AC (SMA) package is fully compatible with IPC-7531 land patterns and automated SMT assembly lines.
SMA6T33AY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AC, SMA
- Series:
- SMA6TY, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 28.2V
- Voltage - Breakdown (Min):
- 31.4V
- Voltage - Clamping (Max) @ Ipp:
- 59V
- Current - Peak Pulse (10/1000µs):
- 68A (8/20µs)
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMA6T33AY FAQ
1.How can I place an order for SMA6T33AY through Aetrix?
Please submit a Request for Quotation (RFQ) for SMA6T33AY 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 SMA6T33AY reliable?
The price and inventory of SMA6T33AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMA6T33AY is usually 5 days.
3.What payment methods are accepted for SMA6T33AY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMA6T33AY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMA6T33AY?
SMA6T33AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMA6T33AY 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 SMA6T33AY?
For technical support, including SMA6T33AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMA6T33AY requirements.
6.How does Aetrix verify that SMA6T33AY is sourced from the original manufacturer or authorized distributors?
All SMA6T33AY 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 SMA6T33AY meets industry standards.
7.What is the process for return or replacement of SMA6T33AY?
All SMA6T33AY units undergo pre-shipment inspection (PSI). If there is an issue with SMA6T33AY, 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 SMA6T33AY part is unused and in its original packaging.
Return procedure for SMA6T33AY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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