Vishay General Semiconductor - Diodes Division P6SMB440AHM3_C/I

Overview

P6SMB440AHM3_C/I from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode in the P6SMB series, designed for high-energy surge protection on DC power rails and signal lines. It features a 440 V standoff voltage (VWM), 462 V maximum breakdown voltage (VBR), 600 W peak pulse power rating (10/1000 μs), and clamps transients to 602 V at 1 A peak pulse current - deployed in industrial motor drives and telecom power supplies.

For engineers reviewing the P6SMB440AHM3_C/I datasheet, P6SMB440AHM3_C/I pinout, P6SMB440AHM3_C/I application, or P6SMB440AHM3_C/I equivalent, key selection criteria include verified clamping voltage under 602 V, unidirectional polarity with cathode band marking, SMB (DO-214AA) package compatibility, and AEC-Q101 qualification status for automotive-grade reliability validation.

Technical Context

This TVS diode operates as a voltage-clamping overvoltage protector, leveraging an avalanche breakdown mechanism to divert transient energy away from sensitive downstream circuitry. Its unidirectional configuration ensures forward conduction only during reverse-biased surges, with no conduction in normal forward bias.

Designed for 10/1000 μs waveform compliance, it delivers 600 W peak pulse power dissipation with ≤0.01% duty cycle, supported by low incremental surge resistance and fast response time (<1 ns). Thermal performance is characterized by R_θJA = 100 °C/W and R_θJL = 20 °C/W, requiring minimum 5.0 mm × 5.0 mm copper pads per terminal for rated derating.

Key Specifications

Pinout & Package

Package: SMB (DO-214AA), molded plastic case with matte tin-plated leads, UL 94 V-0 rated, MSL level 1 (260 °C reflow peak), cathode indicated by band marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with P6SMB440AHM3_C/I, SMAJ440A-E3/5B trades peak power for compactness, while 1.5SMC440AHE3_A/H improves thermal robustness at the cost of board area - making P6SMB440AHM3_C/I the optimal balance of surge capacity, AEC-Q101 compliance, and SMB-standard manufacturability.

Availability

P6SMB440AHM3_C/I is available at Aetrix Electronics and suitable for industrial motor drives, telecom power supplies, automotive body control units, and PLC I/O modules requiring stable component supply with halogen-free, AEC-Q101-qualified surge protection.

Supply support for P6SMB440AHM3_C/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 designs and manufactures discrete semiconductors including diodes, MOSFETs, and optoelectronics, with emphasis on high-reliability, industry-qualified components for automotive and industrial markets.

The P6SMB series targets high-energy transient suppression in space-constrained surface-mount applications, combining AEC-Q101 qualification, 600 W pulse capability, and standardized SMB packaging for automated assembly.

FAQ

What is the clamping voltage of the P6SMB440AHM3_C/I under peak pulse conditions?

The P6SMB440AHM3_C/I clamps to a maximum of 602 V when subjected to a 1 A peak pulse current with a 10/1000 μs waveform. This value is measured per standard test conditions in the Vishay datasheet (Document Number: 88370, Rev. 09-Jan-2024) and defines the upper voltage limit imposed on protected circuitry during surge events. The P6SMB440AHM3_C/I maintains this clamping performance across its specified operating temperature range.

Is the P6SMB440AHM3_C/I AEC-Q101 qualified, and what does the 'HM3' suffix indicate?

Yes, the P6SMB440AHM3_C/I is AEC-Q101 qualified - confirmed by the 'HM3' suffix, which denotes halogen-free, RoHS-compliant construction with full automotive stress testing. The 'D' variant suffix (e.g., HM3_D) applies to P6SMB250A–P6SMB540A devices like the P6SMB440AHM3_C/I, verifying qualification per AEC-Q101 Rev D. This makes the P6SMB440AHM3_C/I suitable for under-hood and chassis-mounted automotive electronics.

What is the standoff voltage (V_WM) of the P6SMB440AHM3_C/I, and how does it relate to system operating voltage?

The P6SMB440AHM3_C/I has a standoff voltage (V_WM) of 376 V, meaning it remains non-conductive up to this reverse DC voltage during normal operation. It is intended for use on systems with nominal DC bus voltages ≤376 V - such as 300 VDC industrial supplies or 400 VDC telecom rectifiers with sufficient derating margin. Exceeding V_WM risks premature leakage or thermal runaway, so the P6SMB440AHM3_C/I must be applied with appropriate voltage margin per design guidelines.

Does the P6SMB440AHM3_C/I have bidirectional capability, and how is polarity identified?

No, the P6SMB440AHM3_C/I is a unidirectional TVS diode, as indicated by the absence of a 'C' suffix (e.g., P6SMB440CA). Polarity is marked by a cathode band on the SMB package body; the banded end is the cathode and must be connected to the higher-potential side of the protected line. Bidirectional variants require explicit 'CA' designation and exhibit symmetric clamping in both directions - a feature not present in the P6SMB440AHM3_C/I.

What PCB pad layout is required to achieve the rated 600 W pulse power for the P6SMB440AHM3_C/I?

To achieve the full 600 W peak pulse power rating, the P6SMB440AHM3_C/I must be mounted on minimum 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal, as specified in Figure 2 of the Vishay datasheet. Smaller pads cause thermal derating - e.g., at 75 °C ambient, power capability drops to ~400 W with standard 2.5 mm × 2.5 mm pads. The P6SMB440AHM3_C/I's thermal resistance (R_θJA = 100 °C/W) is directly dependent on this layout.