Microchip Technology 1PMT5942B/TR7

Overview

1PMT5942B/TR7 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 DC power rails and regulator feedback networks.

For engineers reviewing the 1PMT5942B/TR7 datasheet, 1PMT5942B/TR7 pinout, 1PMT5942B/TR7 application, or 1PMT5942B/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 (400 Ω at 0.25 mA), and compatibility with automated SMT assembly per EIA-481 tape-and-reel packaging.

Technical Context

This device operates as a two-terminal voltage-regulating diode with sharp reverse-breakdown characteristics. Its Powermite® package integrates a full metallic bottom and locking tab to enhance thermal conduction and mechanical stability during reflow soldering.

The 1PMT5942B/TR7 exhibits 70 Ω dynamic impedance at I_ZT = 7.3 mA and maintains ≤1100 µA reverse leakage at V_R = 38.8 V, supporting stable regulation under varying load and temperature conditions across -55°C to +150°C junction range.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C51LT1G and SMBJ51A, the 1PMT5942B/TR7 uniquely combines 3.0 W DC power handling, 70 Ω dynamic impedance, and thermal design support via TAB 1-making it suitable for sustained voltage regulation where alternatives either lack power capability or regulate poorly under DC bias.

Availability

1PMT5942B/TR7 is available at Aetrix Electronics and suitable for DC power rail clamping, voltage reference for feedback loops, ESD protection for sensor inputs, and overvoltage detection in battery management requiring stable component supply and traceable sourcing.

Supply support for 1PMT5942B/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 U.S.-based semiconductor company specializing in high-reliability analog, mixed-signal, and RF solutions for aerospace, defense, and industrial markets.

The Powermite® Zener diode family-including 1PMT5942B/TR7-is engineered for high-power surface-mount voltage regulation in space-constrained, thermally demanding applications where traditional through-hole or low-power SMT devices fall short.

FAQ

What is the zener voltage tolerance for 1PMT5942B/TR7?

The 1PMT5942B/TR7 has a standard zener voltage tolerance of ±5% at 51 V, measured at 7.3 mA test current with TAB 1 held at 30°C. Tighter tolerances of ±2% (suffix C) and ±1% (suffix D) are available upon request. This tolerance directly impacts regulation accuracy in feedback and reference applications.

How is thermal performance managed in the 1PMT5942B/TR7 package?

The 1PMT5942B/TR7 uses the Powermite® package with TAB 1 as the cathode and primary thermal path. Its junction-to-TAB thermal resistance is 30°C/W, enabling 3.0 W DC power dissipation when TAB 1 is maintained at ≤60°C. PCB layout must provide adequate copper area under TAB 1 to achieve rated performance.

Can 1PMT5942B/TR7 be used in automated SMT assembly?

Yes, the 1PMT5942B/TR7 is supplied in EIA-481 compliant tape-and-reel format (3,000 units per 7-inch reel) and features a locking tab and full metallic bottom designed for compatibility with automatic insertion and reflow processes. Its DO-216AA outline meets standard pick-and-place tooling requirements.

What is the maximum reverse leakage current for 1PMT5942B/TR7?

The 1PMT5942B/TR7 specifies a maximum reverse leakage current of 1100 µA at a reverse voltage of 38.8 V, measured at T_L = 30°C. This low leakage supports stable operation in high-impedance bias networks and minimizes standby power loss in voltage reference circuits.

Does 1PMT5942B/TR7 have ESD protection built-in?

Yes, the 1PMT5942B/TR7 is rated for >16 kV per the Human Body Model (HBM), verified per ANSI/ESDA/JEDEC JS-001. This intrinsic ESD robustness eliminates the need for external protection in many sensor interface and low-energy input applications, reducing BOM count and layout complexity.