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STMicroelectronics SM15T24AY
- Part No.:
- SM15T24AY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM15T24AY.pdf
- Description:
- TVS DIODE 20.5VWM 42.8VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:2,500
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Product details
Overview
SM15T24AY from STMicroelectronics is a unidirectional automotive-grade transient voltage suppression (TVS) diode in SMC package, designed to protect 24 V automotive power nets against ISO 7637-2 pulses (Pulse 1: −150 V; Pulse 2a: +112 V; Pulse 3a: −220 V; Pulse 3b: +150 V) and ESD per ISO 10605 (±30 kV air/contact). It features 24 V nominal breakdown voltage (VBR = 20.5–25.2 V), 33.2 V clamping voltage (VCL) at 10/1000 µs, and 1500 W peak pulse power rating.
For engineers reviewing the SM15T24AY datasheet, SM15T24AY pinout, SM15T24AY application, or SM15T24AY equivalent, this device is selected for robust front-end protection in automotive body control modules, infotainment power supplies, and ADAS sensor interfaces where low leakage (0.2 µA @ 25 °C), high junction temperature operation (Tj max = 150 °C), and AEC-Q101 qualification are mandatory.
Technical Context
This TVS diode uses planar silicon technology to achieve stable VBR temperature coefficient (αT = 9.4 × 10−4/°C) and low dynamic resistance (RD = 0.178 Ω at 10/1000 µs). Its unidirectional configuration provides asymmetric clamping-low forward voltage drop (<2.5 V @ 100 A) during reverse surge events while blocking normal 24 V system voltage.
It meets IEC 61000-4-4 Level 4 (4 kV), exceeds ISO 10605 Level 4 (±30 kV), and supports full ISO 7637-2 compliance for 12 V/24 V battery systems. The SMC package enables high thermal dissipation with Rth(j-a) ≤ 120 °C/W on recommended 3.14 cm² copper area.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min/typ/max) | 20.5 / 22.8 / 24 V - Ensures reliable turn-on before 24 V rail overvoltage damages downstream MOSFETs or regulators |
| VCL @ 10/1000 µs | 33.2 V - Clamps transients to safe level for 3.3 V/5 V logic ICs powered from protected 24 V supply |
| IPP @ 10/1000 µs | 45 A - Supports surge current handling for ISO 7637-2 Pulse 3b (+150 V) on 24 V systems |
| RD | 0.178 Ω - Low dynamic resistance minimizes clamping voltage rise under high-current surges |
| IR @ VRM | 0.2 µA @ 25 °C - Ultra-low leakage preserves battery life in always-on automotive modules |
| Tj max | 150 °C - Enables operation in engine bay environments without derating below 1250 W peak power |
| AEC-Q101 | Qualified - Validated for automotive use including temperature cycling, HTRB, and ESD stress |
Pinout & Package
The SM15T24AY is housed in an SMC (DO-214AB) surface-mount package with two terminals: Cathode (marked side) and Anode. Matte tin-plated leads comply with J-STD-002 and MIL-STD-750 Method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked end) | Surge current sink | Connected to protected line (e.g., 24 V supply rail); conducts during negative transients and ESD events |
| Anode | Reference node | Connected to ground or low-impedance return path; defines clamping reference for unidirectional operation |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive underhood and cabin applications per stress test requirements (HTOL, TC, UHAST) |
| 1500 W peak pulse power (10/1000 µs) | Handles worst-case ISO 7637-2 Pulse 3a (−220 V) on 24 V systems without failure |
| Low leakage: 0.2 µA @ 25 °C | Minimizes standby current draw in always-on modules such as telematics and gateway ECUs |
| Clamping voltage ≤ 33.2 V @ 45 A | Protects downstream DC-DC converters and microcontrollers rated for ≤ 36 V absolute maximum |
| Planar silicon construction | Delivers stable VBR drift and low capacitance (<1000 pF @ 0 V) for high-speed signal integrity |
Applications
| Body Control Module (BCM) | Infotainment Power Supply |
|---|---|
Use Scenario: Protects 24 V input of BCM power management ICs against load dump and alternator ripple. IC Role / Device Role / Timing Role: Front-end transient suppressor placed directly at connector entry point before DC-DC converter. Use Value: Prevents latch-up or destruction of buck controller ICs during ISO 7637-2 Pulse 1 (−150 V) and Pulse 2a (+112 V). |
Use Scenario: Shields USB-C PD and display power rails in head unit from battery line transients. IC Role / Device Role / Timing Role: Unidirectional clamp on 24 V auxiliary input feeding isolated flyback or buck converter. Use Value: Limits clamped voltage to 33.2 V, ensuring secondary-side 5 V/12 V regulators remain within safe operating area. |
| ADAS Camera Module | Electric Power Steering (EPS) |
Use Scenario: Guards image sensor and serializer power inputs against ESD and cable discharge events. IC Role / Device Role / Timing Role: Localized TVS at FAKRA connector interface, placed before LDOs powering CIS and SerDes ICs. Use Value: Withstands ±30 kV contact discharge (ISO 10605) without degradation, preserving signal integrity in GMSL links. |
Use Scenario: Protects motor driver gate drivers and MCU power rails from inductive kickback during steering actuation. IC Role / Device Role / Timing Role: Primary surge clamp on 24 V motor supply bus upstream of half-bridge drivers. Use Value: Delivers 1250 W surge capability at Tj = 150 °C, sustaining repeated Pulse 3b (+150 V) events in EPS control units. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ24A | Lower peak power (400 W), higher VCL (38.9 V), non-AEC-Q101 | Limited to non-automotive industrial use; insufficient for ISO 7637-2 Pulse 3a | Select only for cost-sensitive non-automotive 24 V systems with lower surge severity |
| SMBJ24A | 600 W peak power, VCL = 38.9 V, AEC-Q101 not claimed | Marginally suitable for ISO 7637-2 Pulse 1/2a but fails Pulse 3a/3b compliance | Acceptable only if full ISO 7637-2 coverage is not required and Tj < 125 °C |
Compared with SMAJ24A and SMBJ24A, the SM15T24AY delivers 2.5× higher peak power, 5.7 V lower clamping voltage, and certified AEC-Q101 reliability-making it the only choice for production automotive 24 V front-end protection requiring full ISO 7637-2 and ISO 10605 compliance.
Availability
SM15T24AY is available at Aetrix Electronics and suitable for automotive body control modules, ADAS camera power interfaces, and electric power steering systems requiring stable component supply across extended temperature and lifecycle demands.
Supply support for SM15T24AY 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, specializing in automotive, industrial, and power discrete technologies with over 40 years of analog and protection device innovation.
The SM15TxxAY series belongs to ST's automotive-qualified TVS portfolio, engineered specifically for robust transient immunity in 12 V/24 V vehicle electrical architectures-including start-stop, 48 V mild hybrid, and zonal E/E systems.
FAQ
What is the maximum clamping voltage of SM15T24AY under a 10/1000 µs surge?
The SM15T24AY clamps to 33.2 V at 45 A under a 10/1000 µs waveform, verified per IEC 61000-4-5 testing conditions. This value is measured at Tj = 25 °C and remains ≤35.1 V at Tj = 150 °C due to its 9.4 × 10−4/°C temperature coefficient.
Does SM15T24AY meet ISO 7637-2 for 24 V battery systems?
Yes-SM15T24AY is validated for all four ISO 7637-2 pulses applicable to 24 V systems: Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), and Pulse 3b (+150 V). Its 1500 W rating and low RD ensure compliance without external derating.
How does the SMC package affect thermal performance in PCB layout?
The SMC package achieves Rth(j-a) ≈ 120 °C/W with 3.14 cm² copper area per lead, per JEDEC JESD51-3. Layout must follow ST's recommended footprint (8.19 mm × 5.11 mm pad pitch) and avoid solder mask dams to maintain thermal conduction to inner layers.
Is SM15T24AY compatible with lead-free reflow processes?
Yes-SM15T24AY is RoHS-compliant and qualified for lead-free reflow per IPC/JEDEC J-STD-020, with peak profile up to 245 °C for ≤30 seconds. ST recommends minimizing convection airflow during reflow to prevent component movement on the SMC footprint.
SM15T24AY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AB, SMC
- Series:
- SM15TY, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 20.5V
- Voltage - Breakdown (Min):
- 22.8V
- Voltage - Clamping (Max) @ Ipp:
- 42.8V
- Current - Peak Pulse (10/1000µs):
- 234A (8/20µs)
- Power - Peak Pulse:
- 1500W (1.5kW)
- 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:
- SMC
SM15T24AY FAQ
1.How can I place an order for SM15T24AY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM15T24AY 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 SM15T24AY reliable?
The price and inventory of SM15T24AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM15T24AY is usually 5 days.
3.What payment methods are accepted for SM15T24AY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM15T24AY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM15T24AY?
SM15T24AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM15T24AY 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 SM15T24AY?
For technical support, including SM15T24AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM15T24AY requirements.
6.How does Aetrix verify that SM15T24AY is sourced from the original manufacturer or authorized distributors?
All SM15T24AY 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 SM15T24AY meets industry standards.
7.What is the process for return or replacement of SM15T24AY?
All SM15T24AY units undergo pre-shipment inspection (PSI). If there is an issue with SM15T24AY, 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 SM15T24AY part is unused and in its original packaging.
Return procedure for SM15T24AY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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