Vishay General Semiconductor - Diodes Division P4SMA15AHM3_A/H

Overview

P4SMA15AHM3_A/H from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode designed for clamping inductive switching transients and ESD events on power rails and signal lines. It features a 15 V breakdown voltage (V_BR = 14.3–15.8 V at 1 mA), 12.8 V stand-off voltage (V_WM), 21.2 V maximum clamping voltage (V_C) at 18.9 A peak pulse current, and 400 W peak pulse power rating with 10/1000 µs waveform. It is AEC-Q101 qualified and housed in SMA (DO-214AC) package for automotive and industrial power rail protection.

For engineers reviewing the P4SMA15AHM3_A/H datasheet, P4SMA15AHM3_A/H pinout, P4SMA15AHM3_A/H application, or P4SMA15AHM3_A/H equivalent, this device is selected for robust overvoltage protection where low clamping ratio, fast response (<1 ns), and halogen-free RoHS compliance are required - especially in 12 V automotive subsystems, DC-DC converter inputs, and sensor interface lines subject to load dump or ISO 7637-2 pulses.

Technical Context

The P4SMA15AHM3_A/H operates as a unidirectional avalanche diode, conducting only when reverse voltage exceeds its breakdown threshold (V_BR), thereby shunting surge energy to ground while limiting downstream voltage to ≤21.2 V. Its glass-passivated junction ensures stable V_BR tolerance (±5%) and low leakage (<1 µA at 12.8 V).

Thermally, it exhibits R_θJA = 120 °C/W and R_θJL = 30 °C/W, enabling reliable operation up to T_J = 150 °C. It meets MSL Level 1 per J-STD-020 and supports reflow soldering with peak temperature of 260 °C.

Key Specifications

Pinout & Package

Package: SMA (DO-214AC), surface-mount, halogen-free, matte tin-plated leads, compliant with J-STD-002 and JESD 22-B102 solderability standards. Cathode indicated by band on body.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transient voltage suppression applications.

Compared with SMAJ15A-E3/5A and 1.5SMC15A, the P4SMA15AHM3_A/H uniquely combines AEC-Q101 qualification, halogen-free construction, and optimized thermal performance in the compact SMA footprint - making it the preferred choice for space-constrained automotive electronics where regulatory compliance and long-term reliability are mandatory.

Availability

P4SMA15AHM3_A/H is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC I/O protection, and DC-DC converter input stages requiring stable component supply, full traceability, and lifecycle continuity.

Supply support for P4SMA15AHM3_A/H 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

Vishay General Semiconductor is a global leader in discrete semiconductors, specializing in diodes, rectifiers, TVS devices, and power MOSFETs with emphasis on high-reliability and automotive-grade solutions.

The P4SMA Series is engineered for robust transient suppression in harsh environments, targeting automotive, industrial, and telecom applications where fast response, low clamping, and qualification-grade reliability are critical.

FAQ

What is the maximum clamping voltage of the P4SMA15AHM3_A/H under a 10/1000 µs surge?

The P4SMA15AHM3_A/H has a maximum clamping voltage (V_C) of 21.2 V when subjected to its rated peak pulse current of 18.9 A using the standardized 10/1000 µs waveform. This value is measured per JEDEC standards and reflects the actual voltage imposed on the protected circuit during worst-case transient events, ensuring downstream components remain within safe operating limits. The P4SMA15AHM3_A/H achieves this with a clamping ratio of approximately 1.41 relative to its nominal breakdown voltage.

Is the P4SMA15AHM3_A/H suitable for automotive applications?

Yes, the P4SMA15AHM3_A/H is explicitly AEC-Q101 qualified, as confirmed by its HM3 suffix and documentation in Vishay's P4SMA series datasheet (Rev. 09-Jan-2024). It undergoes rigorous stress testing including temperature cycling, highly accelerated life testing (HALT), and ESD verification - making it suitable for under-hood and cabin-mounted automotive electronics such as body control modules, infotainment power supplies, and ADAS camera power rails. The P4SMA15AHM3_A/H also complies with MSL Level 1 and supports 260 °C peak reflow.

What does the "HM3" suffix indicate in P4SMA15AHM3_A/H?

The "HM3" suffix in P4SMA15AHM3_A/H denotes halogen-free, RoHS-compliant construction combined with AEC-Q101 qualification. Specifically, "H" indicates halogen-free molding compound, "M3" confirms RoHS compliance and JESD201 Class 2 whisker resistance, and the "_A/H" revision code specifies packaging in 7-inch tape-and-reel format (1800 units per reel). This distinguishes it from commercial-grade variants like E3 or M3 without automotive qualification. The P4SMA15AHM3_A/H thus meets both environmental and automotive reliability mandates simultaneously.

How does the P4SMA15AHM3_A/H compare to bidirectional TVS diodes?

The P4SMA15AHM3_A/H is unidirectional and intended for DC power line protection where polarity is fixed - e.g., 12 V supply rails with defined anode/cathode orientation. Unlike bidirectional types (e.g., P4SMA15CA), it blocks forward current above ~1.2 V and conducts only in reverse avalanche mode. This yields lower leakage and tighter V_BR tolerance than bidirectional equivalents. For AC or floating signal lines, a bidirectional variant would be required; the P4SMA15AHM3_A/H is not interchangeable in those roles due to polarity dependence.

What is the thermal resistance of the P4SMA15AHM3_A/H, and how does it affect layout design?

The P4SMA15AHM3_A/H has a typical junction-to-ambient thermal resistance (R_θJA) of 120 °C/W and junction-to-lead resistance (R_θJL) of 30 °C/W, measured on standard 0.2" × 0.2" copper pads. To maintain T_J ≤ 150 °C under repetitive surges, PCB layout must provide adequate copper area and minimize trace length to thermal vias. Derating curves in the datasheet show >50% power reduction above 25 °C ambient - so the P4SMA15AHM3_A/H requires careful thermal design in enclosed or high-temperature enclosures.