Microchip Technology 1PMT5943A/TR7

Overview

1PMT5943A/TR7 from Microsemi is a 56 V, ±5% tolerance surface-mount Zener diode in the Powermite® package, rated for 3.0 W DC power dissipation at TAB 1 = 60°C, with 86 Ω dynamic impedance at 6.7 mA test current and 1300 µA max reverse leakage at 42.6 V. It serves as a precision voltage reference or overvoltage clamp in DC power rails and regulator feedback networks.

For engineers reviewing the 1PMT5943A/TR7 datasheet, 1PMT5943A/TR7 pinout, 1PMT5943A/TR7 application, or 1PMT5943A/TR7 equivalent, key selection criteria include zener voltage accuracy, thermal resistance (30°C/W junction-to-TAB), ESD rating (>16 kV HBM), low knee impedance, and compatibility with automated SMT assembly using EIA-481 tape-and-reel packaging.

Technical Context

This device operates as a two-terminal voltage-regulating diode with a defined breakdown threshold at 56 V nominal. Its Powermite® package integrates a full metallic bottom and locking tab that functions as both mechanical anchor and thermal path to PCB copper, enabling efficient heat transfer from junction to TAB 1.

Electrical behavior is characterized by tight control of dynamic impedance (86 Ω at I_ZT = 6.7 mA) and low reverse leakage (≤1300 µA at V_R = 42.6 V), supporting stable regulation under varying load and temperature conditions within –55°C to +150°C junction range.

Key Specifications

Pinout & Package

The 1PMT5943A/TR7 uses a 2-terminal DO-216 molded surface-mount package with cathode designated by TAB 1. The full metallic bottom and integral locking tab serve as both mechanical retention feature and primary thermal interface to the PCB.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener diode applications.

Compared with SMCJ56A and BZX84-C56, the 1PMT5943A/TR7 uniquely delivers 3.0 W continuous Zener regulation in a thermally optimized surface-mount package-enabling both precision voltage referencing and robust overvoltage clamping in the same design without compromise.

Availability

1PMT5943A/TR7 is available at Aetrix Electronics and suitable for DC power supply regulation, overvoltage protection circuits, and automotive body control modules requiring stable component supply and long-term lifecycle support.

Supply support for 1PMT5943A/TR7 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

Microsemi (now part of Microchip Technology) is a semiconductor company specializing in high-reliability analog, mixed-signal, and RF solutions for aerospace, defense, and industrial markets.

The Powermite® Zener diode product line was engineered to deliver high-power surface-mount voltage regulation with superior thermal performance and assembly robustness-targeting applications where legacy through-hole packages were unsuitable for automated manufacturing.

FAQ

What is the Zener voltage tolerance for 1PMT5943A/TR7?

The 1PMT5943A/TR7 has a nominal Zener voltage of 56 V with a standard tolerance of ±5%, measured at 6.7 mA test current and TAB 1 temperature of 30°C. Tighter tolerances (±2% and ±1%) are available with suffixes C and D respectively, but the /TR7 variant uses the standard ±5% grade.

How is thermal management handled in the 1PMT5943A/TR7 package?

The 1PMT5943A/TR7 uses a Powermite® package with a full metallic bottom and integral locking tab that serves as the primary thermal path. Its specified thermal resistance is 30°C/W from junction to TAB 1, meaning effective heat sinking requires direct soldering of TAB 1 to a substantial copper area on the PCB to maintain 3.0 W operation at ambient.

Is 1PMT5943A/TR7 compatible with standard SMT reflow processes?

Yes, the 1PMT5943A/TR7 is qualified for standard lead-free reflow profiles. Its Powermite® package features a unique locking tab that enhances mechanical retention during reflow, and its full metallic bottom eliminates solder flux entrapment-reducing voiding risk and improving joint reliability in high-volume automated assembly.

What is the maximum reverse leakage current for 1PMT5943A/TR7?

The maximum reverse leakage current for 1PMT5943A/TR7 is 1300 µA at a reverse voltage of 42.6 V and ambient temperature of 30°C. This value is specified in the Microsemi MSC0995 datasheet and reflects worst-case leakage under defined test conditions, critical for low-power standby circuit design.

Does 1PMT5943A/TR7 have ESD protection built-in?

Yes, the 1PMT5943A/TR7 has an ESD rating exceeding 16 kV per the Human Body Model (HBM), as verified in Microsemi's qualification testing. This high-level ESD robustness supports safe handling during board assembly and improves field reliability in electrically noisy environments without requiring external protection components.