Vishay General Semiconductor - Diodes Division P4SMA300AHM3_A/I

Overview

P4SMA300AHM3_A/I from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode in SMA (DO-214AC) package, rated for 300 V standoff voltage (VWM), 315 V minimum breakdown voltage (VBR), and 400 W peak pulse power (10/1000 µs). It provides robust overvoltage protection for DC power rails and signal lines in automotive and industrial control systems.

For engineers reviewing the P4SMA300AHM3_A/I datasheet, P4SMA300AHM3_A/I pinout, P4SMA300AHM3_A/I application, or P4SMA300AHM3_A/I equivalent, key selection criteria include clamping voltage at rated surge current, AEC-Q101 qualification status, thermal resistance (R_θJA = 120 °C/W), and halogen-free RoHS compliance per HM3 suffix.

Technical Context

This device operates as a unidirectional avalanche diode, conducting only during reverse overvoltage events above its breakdown threshold. Its glass-passivated junction ensures stable VBR tolerance (±5%) and low leakage (<1 µA at VWM), with fast response time <1 ns to suppress transients induced by inductive switching or ESD.

Designed for mounting on 5.0 mm × 5.0 mm copper pads, it delivers 400 W peak pulse power up to TA = 25 °C, derating linearly above that temperature per Figure 2. The cathode band identifies polarity, and it meets MSL Level 1 per J-STD-020 with 260 °C reflow peak.

Key Specifications

Pinout & Package

Package: SMA (DO-214AC), surface-mount, halogen-free, RoHS-compliant, matte tin-plated leads. Cathode identified by black band.

Key Features

Applications

Equivalent & Alternatives

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

Compared with P4SMA300AHM3_A/I, SMAJ300A-E3/5A offers identical electrical protection but lacks automotive qualification and has marginally higher thermal resistance, while 1.5SMC300AHE3_A provides triple the pulse power in a larger package-making P4SMA300AHM3_A/I optimal for space-constrained AEC-Q101 designs needing precise 300 V standoff.

Availability

P4SMA300AHM3_A/I is available at Aetrix Electronics and suitable for automotive body electronics, industrial programmable logic controllers, and telecom power supply protection requiring stable component supply, halogen-free compliance, and AEC-Q101 validation.

Supply support for P4SMA300AHM3_A/I 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, MOSFETs, optoelectronics, and passive components with emphasis on reliability and application-specific performance.

The P4SMA Series targets cost-sensitive, high-volume transient suppression in automotive, industrial, and telecom systems-designed for automated placement, high surge robustness, and compatibility with lead-free reflow processes.

FAQ

What is the maximum clamping voltage of P4SMA300AHM3_A/I at its rated peak pulse current?

The P4SMA300AHM3_A/I has a maximum clamping voltage (VC) of 414 V at its rated peak pulse current (IPPM) of 0.73 A under the standard 10/1000 µs waveform. This value is measured per Figure 1 and Table on page 2 of the Vishay datasheet 88367, and defines the upper voltage limit imposed on protected circuits during worst-case transient events. The P4SMA300AHM3_A/I maintains this clamping performance across its specified operating temperature range.

Is P4SMA300AHM3_A/I qualified for automotive applications?

Yes, P4SMA300AHM3_A/I is AEC-Q101 qualified, as confirmed by the "HM3" suffix and documentation in the Vishay P4SMA Series datasheet (Rev. 09-Jan-2024, Doc. #88367). The HM3 designation indicates halogen-free, RoHS-compliant construction with full AEC-Q101 stress testing-including temperature cycling, highly accelerated life testing (HALT), and ESD verification. This makes P4SMA300AHM3_A/I suitable for under-hood and chassis-mounted automotive modules.

What does the "_A/I" suffix mean in P4SMA300AHM3_A/I?

The "_A/I" suffix in P4SMA300AHM3_A/I denotes two specific attributes: "A" indicates the revision level (Revision A per ordering table footnote 2), and "I" specifies the packaging format-7500-piece tape-and-reel on 13-inch diameter reels (per Ordering Information table, page 3 of datasheet 88367). This distinguishes it from "H"-coded variants (1800-piece reels on 7-inch diameter reels) and confirms full traceability and compliance with Vishay's material categorization standards.

How does the thermal resistance of P4SMA300AHM3_A/I affect PCB layout?

P4SMA300AHM3_A/I has a typical junction-to-ambient thermal resistance (R_θJA) of 120 °C/W, measured on 5.0 mm × 5.0 mm copper pads per datasheet Figure 2. To maintain safe junction temperatures during repetitive surges, PCB layout must allocate sufficient copper area-minimum 0.2" × 0.2" (5.0 mm × 5.0 mm) per terminal-and avoid thermal isolation. Reducing pad size or using thin copper increases R_θJA, risking thermal runaway during sustained transient activity. The P4SMA300AHM3_A/I datasheet explicitly ties derating curves to this pad geometry.

Can P4SMA300AHM3_A/I be used in bidirectional configurations?

No, P4SMA300AHM3_A/I is a unidirectional TVS diode, as indicated by the "A" (not "CA") suffix and absence of bidirectional VBR/VWM ranges in its electrical characteristics table. Bidirectional variants use the "CA" suffix (e.g., P4SMA300CA), which provide symmetrical clamping in both polarities. Using P4SMA300AHM3_A/I in bidirectional applications would leave positive-going transients unprotected. Always verify polarity designation in the part number and consult the P4SMA300AHM3_A/I datasheet Table on page 2 for confirmed unidirectional parameters.