onsemi P6SMB180AT3

Overview

P6SMB180AT3 from ON Semiconductor is a unidirectional 600 W transient voltage suppressor (TVS) diode designed for overvoltage protection of sensitive electronics in DC power lines and signal paths. It features a 154 V working peak reverse voltage (VRWM), 180 V breakdown voltage (VBR) at 1 mA test current, clamps to ≤246 V at 180 A peak pulse current (IPP), and responds in <1 ns. It is used in industrial power supplies to protect rectifier outputs and DC bus rails against lightning-induced surges.

For engineers reviewing the P6SMB180AT3 datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM margin above operating voltage, clamping voltage vs. protected device withstand rating, peak pulse current capability under IEC 61000-4-5 waveform, and UL 497B recognition for isolated loop circuit protection.

Technical Context

The P6SMB180AT3 operates as a unidirectional Zener-based TVS, conducting only during negative transients relative to its anode–cathode polarity. Its junction structure enables low dynamic impedance (<0.5 Ω typical) during clamping and maintains leakage <5 µA at VRWM = 154 V.

It complies with UL 497B for isolated loop circuit protection and meets Class 3 ESD immunity (>16 kV HBM). Thermal design requires attention to junction-to-lead resistance (RJL = 40 °C/W) and derating above 75°C - critical for sustained surge duty in enclosed power modules.

Key Specifications

Pinout & Package

Package: SMB (Case 403A), surface-mount, Pb-free, void-free thermosetting plastic with modified L-bend leads and cathode polarity band.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ180A and 1.5SMC180A, the P6SMB180AT3 uniquely combines UL 497B certification, SMB footprint compatibility, and precise 154 V VRWM - making it the preferred choice for certified, compact, and cost-sensitive DC bus protection in medical and telecom systems.

Availability

P6SMB180AT3 is available at Aetrix Electronics and suitable for industrial power supplies, DC motor drives, telecom remote power feeds, and medical isolated DC links requiring stable component supply and full regulatory documentation traceability.

Supply support for P6SMB180AT3 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

ON Semiconductor is a global semiconductor supplier specializing in energy-efficient power management, analog, sensor, and connectivity solutions for automotive, industrial, and communications markets.

The P6SMB180AT3 belongs to the P6SMBxxAT3 series of unidirectional TVS diodes engineered for robust, standards-compliant overvoltage protection in high-reliability DC power and signal interfaces.

FAQ

What is the clamping voltage of the P6SMB180AT3 at its rated peak pulse current?

The P6SMB180AT3 clamps to a maximum of 246 V at its rated peak pulse current of 180 A (10/1000 µs waveform). This value is measured under standardized test conditions and defines the upper voltage limit imposed on protected circuitry during surge events. The P6SMB180AT3 achieves this clamping performance while maintaining low dynamic impedance and sub-microamp leakage below VRWM.

Does the P6SMB180AT3 meet UL 497B requirements for isolated loop protection?

Yes, the P6SMB180AT3 carries UL 497B recognition (File #E210057, Category QVGQ2) for isolated loop circuit protection. This certification confirms successful completion of strike voltage breakdown, endurance conditioning, dielectric withstand, and discharge tests - distinguishing it from generic TVS diodes lacking formal protector-category approval. The P6SMB180AT3 is validated for use in telecom power feeds and other isolated applications requiring third-party safety validation.

What is the working peak reverse voltage (VRWM) specification for the P6SMB180AT3?

The P6SMB180AT3 has a working peak reverse voltage (VRWM) of 154 V, meaning it remains in high-impedance blocking mode with leakage <5 µA up to this DC or continuous peak voltage. This parameter determines the maximum steady-state voltage the P6SMB180AT3 can withstand without significant conduction - critical for selecting appropriate overvoltage margin in 24 V, 48 V, or 110 V DC systems. The P6SMB180AT3's 154 V VRWM provides 2× margin over nominal 72 V DC bus applications.

Is the P6SMB180AT3 RoHS-compliant and compatible with standard SMT reflow processes?

Yes, the P6SMB180AT3 is Pb-free and RoHS-compliant, packaged in ON Semiconductor's SURMETIC® SMB case (Case 403A). It supports standard lead-free reflow profiles with a maximum soldering temperature of 260°C for 10 seconds. The modified L-bend leads ensure reliable solder joint formation on FR-4 PCBs, and the void-free thermosetting plastic body maintains mechanical integrity during thermal cycling. The P6SMB180AT3 is qualified for high-volume automated assembly without special process adjustments.

How does the response time of the P6SMB180AT3 impact its effectiveness in protecting fast-switching circuits?

The P6SMB180AT3 has a typical response time of <1 ns, enabling it to initiate clamping before most fast-switching transients (e.g., MOSFET turn-off spikes or ESD events) propagate through PCB traces. This speed minimizes voltage overshoot at the protected node - especially critical for circuits containing GaN FETs or high-speed ADCs with tight absolute maximum ratings. Because the P6SMB180AT3 reacts faster than board-level parasitic inductance can develop significant overshoot, its placement within 5 mm of the protected IC is sufficient to achieve full benefit without complex layout constraints.