onsemi P6SMB36CAT3

Overview

P6SMB36CAT3 from ON Semiconductor is a bidirectional 600 W transient voltage suppressor (TVS) diode designed for parallel overvoltage protection in DC power rails and signal lines. It features a 30.8 V working peak reverse voltage (VRWM), 36 V nominal Zener breakdown voltage (VBR), clamps to ≤49.9 V at 12 A peak pulse current (IPP), and responds in <1 ns - used in automotive power supplies, industrial I/O interfaces, and medical equipment surge protection.

For engineers reviewing the P6SMB36CAT3 datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM margin vs. operating voltage, clamping voltage under specified IPP, thermal derating above 75°C, UL 497B certification for isolated loop protection, and SMB package compatibility with IPC-7351B footprint standards.

Technical Context

The P6SMB36CAT3 operates as a bidirectional avalanche diode, symmetrically clamping both positive and negative transients across its terminals. Its low zener impedance (<1 Ω typical) and fast response (<1 ns) enable effective suppression of ESD (Class 3, >16 kV HBM) and lightning-induced surges per IEC 61000-4-5.

Thermal design relies on junction-to-lead resistance (RJL = 40 °C/W) and derating above 75°C (25 mW/°C), with maximum case temperature rated at 260°C for 10 s during soldering. The device is not intended for continuous forward conduction and must be applied with series impedance to limit peak current during clamping.

Key Specifications

Pinout & Package

Package: SMB (DO-214AA, Case 403A), surface-mount, void-free thermosetting plastic with modified L-bend leads. Dimensions: 4.32 mm × 3.56 mm × 2.13 mm (L × W × H), 2.03 mm lead width, 1.02 mm lead length.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ36CA and 1.5SMC36CA, the P6SMB36CAT3 delivers optimal balance of compact SMB footprint, industry-leading 49.9 V clamping at 12 A, UL 497B recognition, and proven Surmetic® reliability - making it preferred for cost-sensitive, space-limited industrial and automotive modules.

Availability

P6SMB36CAT3 is available at Aetrix Electronics and suitable for automotive electronics, industrial programmable logic controllers, and medical diagnostic equipment requiring stable component supply and long-term lifecycle support.

Supply support for P6SMB36CAT3 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 (now onsemi) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The P6SMB36CAT3 belongs to the P6SMBxxCAT3 series - a family of 600 W bidirectional TVS diodes engineered for robust, certified overvoltage protection in harsh environments where UL 497B compliance and low clamping voltage are critical.

FAQ

What is the clamping voltage of the P6SMB36CAT3 and how is it measured?

The P6SMB36CAT3 has a maximum clamping voltage (VC) of 49.9 V at 12 A peak pulse current (IPP), tested using the standardized 10/1000 µs double-exponential surge waveform. This value is guaranteed per datasheet Note 6 and reflects the highest voltage the device allows across its terminals during a full-rated 600 W transient event - critical for ensuring downstream ICs remain within their absolute maximum ratings. The P6SMB36CAT3 achieves this with low dynamic impedance and symmetric bidirectional structure.

Is the P6SMB36CAT3 RoHS compliant and what does the 'G' suffix indicate?

Yes, the P6SMB36CAT3 is RoHS compliant. The 'G' suffix in P6SMB36CAT3G explicitly denotes the Pb-free version, meeting JEDEC J-STD-020 moisture sensitivity level 1 and qualified for lead-free reflow up to 260°C for 10 seconds. ON Semiconductor confirms this construction in the ordering information table and mechanical specifications - the P6SMB36CAT3 and P6SMB36CAT3G share identical electrical performance and thermal characteristics, differing only in plating composition.

Does the P6SMB36CAT3 require polarity-aware PCB layout?

No, the P6SMB36CAT3 does not require polarity-aware PCB layout. As a bidirectional TVS diode, it functions identically regardless of orientation - both terminals serve as cathode during opposite-polarity transients. The datasheet explicitly states "Polarity Band Will Not be Indicated", and the marking diagram shows no polarity identifier. This simplifies assembly and eliminates risk of reverse installation in high-volume manufacturing of the P6SMB36CAT3.

How does the P6SMB36CAT3 compare to unidirectional TVS diodes like P6SMB36AT3?

The P6SMB36CAT3 is bidirectional, while P6SMB36AT3 is unidirectional - meaning the latter only clamps positive transients and blocks negative voltage beyond its reverse standoff. For AC-coupled or floating signal lines (e.g., RS-485, CAN bus), the P6SMB36CAT3 provides symmetrical protection without external biasing. In contrast, P6SMB36AT3 requires careful DC biasing to avoid unintended conduction; the P6SMB36CAT3 eliminates that design constraint entirely.

What is the thermal derating behavior of the P6SMB36CAT3 above 75°C?

The P6SMB36CAT3 derates linearly above 75°C at 25 mW/°C for DC power dissipation (PD), based on its thermal resistance junction-to-lead (RJL = 40 °C/W). While peak pulse power remains 600 W for single events, sustained repetitive surges require ambient or lead temperature monitoring. The datasheet Figure 3 shows 40% derating at 125°C ambient - meaning average surge energy must be reduced accordingly. This behavior is intrinsic to the P6SMB36CAT3's Surmetic® package construction and must be modeled in thermal simulations for high-temperature deployments.