My Inquiry
My Account
STMicroelectronics SM50T26AY
- Part No.:
- SM50T26AY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM50T26AY.pdf
- Description:
- AUTOMOTIVE 5000 W, 22 V TVS IN S
- Quantity:
- Payment:
- Shipping:
Inventory:2,450
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SM50T26AY from STMicroelectronics is an AEC-Q101-qualified unidirectional automotive TVS diode in SMC package, designed to clamp transient surges up to 5000 W (10/1000 µs) and 48 kW (8/20 µs), with a standoff voltage (VRM) of 22 V, breakdown voltage (VBR) of 24.4–27.0 V at 1 mA, and clamping voltage (VCL) of 35.5 V at 141 A. It protects 12 V automotive power rails against ISO 7637-2 pulses (Pulse 1: −150 V; Pulse 2a: +112 V; Pulse 3a: −220 V; Pulse 3b: +150 V) and meets ISO 10605 ESD immunity (±30 kV contact/air).
For engineers reviewing the SM50T26AY datasheet, SM50T26AY pinout, SM50T26AY application, or SM50T26AY equivalent, this device is selected for high-reliability automotive front-end protection where low leakage (0.2 µA at 25 °C), high junction temperature operation (up to +175 °C), and JEDEC-registered SMC footprint compatibility are critical.
Technical Context
The SM50T26AY uses planar silicon avalanche technology to achieve stable breakdown characteristics over temperature (αT = 10 × 10⁻⁴ /°C), enabling predictable clamping across −55 °C to +175 °C operating range. Its dynamic resistance (RD = 26.1 mΩ) ensures minimal voltage overshoot during fast transients like ISO 7637-2 Pulse 3b.
It complies with IEC 61000-4-2 (±30 kV ESD), ISO 10605 (±30 kV), and ISO 7637-2 (Pulse 1, 2a, 3a, 3b), and supports load dump immunity per ISO 16750-2 Test B (Us = 87 V, td = 150/400 ms) when used with appropriate series impedance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRM) | 22 V - Maximum continuous reverse operating voltage before significant leakage; sets minimum system rail margin. |
| Breakdown Voltage (VBR) | 24.4–27.0 V at 1 mA - Confirmed avalanche onset range; defines turn-on threshold under surge conditions. |
| Clamping Voltage (VCL) | 35.5 V at 141 A (8/20 µs) - Peak voltage seen by protected circuit during worst-case surge; determines downstream IC survivability. |
| Peak Pulse Power (PPP) | 5000 W (10/1000 µs) - Sustained energy-handling capability for slow transients like load dump simulations. |
| Leakage Current (IRM) | 0.2 µA at 25 °C - Ultra-low reverse leakage preserves battery life and avoids false triggers in always-on automotive modules. |
| Junction Temperature Range | −55 °C to +175 °C - Enables placement near hot engine compartments or power electronics without derating. |
| Package | SMC (DO-214AB) - JEDEC-registered surface-mount outline with 7.75–8.15 mm width; compatible with IPC-7531 footprints. |
Pinout & Package
SM50T26AY is a two-terminal unidirectional TVS diode in SMC (DO-214AB) package. Cathode is marked by a bar on the body; anode and cathode terminals are arranged in a single-row gull-wing configuration suitable for automated PCB assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (A) | Low-side connection point | Connected to ground or low-impedance return path; completes clamping loop during negative transients (e.g., ISO 7637-2 Pulse 1). |
| Cathode (K) | High-side connection point | Connected to protected line (e.g., 12 V battery rail); conducts avalanche current during overvoltage events to clamp voltage below system tolerance. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive under-hood use with extended temperature cycling, humidity, and mechanical shock testing. |
| Low dynamic resistance (26.1 mΩ) | Minimizes clamping voltage rise under high-current transients, improving protection margin for 3.3 V/5 V downstream logic. |
| Planar junction technology | Delivers stable VBR temperature coefficient (αT = 10 × 10⁻⁴ /°C) and long-term reliability in high-Tj environments. |
| UL94 V0 flammability rating | Ensures flame-retardant epoxy housing meets automotive cabin and engine bay safety requirements. |
| JEDEC MSL Level 1 | Zero moisture sensitivity - can be stored indefinitely at ambient conditions without baking prior to reflow. |
Applications
| Engine Control Unit (ECU) Power Input | Body Control Module (BCM) CAN Bus Protection |
|---|---|
|
Use Scenario: Protects 12 V input rail of engine control units exposed to alternator load dump and cranking transients. IC Role / Device Role / Timing Role: Unidirectional shunt clamping device placed directly at ECU power entry point to limit voltage excursions below 36 V. Use Value: Prevents damage to MCU power supplies and analog front-ends during ISO 7637-2 Pulse 5b (load dump) with Us = 87 V and td = 400 ms. |
Use Scenario: Shields CAN transceivers in body control modules from coupled transients on shared 12 V supply lines. IC Role / Device Role / Timing Role: Secondary-level TVS placed upstream of CAN bus power conditioning to suppress common-mode surges before they reach isolated DC/DC converters. Use Value: Maintains CAN signal integrity by limiting supply rail overshoot to ≤35.5 V during ISO 7637-2 Pulse 3b (+150 V), preventing transceiver latch-up. |
| Advanced Driver Assistance Systems (ADAS) Camera Power | Electric Power Steering (EPS) Motor Driver Supply |
|
Use Scenario: Safeguards image sensor and ISP power rails in automotive cameras mounted near engine compartments. IC Role / Device Role / Timing Role: Primary overvoltage protector on 12 V input, operating continuously at Tj up to +175 °C with <0.2 µA leakage. Use Value: Ensures uninterrupted camera operation during repeated cold-cranking pulses (ISO 16750-2 Test B) without thermal runaway or parametric drift. |
Use Scenario: Clamps voltage spikes induced by H-bridge switching and motor back-EMF in EPS systems. IC Role / Device Role / Timing Role: Fast-response shunt device on main 12 V supply rail feeding gate drivers and current sense amplifiers. Use Value: Limits transient-induced gate oxide stress on MOSFET drivers by clamping to 35.5 V within nanoseconds, preserving FET lifetime. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional automotive TVS applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ24A | Lower PPP (400 W), higher VCL (43.5 V at 92 A), SMA package (smaller thermal mass) | Not qualified to AEC-Q101; limited to non-safety-critical infotainment or lighting modules | Select only for cost-sensitive, low-energy surges where 175 °C operation and ISO 7637-2 compliance are not required. |
| 1.5KE27A | Higher VRM (23.1 V), same VBR range, axial leaded DO-201 package, no AEC-Q101 qualification | Requires through-hole mounting; unsuitable for automated SMT lines or vibration-prone locations | Use only for legacy board redesigns where SMC footprint change is prohibited and automotive qualification is waived. |
Compared with SMAJ24A and 1.5KE27A, SM50T26AY delivers 12.5× higher peak pulse power, guaranteed AEC-Q101 reliability, and SMC-compatible thermal performance - making it the sole choice for new automotive power rail designs requiring ISO 7637-2 Pulse 1–3b and load dump immunity.
Availability
SM50T26AY is available at Aetrix Electronics and suitable for engine control units, body control modules, ADAS camera power systems, and electric power steering supply rails requiring stable component supply across automotive production lifecycles.
Supply support for SM50T26AY 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 management solutions with vertical manufacturing capabilities.
SM50T26AY belongs to the SM50TY series of high-power automotive TVS diodes, engineered specifically for robust transient suppression in 12 V and 24 V vehicle electrical architectures compliant with ISO 7637-2, ISO 10605, and ISO 16750.
FAQ
What is the maximum clamping voltage of SM50T26AY under an 8/20 µs surge?
The maximum clamping voltage (VCL) of SM50T26AY is 35.5 V at 141 A for an 8/20 µs waveform, measured at Tamb = 25 °C. This value increases linearly with junction temperature at αT = 10 × 10⁻⁴ /°C, reaching ~37.2 V at Tj = 150 °C per the datasheet's VCL vs. Tj formula.
Is SM50T26AY suitable for bidirectional signal line protection?
No - SM50T26AY is a unidirectional TVS diode intended for DC power rail protection only. For bidirectional signal lines such as CAN or LIN buses, ST offers the complementary SM50T26CAY variant, which features symmetrical clamping in both polarities and identical surge ratings.
Does SM50T26AY require external heat sinking in standard automotive PCB layouts?
No external heatsink is required. When mounted on a 4-layer FR4 PCB with 1.54 mm × 5.11 mm copper pads per lead (per Figure 24), its thermal resistance junction-to-ambient is ~120 °C/W, allowing full 5000 W pulse handling at Tj ≤ 175 °C without auxiliary cooling.
How does SM50T26AY differ from SM50T26CAY beyond polarity?
SM50T26CAY has identical electrical ratings (VRM, VBR, VCL, PPP) but uses a center-tapped symmetrical structure for bidirectional clamping. Its marking differs (EBOY vs. EBOY with cathode bar omitted), and its junction capacitance is ~2× higher (~120 pF vs. ~60 pF at 1 V) due to dual-junction layout - a key consideration for high-speed data lines.
SM50T26AY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AB, SMC
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 22V (Max)
- Voltage - Breakdown (Min):
- 24.4V
- Voltage - Clamping (Max) @ Ipp:
- 35.5V
- Current - Peak Pulse (10/1000µs):
- 141A
- Power - Peak Pulse:
- 5000W (5kW)
- 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:
- SMC
SM50T26AY FAQ
1.How can I place an order for SM50T26AY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM50T26AY 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 SM50T26AY reliable?
The price and inventory of SM50T26AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM50T26AY is usually 5 days.
3.What payment methods are accepted for SM50T26AY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM50T26AY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM50T26AY?
SM50T26AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM50T26AY 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 SM50T26AY?
For technical support, including SM50T26AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM50T26AY requirements.
6.How does Aetrix verify that SM50T26AY is sourced from the original manufacturer or authorized distributors?
All SM50T26AY 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 SM50T26AY meets industry standards.
7.What is the process for return or replacement of SM50T26AY?
All SM50T26AY units undergo pre-shipment inspection (PSI). If there is an issue with SM50T26AY, 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 SM50T26AY part is unused and in its original packaging.
Return procedure for SM50T26AY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM50T26AY Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
-
D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
-
D5V0L1B2WS-7
Diodes Incorporated
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
