STMicroelectronics SM15T82CAY

Overview

SM15T82CAY from STMicroelectronics is a bidirectional automotive-grade transient voltage suppressor (TVS) diode in SMC package, designed for ISO 7637-2 pulse protection in 12 V/24 V vehicle systems. It features a nominal breakdown voltage of 82 V, clamping voltage of 113 V at 13.9 A (10/1000 µs), peak pulse power of 1500 W, and operates up to 150 °C junction temperature - deployed in engine control units, body control modules, and infotainment power rails.

For engineers reviewing the SM15T82CAY datasheet, SM15T82CAY pinout, SM15T82CAY application, or SM15T82CAY equivalent, key selection criteria include bidirectional surge capability against ISO 10605 ±30 kV ESD, low leakage current (0.2 µA at 25 °C), dynamic resistance of 0.87 Ω, and compliance with AEC-Q101 for under-hood reliability.

Technical Context

This TVS uses planar silicon technology to achieve stable high-temperature operation (Tj max = 150 °C) and low leakage (<1 µA at 85 °C), critical for long-life automotive electronics. Its bidirectional configuration enables symmetric clamping during both positive and negative transients - essential for protecting CAN/LIN bus lines and sensor interfaces exposed to load dump or inductive switching.

The device meets IEC 61000-4-4 level 4 (±4 kV), exceeds ISO 10605 level 4 (±30 kV air/contact discharge), and withstands ISO 7637-2 pulses including Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), and Pulse 3b (+150 V) - all without derating below 1250 W peak power at Tj = 150 °C.

Key Specifications

Pinout & Package

SM15T82CAY is housed in an SMC (DO-214AB) surface-mount package with two terminals: Cathode and Anode arranged in a symmetrical bidirectional layout. The package complies with JEDEC registered outline and IPC7531 footprint, featuring matte tin-plated leads rated for 260 °C soldering (10 s).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ85CA and SMBJ85CA, SM15T82CAY uniquely combines AEC-Q101 qualification, 1500 W pulse rating, and SMC footprint - making it the only option certified for direct integration into ISO 26262 ASIL-B power domains without additional derating or external thermal management.

Availability

SM15T82CAY is available at Aetrix Electronics and suitable for engine control units, body control modules, and ADAS camera modules requiring stable component supply across extended automotive production lifecycles.

Supply support for SM15T82CAY 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 ICs with vertical manufacturing capabilities.

The SM15Txx series belongs to ST's automotive-grade TVS portfolio, engineered specifically to meet stringent ISO 7637-2 and ISO 10605 requirements for next-generation vehicle electronics.

FAQ

What is the maximum clamping voltage of SM15T82CAY under a 10/1000 µs surge?

The maximum clamping voltage is 113 V at 13.9 A for a 10/1000 µs waveform, measured at Tj = 25 °C. This value increases by 10.5 × 10⁻⁴ per °C above 25 °C due to the αT coefficient, reaching ~120 V at Tj = 150 °C - verified per DS6928 Table 2 and Figure 5.

Is SM15T82CAY compatible with lead-free reflow soldering processes?

Yes - it supports standard Pb-free reflow per JEDEC J-STD-020 MSL Level 1, with peak temperature up to 245 °C for ≤30 seconds. The matte tin-plated leads pass JESD 22-B102 E3 and MIL-STD-750 Method 2026 tests, and the recommended profile includes ramp rates of ≤3 °C/s and soak at 150–200 °C for 60–90 seconds.

How does SM15T82CAY differ from unidirectional SM15T82AY in circuit implementation?

SM15T82CAY provides symmetrical clamping for both polarities and connects across floating or differential lines (e.g., LIN bus), whereas SM15T82AY must be oriented with cathode toward the protected rail and only clamps positive transients. Their marking differs (BFRY vs. MFRY), and CAY requires no polarity-aware layout - reducing design error risk in high-volume automotive PCBs.

Can SM15T82CAY replace SMA6J85A in an existing design?

No - SMA6J85A is unidirectional with 600 W rating and DO-214AC package, lacking AEC-Q101 qualification and ISO 7637-2 Pulse 1/3a capability. Substituting it with SM15T82CAY requires verifying PCB footprint compatibility (SMC vs. SMA), updating schematic polarity symbols, and validating thermal performance under 1500 W pulses - not a drop-in replacement.