STMicroelectronics SM15T36A

Overview

SM15T36A from STMicroelectronics is a unidirectional 1500 W transient voltage suppression diode in SMC package, designed for IEC 61000-4-2 ESD (30 kV air/contact) and IEC 61000-4-4 surge (4 kV level 4) protection of DC power rails and signal lines. It features 36 V standoff voltage (VRM), 49.9 V clamping voltage at 30 A (10/1000 µs), and 0.2 µA leakage at 25 °C - enabling robust overvoltage protection in high-reliability industrial power supplies and telecom interfaces.

For engineers reviewing the SM15T36A datasheet, SM15T36A pinout, SM15T36A application, or SM15T36A equivalent, key selection criteria include clamping voltage vs. surge current (VCL = 49.9 V @ IPP = 30 A), thermal derating above 25 °C (Tj max = 150 °C), low dynamic resistance (RD = 0.403 Ω), and compatibility with FR4 PCB footprints per IPC7531.

Technical Context

The SM15T36A operates as a planar-junction avalanche diode, triggering at breakdown voltage (VBR min = 30.8 V) to clamp transients while maintaining low leakage (<0.2 µA at VRM). Its unidirectional polarity enables asymmetric protection on positive-rail applications without reverse conduction path.

Clamping performance is defined by VCL–IPP relationship (49.9 V @ 30 A, 10/1000 µs) and dynamic resistance (RD = 0.403 Ω), enabling predictable voltage limiting under fast surges. Thermal design relies on junction-to-ambient Rth(j-a) ≤ 120 °C/W on recommended copper area (≥3.14 cm²), supporting continuous operation up to 150 °C junction temperature.

Key Specifications

Pinout & Package

SM15T36A uses the industry-standard SMC (DO-214AB) surface-mount package: 7.75–8.15 mm length × 5.55–6.25 mm width × 2.45 mm height, with matte tin-plated leads compliant with J-STD-002 and RoHS. Recommended footprint matches IPC7531 outline with 8.19 mm pad centerline spacing.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar TVS diode applications.

Compared with SMBJ36A and P6SMB36A, SM15T36A delivers superior surge energy handling (1500 W vs. 600 W), tighter clamping (49.9 V vs. ≥58.1 V), and lower dynamic resistance - making it the optimal choice for high-reliability industrial and telecom systems demanding strict voltage ceilings.

Availability

SM15T36A is available at Aetrix Electronics and suitable for industrial power supply input protection, telecom line interface protection, automotive body control module power rails, and AC-DC adapter secondary-side protection requiring stable component supply and full IEC 61000-4-2/4-4 compliance.

Supply support for SM15T36A 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, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.

The SM15T series belongs to ST's high-power TVS diode product line, engineered specifically for robust electrostatic and surge protection in mission-critical power and interface circuits where low leakage, tight clamping, and high-temperature reliability are mandatory.

FAQ

What is the maximum surge current SM15T36A can handle at 10/1000 µs?

SM15T36A supports a peak pulse current (IPP) of 30 A under the 10/1000 µs waveform, corresponding to its 1500 W peak pulse power rating at 25 °C ambient. At elevated junction temperatures (e.g., 150 °C), this derates to approximately 25 A due to reduced thermal headroom, as confirmed by Figure 3 in DS0683 Rev 8.

Does SM15T36A meet automotive qualification standards?

SM15T36A is not AEC-Q200 qualified, though it meets IEC 61000-4-2 (30 kV ESD), IEC 61000-4-4 (4 kV surge), and UL 497B for telecom safety. For automotive applications, it is commonly used in non-safety-critical body electronics (e.g., BCM power rails) where customer-specific validation replaces formal AEC-Q200 testing.

How does the 0.2 µA leakage current impact low-power IoT sensor nodes?

At 0.2 µA @ 25 °C and VRM = 36 V, SM15T36A adds negligible current draw to battery-powered sensor nodes - less than 0.1% of typical 200 µA sleep-mode MCU current. Leakage remains below 1 µA even at 125 °C, preserving multi-year battery life in edge devices deployed in hot enclosures.

Can SM15T36A be used in bidirectional signal line protection?

No - SM15T36A is unidirectional (A suffix) and conducts only in reverse bias. For bidirectional signal lines (e.g., RS-485, CAN), the SM15T36CA variant must be used. Using SM15T36A on AC-coupled or symmetric signals risks forward conduction and unintended clamping during normal operation.