Microchip Technology 1PMT5940/TR13

Overview

1PMT5940B from Microsemi is a 43 V, 3.0 W surface-mount Zener diode in the Powermite® package (DO-216), featuring 8.7 mA test current, 53 Ω dynamic impedance at IZT, 1 µA max reverse leakage at 32.7 V, and thermal resistance of 30°C/W junction-to-tab. It serves as a precision voltage reference or overvoltage clamp in power supply regulation and transient protection circuits.

For engineers reviewing the 1PMT5940B datasheet, 1PMT5940B pinout, 1PMT5940B application, or 1PMT5940B equivalent, key selection criteria include zener voltage tolerance (±5% standard), low knee impedance (0.25 Ω), ESD rating (>16 kV HBM), full metallic bottom for flux-free soldering, and compatibility with automated insertion equipment.

Technical Context

This Zener diode operates with a nominal zener voltage of 43 V at 8.7 mA test current (IZT), delivering stable regulation under DC bias with tight voltage control across temperature (–55°C to +150°C junction range). Its 30°C/W thermal resistance from junction to tab (TAB 1) enables effective heat dissipation in high-density layouts.

The device exhibits low reverse leakage (≤1 µA at VR = 32.7 V), 53 Ω dynamic impedance at IZT, and a sharp knee characteristic (IZK = 0.25 mA, ZZK = 950 Ω), supporting accurate clamping in low-current sensing and reference applications.

Key Specifications

Pinout & Package

Package: Powermite® (DO-216), 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 1N5357B and SZ1SMA5940E, the 1PMT5940B uniquely combines 3.0 W capability with DO-216's compact footprint, metallic thermal tab, and flux-free bottom-making it optimal for high-reliability, automated SMT power regulation where board space and thermal management are co-constrained.

Availability

1PMT5940B is available at Aetrix Electronics and suitable for switch-mode power supplies, industrial sensor interfaces, automotive body control modules, and programmable logic controller input protection requiring stable component supply and long-lifecycle support.

Supply support for 1PMT5940B 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 for aerospace, defense, and industrial markets.

The Powermite® Zener diode product line was engineered for high-power density surface-mount voltage regulation in space-constrained, thermally demanding applications-emphasizing manufacturability, thermal efficiency, and ESD resilience.

FAQ

What is the zener voltage tolerance for 1PMT5940B?

The standard 1PMT5940B has a zener voltage tolerance of ±5% at 43 V. Tighter tolerances of ±2% (suffix C) and ±1% (suffix D) are available upon request. Voltage is measured at 8.7 mA test current with TAB 1 held at 30°C, and readings must be taken within 20 seconds of applying DC current to avoid self-heating effects. This tolerance directly impacts regulation accuracy in precision reference circuits.

How is thermal management handled in the 1PMT5940B package?

The 1PMT5940B uses its metallic TAB 1 as the primary thermal conduction path, with a specified junction-to-tab thermal resistance of 30°C/W. To achieve rated 3.0 W power dissipation, TAB 1 must be soldered to a sufficiently sized copper thermal pad on the PCB. The full metallic bottom eliminates flux entrapment, ensuring consistent solder joint quality and long-term thermal interface reliability-critical for sustained operation in industrial and automotive environments.

Can 1PMT5940B be used in automated SMT assembly?

Yes, the 1PMT5940B is explicitly designed for compatibility with automatic insertion and surface-mount equipment. Its Powermite® package features standardized dimensions per DO-216, a locking tab that aids orientation and retention during placement, and a flat, flux-free metallic bottom that prevents solder defects. Tape-and-reel packaging follows EIA-481 standards (7″ reel: 3,000 pcs; 13″ reel: 12,000 pcs), enabling seamless integration into high-volume manufacturing lines.

What is the maximum reverse leakage current for 1PMT5940B?

The maximum reverse leakage current for 1PMT5940B is 1 µA at a reverse voltage of 32.7 V (75% of nominal VZ), measured at TL = 30°C. This low leakage preserves signal integrity in high-impedance bias networks and sensor conditioning circuits. Leakage remains well-controlled up to the full junction temperature range (–55°C to +150°C), making the 1PMT5940B suitable for battery-powered and precision analog applications where standby current matters.

Does 1PMT5940B meet industry ESD standards?

Yes, the 1PMT5940B is rated for >16 kV per the Human Body Model (HBM), exceeding JEDEC JS-001 Class 3A requirements. This high ESD immunity is built into the die and package design, eliminating the need for external protection in many applications. The robustness supports safe handling during assembly and enhances system-level resilience against electrostatic discharge in industrial control and automotive electronics-key for designs targeting IEC 61000-4-2 compliance.