STMicroelectronics SM6T6V8CAY

Overview

SM6T6V8CAY from STMicroelectronics is a bidirectional automotive-grade transient voltage suppression (TVS) diode in SMB package, designed for ISO 7637-2 pulse protection and IEC 61000-4-2 ESD immunity in 12 V vehicle electronics. It features a 6.8 V standoff voltage (VRM), 10.5 V clamping voltage at 57 A (10/1000 µs), 600 W peak pulse power, and <0.2 µA leakage at 25 °C - enabling robust surge resilience in engine control units and body electronics.

For engineers reviewing the SM6T6V8CAY datasheet, SM6T6V8CAY pinout, SM6T6V8CAY application, or SM6T6V8CAY equivalent, key selection criteria include bidirectional polarity, low dynamic resistance (0.027 Ω), high junction temperature rating (150 °C), and compliance with ISO 10605 ±30 kV (air/contact discharge) and ISO 7637-2 Pulse 1/2a/3a/3b waveforms.

Technical Context

This bidirectional TVS diode employs planar silicon technology to achieve stable breakdown behavior across temperature (αT = 5.7 × 10⁻⁴ /°C), low leakage (<1 µA up to 85 °C), and high surge capability even at Tj = 150 °C (515 W, 10/1000 µs). Its symmetrical VBR min/max (5.80 V / 7.14 V) ensures consistent clamping in both polarities during transients.

The device meets AEC-Q101 qualification and supports automotive-grade reliability requirements including JESD22-B102 E3 solderability, IPC7531 footprint compatibility, and JEDEC-standard SMB outline. Its 0.027 Ω dynamic resistance enables fast response to 8/20 µs surges (IPP = 275 A) while limiting voltage overshoot during load dump events.

Key Specifications

Pinout & Package

The SM6T6V8CAY is housed in an SMB (DO-214AA) surface-mount package with two terminals: Cathode (K) and Anode (A), arranged symmetrically for bidirectional operation. The package measures 3.30–3.95 mm (D) × 5.10–5.60 mm (E) × 1.90–2.45 mm (A1) and uses matte tin-plated leads compliant with J-STD-002 and MIL-STD-750 Method 2026.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ6.8CA and 1.5KE6.8CA, SM6T6V8CAY delivers superior automotive readiness via AEC-Q101, tighter VBR tolerance (±5%), lower clamping voltage (10.5 V vs. ≥11.5 V), and optimized thermal performance for high-density layouts - making it the preferred choice for production automotive ECUs.

Availability

SM6T6V8CAY is available at Aetrix Electronics and suitable for engine control units, body control modules, infotainment power supplies, and ADAS camera interfaces requiring stable component supply across automotive production lifecycles.

Supply support for SM6T6V8CAY 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 45 years of innovation in silicon-based protection devices.

The SM6TY series was developed specifically for automotive electronics protection, targeting ISO 7637-2 and ISO 10605 compliance in space-constrained SMB footprints while maintaining high-temperature reliability and low leakage.

FAQ

What does the 'CAY' suffix indicate in SM6T6V8CAY?

The 'CAY' suffix denotes a bidirectional configuration ('C'), automotive grade ('A'), and tape-and-reel packaging ('Y'). Unlike 'AY' unidirectional variants, 'CAY' devices provide symmetrical clamping for both positive and negative transients - critical for data line and dual-rail protection in automotive networks.

How does SM6T6V8CAY differ from SM6T6V8AY?

SM6T6V8CAY is bidirectional with symmetrical VBR (5.80–7.14 V) and clamping in both polarities, while SM6T6V8AY is unidirectional and only clamps reverse-polarity surges. The 'CAY' version has identical electrical specs except for polarity behavior and is marked 'LEY' versus 'DEY' for the unidirectional variant.

Can SM6T6V8CAY be used in 24 V commercial vehicle systems?

No - its 6.8 V standoff voltage is designed for 12 V nominal automotive systems. For 24 V applications, ST recommends SM6T12CAY (12 V VRM) or SM6T24CAY (24 V VRM), which maintain appropriate margin above system voltage while meeting ISO 7637-2 Pulse 1 (–150 V) and Pulse 2a (+112 V) requirements.

Is the SMB package of SM6T6V8CAY compatible with standard reflow profiles?

Yes - it follows J-STD-020 MSL level 1 and ST's recommended reflow profile: peak temperature 240–245 °C for 60–90 seconds, ramp rates ≤3 °C/s, and cooling rate ≥2 °C/s. Matte tin plating ensures reliable solder joint formation on FR4 PCBs with 70 µm copper thickness.