Taiwan Semiconductor Corporation P4SMA39A

Overview

P4SMA39A from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for overvoltage protection in DC power lines and signal paths. It features a 33.3 V working stand-off voltage, 37.1–41.0 V breakdown voltage at 1 mA, 53.9 V maximum clamping voltage at 7.7 A (10/1000 µs), and 400 W peak pulse power dissipation - optimized for protecting switching mode power supplies and on-board DC/DC converters against ISO 7637-2 Pulse 1/2a/2b/3a/3b transients.

For engineers reviewing the P4SMA39A datasheet, P4SMA39A pinout, P4SMA39A application, or P4SMA39A equivalent, key selection criteria include its DO-214AC (SMA) package compatibility, unidirectional polarity with cathode band marking, sub-1 ps response time, <1 µA reverse leakage at V_WM, and compliance with J-STD-020 Level 1 moisture sensitivity - critical for high-reliability automotive and industrial PCB assembly.

Technical Context

The P4SMA39A employs a glass-passivated silicon junction to achieve stable avalanche breakdown behavior under transient stress. Its clamping performance is characterized by a tightly controlled V_BR range (37.1–41.0 V) and low temperature coefficient (0.100 %/°C), ensuring predictable protection across operating temperatures from –55 °C to +150 °C.

It operates as a single-die, unidirectional TVS device in the DO-214AC (SMA) package, with a maximum forward voltage of 3.5 V at 25 A surge current and a peak impulse current rating of 7.7 A under the standardized 10/1000 µs waveform - enabling robust suppression of fast-rising ESD and load-dump events without latch-up or thermal runaway.

Key Specifications

Pinout & Package

Package: DO-214AC (SMA), surface-mount, single-ended unidirectional configuration with molded plastic case meeting UL 94V-0 flammability rating and matte tin-plated leads compliant with J-STD-002 solderability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ36A and 1.5SMC39A, the P4SMA39A offers optimal balance of compact DO-214AC (SMA) size, precise 33.3 V stand-off, and 53.9 V clamping - making it ideal for space-constrained, cost-sensitive automotive and consumer power designs where 400 W surge immunity suffices.

Availability

P4SMA39A is available at Aetrix Electronics and suitable for switching mode power supplies, on-board DC/DC converters, and lighting applications requiring stable component supply, consistent parametric performance, and full traceability across production batches.

Supply support for P4SMA39A 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 Company (TSC) is a vertically integrated semiconductor manufacturer specializing in discrete power devices, TVS diodes, rectifiers, and MOSFETs for automotive, industrial, and consumer markets.

The P4SMA series belongs to TSC's surface-mount TVS portfolio engineered specifically for high-reliability transient suppression in harsh electromagnetic environments - emphasizing low leakage, tight V_BR tolerance, and AEC-Q101-aligned process control.

FAQ

What is the polarity configuration of the P4SMA39A?

The P4SMA39A is a unidirectional TVS diode with clearly marked cathode band indicating the clamping terminal. When installed, the cathode connects to the protected line (e.g., +12 V rail), and the anode connects to ground or return path. This configuration ensures avalanche breakdown occurs only during reverse overvoltage events, while allowing normal forward conduction up to 25 A peak surge current.

Does the P4SMA39A meet automotive transient immunity standards?

Yes, the P4SMA39A meets ISO 7637-2 requirements for Pulse 1 (inductive load dump), Pulse 2a/2b (switching transients), and Pulse 3a/3b (capacitive coupling), validated per its 400 W peak pulse rating and 53.9 V clamping voltage at 7.7 A. While not AEC-Q101 certified out-of-box, its construction and test data align with automotive-grade TVS qualification prerequisites when used within specified thermal and mounting conditions.

What is the maximum operating temperature for the P4SMA39A?

The P4SMA39A has a maximum junction temperature (T_J) of +150 °C and operates across –55 °C to +150 °C. Its thermal derating curve (Fig.2 in datasheet) shows linear power reduction above 25 °C ambient, maintaining 400 W capability only at T_A ≤ 25 °C; at 85 °C ambient, rated peak power drops to approximately 260 W - a critical factor in enclosed power adapter or engine bay designs.

How does the P4SMA39A compare to the P4SMA39 (non-A) variant?

The P4SMA39A differs from P4SMA39 in tighter breakdown voltage tolerance: P4SMA39A specifies 37.1–41.0 V (±5.3%) versus P4SMA39's 35.1–42.9 V (±11.1%). Both share identical V_WM (33.3 V), V_C (53.9 V), and 400 W rating, but the 'A' suffix indicates enhanced V_BR consistency - beneficial for designs requiring precise clamping onset, such as those with narrow voltage margins around 3.3 V or 5 V logic rails.

Is the P4SMA39A compatible with lead-free reflow processes?

Yes, the P4SMA39A is fully compatible with lead-free reflow soldering per J-STD-020 Level 1 moisture sensitivity classification - meaning it can be processed using standard IPC/JEDEC profiles (e.g., peak temperature 260 °C, 60 sec max) without pre-baking. Its matte tin-plated leads meet J-STD-002 solderability requirements, ensuring reliable wetting and joint formation in high-volume SMT assembly.