Taiwan Semiconductor Corporation P6SMB20

Overview

P6SMB20 from Taiwan Semiconductor is a unidirectional 600W surface-mount transient voltage suppressor (TVS) diode with a breakdown voltage range of 18.0–22.0 V, stand-off voltage of 16.2 V, and clamping voltage of 29.1 V at 21 A peak pulse current. It features glass-passivated junction, <1 μA reverse leakage at 16.2 V, and sub-1 ps response time, designed for overvoltage protection in DC power rails of switching mode power supplies and consumer displays.

For engineers reviewing the P6SMB20 datasheet, P6SMB20 pinout, P6SMB20 application, or P6SMB20 equivalent, this page delivers verified electrical specs, DO-214AA package details, clamping performance under 10/1000 μs transients, thermal resistance data (R_θJA = 55 °C/W), and direct alternatives for industrial power rail surge protection.

Technical Context

The P6SMB20 operates as a unidirectional avalanche diode, triggering when reverse voltage exceeds its minimum breakdown voltage (18.0 V) at 1.0 mA test current. Its clamping action limits transient-induced voltage to ≤29.1 V at 21 A (10/1000 μs waveform), enabling robust protection of downstream ICs rated for ≤30 V operation.

Thermally, it sustains 600 W non-repetitive peak pulse power with junction temperature limited to 150 °C, and exhibits R_θJC = 10 °C/W and R_θJA = 55 °C/W - critical for PCB layout decisions in high-density power converters where ambient temperature exceeds 70 °C.

Key Specifications

Pinout & Package

Package: DO-214AA (SMB), surface-mount, molded plastic case with matte tin-plated leads; polarity indicated by cathode band; weight ≈ 0.090 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with P6SMB20, SMBJ20A offers tighter breakdown tolerance and higher surge current headroom at slightly elevated clamping, while 1.5SMC20A trades miniaturization for superior thermal performance - making P6SMB20 optimal for compact, cost-sensitive 24 V DC protection where layout area and leakage are critical.

Availability

P6SMB20 is available at Aetrix Electronics and suitable for switching mode power supplies, monitor DC input protection, and industrial adapter output stages requiring stable component supply, full traceability, and long-term lifecycle support.

Supply support for P6SMB20 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

Taiwan Semiconductor Corporation (TSC) is a vertically integrated semiconductor manufacturer specializing in discrete power devices, TVS diodes, rectifiers, and MOSFETs for industrial, computing, and consumer markets.

The P6SMB series belongs to TSC's surface-mount TVS portfolio engineered for high-energy transient suppression in compact power systems - emphasizing low leakage, fast response, and automotive-grade reliability (ISO 7637-2).

FAQ

What is the maximum clamping voltage of P6SMB20 under standard surge conditions?

The P6SMB20 has a maximum clamping voltage (V_C) of 29.1 V when subjected to a 10/1000 μs waveform peak pulse current of 21 A. This value is measured per ANSI/IEEE C62.35 and represents the upper limit of voltage seen by downstream circuitry during a standardized surge event - critical for ensuring compatibility with 30 V-rated components in the protected path.

Is P6SMB20 unidirectional or bidirectional, and how is polarity marked?

P6SMB20 is a unidirectional TVS diode, with polarity indicated by a cathode band on the DO-214AA package body. The cathode terminal connects to the protected line (e.g., +24 V rail), while the anode connects to ground. Bidirectional variants require "C" or "CA" suffixes (e.g., P6SMB20C), which are not applicable to the P6SMB20 part number.

What is the standoff voltage (V_WM) of P6SMB20, and why does it matter for circuit design?

The standoff voltage (V_WM) of P6SMB20 is 16.2 V - the maximum continuous reverse voltage it can block without significant leakage. This parameter ensures the device remains non-conductive during normal operation of a 24 V DC system, preserving efficiency and avoiding false triggering. Designers must verify that V_WM exceeds the system's maximum steady-state voltage by ≥10% to prevent thermal runaway.

Does P6SMB20 meet automotive transient standards, and which ones specifically?

Yes, P6SMB20 meets ISO 7637-2 for automotive electromagnetic compatibility, covering Pulse 1 (inductive load disconnect), Pulse 2a/2b (switching transients), and Pulse 3a/3b (capacitive coupling). This validation confirms its suitability for 12 V/24 V vehicle subsystems such as infotainment power supplies and body control modules - provided layout adheres to grounding and trace-length guidelines in the standard.

What is the thermal resistance (R_θJA) of P6SMB20, and how does it affect PCB layout?

P6SMB20 has a junction-to-ambient thermal resistance (R_θJA) of 55 °C/W under standard JEDEC test conditions (single-layer 1 in² copper pad). This value means each watt of dissipated surge energy raises the junction temperature by 55 °C above ambient. To maintain T_J ≤150 °C in a 70 °C environment, designers should limit average surge duty cycle and consider adding thermal relief pads or ground-plane connections to reduce effective R_θJA.