Microchip Technology 1PMT5948/TR13

Overview

1PMT5948B from Microsemi is a 3.0 W surface-mount Zener diode in Powermite® package with nominal zener voltage 91 V (±5%), dynamic impedance 200 Ω at 4.1 mA test current, and thermal resistance 30°C/W junction-to-tab. It serves as precision voltage reference or overvoltage clamp in DC power rails of industrial control modules.

For engineers reviewing the 1PMT5948B datasheet, 1PMT5948B pinout, 1PMT5948B application, or 1PMT5948B equivalent, key selection criteria include zener voltage tolerance, power derating above 60°C tab temperature, reverse leakage ≤1 µA at 69.2 V, and compatibility with EIA-481 tape-and-reel automation.

Technical Context

This Zener diode operates in reverse breakdown mode with tightly controlled knee characteristics: knee current IZK = 0.25 mA and knee impedance ZZK = 3000 Ω, enabling stable regulation even at low bias currents. Its full metallic bottom and integral heat sink tab (TAB 1) ensure reliable thermal transfer to PCB copper during continuous 3.0 W dissipation.

The device meets >16 kV HBM ESD rating and supports automatic insertion equipment due to its molded DO-216 outline and locking tab geometry. Junction temperature range is –55°C to +150°C, with storage and operating limits aligned to industrial-grade reliability requirements.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5948B and BZX85C91, the 1PMT5948B delivers superior thermal performance (30°C/W vs. ≥50°C/W), integrated mechanical anchoring for SMT reliability, and certified >16 kV HBM ESD protection-critical for high-volume automated production.

Availability

1PMT5948B is available at Aetrix Electronics and suitable for industrial power supplies, automated test equipment, motor drive protection, and telecom line interface designs requiring stable component supply with full traceability and lifecycle support.

Supply support for 1PMT5948B 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 diode product line targets compact, thermally efficient voltage regulation and transient suppression in space-constrained industrial and telecom systems.

FAQ

What is the maximum power dissipation of the 1PMT5948B and under what conditions?

The 1PMT5948B has a maximum DC power dissipation of 3.0 W when the tab temperature (TL) is maintained at 60°C. Derating is required above this temperature at 40 mW/°C, per the thermal resistance of 30°C/W. This rating assumes proper PCB copper thermal relief and direct tab-to-copper contact. The 1PMT5948B must not exceed its absolute maximum junction temperature of +150°C during operation.

How is cathode identification implemented on the 1PMT5948B package?

The cathode of the 1PMT5948B is unambiguously designated by TAB 1-the large metallic tab on the package bottom. This tab serves both as the cathode electrical terminal and the primary thermal path. Lead 2 (the top-side lead opposite the tab) is the anode. No polarity marking appears on the molded body; correct orientation relies solely on tab placement during placement and soldering.

Does the 1PMT5948B support automated SMT assembly, and what packaging format is used?

Yes, the 1PMT5948B is fully compatible with automated insertion equipment due to its DO-216 outline, locking tab geometry, and EIA-481 compliant tape-and-reel packaging. It ships in 7-inch reels containing 3,000 units or 13-inch reels with 12,000 units. The full metallic bottom prevents flux entrapment during reflow, enhancing first-pass yield in high-speed SMT lines.

What is the reverse leakage current specification for the 1PMT5948B, and at what voltage is it measured?

The 1PMT5948B specifies a maximum reverse leakage current (IR) of 1 µA at a reverse voltage (VR) of 69.2 V-75% of its nominal 91 V zener voltage. This low leakage ensures minimal quiescent current draw in high-impedance bias networks and reference dividers, supporting energy-efficient designs where standby power is critical.

Is the 1PMT5948B rated for ESD sensitivity, and what level does it withstand?

Yes, the 1PMT5948B is rated for >16 kV electrostatic discharge per the Human Body Model (HBM), as confirmed in the official Microsemi datasheet MSC0995. This high ESD immunity eliminates the need for additional handling precautions during automated assembly and improves field reliability in environments prone to static discharge, such as factory-floor test stations.