Microchip Technology 1PMT5942/TR13

Overview

1PMT5942B from Microsemi is a 51 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 70 Ω dynamic impedance at 7.3 mA test current and 1100 µA max reverse leakage at 38.8 V. It serves as a precision voltage reference or overvoltage clamp in power supply regulation circuits.

For engineers reviewing the 1PMT5942B datasheet, 1PMT5942B pinout, 1PMT5942B application, or 1PMT5942B equivalent, key selection criteria include its 51 V nominal Zener voltage, 3.0 W thermal capability with metallic-tab heatsinking, DO-216 mechanical outline, and ESD rating >16 kV HBM - all critical for compact, high-reliability DC rail protection.

Technical Context

This device operates as a two-terminal voltage-regulating diode with cathode designated by TAB 1. Its Zener voltage is specified at 51 V ±5% under 7.3 mA test current (IZT), with knee current IZK = 0.25 mA and corresponding knee impedance ZZK = 1100 Ω.

Thermal performance is defined by junction-to-TAB1 thermal resistance of 30°C/W and operating junction temperature range of –55°C to +150°C. The full metallic bottom and locking tab enable efficient heat transfer and flux-free reflow assembly.

Key Specifications

Pinout & Package

Package: Powermite® (DO-216AA) surface-mount molded case with full metallic bottom and integral heat-sink locking tab; cathode identified by TAB 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMCJ51A and BZX84-C51, the 1PMT5942B uniquely combines 3.0 W continuous Zener regulation, DO-216 mechanical robustness, and metallic-tab thermal management - making it irreplaceable in high-power, thermally demanding reference or clamp roles.

Availability

1PMT5942B is available at Aetrix Electronics and suitable for DC power supply regulation, overvoltage protection clamp, and industrial sensor excitation requiring stable component supply and long-term manufacturability.

Supply support for 1PMT5942B 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 U.S.-based semiconductor company specializing in high-reliability analog, mixed-signal, and radiation-hardened components.

The Powermite® Zener series was designed for high-power surface-mount voltage regulation in space-constrained, thermally demanding industrial and telecom power systems.

FAQ

What is the Zener voltage tolerance for 1PMT5942B?

The 1PMT5942B has a standard Zener voltage tolerance of ±5% at 51 V, measured at 7.3 mA test current and TAB 1 temperature of 30°C. Tighter tolerances of ±2% (suffix C) and ±1% (suffix D) are available upon request. This tolerance directly impacts regulation accuracy in feedback loops and reference circuits using the 1PMT5942B.

How is thermal management implemented in the 1PMT5942B package?

The 1PMT5942B uses the Powermite® package with a full metallic bottom and integral locking tab that serves as both cathode connection and primary heat sink. Its junction-to-TAB1 thermal resistance is 30°C/W, enabling 3.0 W power dissipation when TAB 1 is maintained at 60°C. Proper PCB copper pour under TAB 1 is essential to achieve rated performance for the 1PMT5942B.

Is the 1PMT5942B compatible with automated assembly processes?

Yes, the 1PMT5942B is fully compatible with automated insertion and surface-mount assembly. It is supplied in EIA-481-compliant tape-and-reel format (3,000 pieces per 7-inch reel), and its Powermite® package geometry supports reliable pick-and-place handling. The full metallic bottom also prevents solder flux entrapment during reflow, enhancing process yield for the 1PMT5942B.

What is the maximum reverse leakage current for 1PMT5942B?

The 1PMT5942B specifies a maximum reverse leakage current (IR) of 1100 µA at a reverse voltage (VR) of 38.8 V, measured at TL = 30°C. This value reflects the device's ability to maintain low off-state current prior to Zener conduction, critical for minimizing quiescent power loss in high-impedance reference networks using the 1PMT5942B.

Does the 1PMT5942B have ESD protection, and what is its rating?

Yes, the 1PMT5942B has an ESD rating exceeding 16 kV per the Human Body Model (HBM), as confirmed in the official Microsemi datasheet. This high ESD immunity supports robust handling during manufacturing, testing, and field operation - a key reliability feature distinguishing the 1PMT5942B from generic Zener diodes.