Microchip Technology 1PMT5948/TR7

Overview

1PMT5948B from Microsemi is a 91 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 200 Ω dynamic impedance at 4.1 mA test current and 3000 µA max reverse leakage at 69.2 V. It serves as a precision voltage reference or overvoltage clamp in DC power rails of industrial motor drives and telecom power supplies.

For engineers reviewing the 1PMT5948B datasheet, 1PMT5948B pinout, 1PMT5948B application, or 1PMT5948B equivalent, key selection criteria include its 91 V nominal zener voltage, 3.0 W thermal capability via metallic tab, DO-216 mechanical outline, ESD rating >16 kV HBM, and compatibility with automated SMT insertion equipment.

Technical Context

This Zener diode operates in reverse breakdown mode with tightly controlled voltage regulation across its specified test current range. Its Powermite® package integrates a full metallic bottom and locking tab to ensure low thermal resistance (30°C/W junction-to-TAB1) and reliable heat transfer during sustained 3.0 W dissipation.

The device exhibits low reverse leakage (≤3000 µA at VR = 69.2 V), stable knee behavior (IZK = 0.25 mA), and defined dynamic impedance (ZZT = 200 Ω at IZT = 4.1 mA), enabling predictable clamping performance in transient suppression and reference circuits.

Key Specifications

Pinout & Package

Package: Powermite® (DO-216), molded surface-mount package with full metallic bottom and integral locking tab acting as thermal path and mechanical anchor. 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 SMCJ91A and BZX84-C91, the 1PMT5948B uniquely combines 3.0 W continuous power handling, metallic thermal tab, and ±5% zener tolerance in a surface-mount package-making it suitable for regulated clamping where both precision and thermal robustness are required.

Availability

1PMT5948B is available at Aetrix Electronics and suitable for industrial motor drives, telecom power systems, automated test equipment, and renewable energy inverters requiring stable component supply and long-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 for aerospace, defense, and industrial markets.

The Powermite® Zener series-including 1PMT5948B-is engineered for high-power surface-mount voltage regulation and transient suppression in harsh-environment power systems where thermal performance and mechanical robustness are critical.

FAQ

What is the maximum continuous power dissipation for 1PMT5948B?

The 1PMT5948B is rated for 3.0 W DC power dissipation when TAB 1 is maintained at 60°C. This rating assumes proper thermal coupling of the metallic tab to a PCB copper area or external heatsink. Derating is required above 60°C tab temperature per the device's thermal resistance of 30°C/W.

Does 1PMT5948B have a defined polarity marking, and how is it identified?

Yes, 1PMT5948B uses TAB 1 as the cathode terminal, clearly designated in the mechanical drawing and datasheet. The cathode is marked by the larger metallic tab; lead 2 is the anode. This polarity must be observed during PCB layout and assembly to ensure correct reverse-bias operation.

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

The reverse leakage current for 1PMT5948B is specified as ≤3000 µA maximum at VR = 69.2 V, measured at TL = 30°C. This value reflects worst-case leakage under conditions approaching but below the zener breakdown threshold, ensuring low standby power in always-connected protection circuits.

Can 1PMT5948B be used in automated SMT assembly processes?

Yes, 1PMT5948B is explicitly designed for compatibility with automatic insertion and SMT reflow processes. Its Powermite® package features a unique locking tab and full metallic bottom that prevent flux entrapment and improve placement accuracy-validated per EIA-481 tape-and-reel packaging standards.

Is there a tighter tolerance version of 1PMT5948B available, and how is it ordered?

Yes, 1PMT5948B is available in ±2% and ±1% zener voltage tolerance variants, designated by adding suffix "C" (e.g., 1PMT5948BC) and "D" (e.g., 1PMT5948BD), respectively. These versions retain identical electrical and thermal specifications except for the tightened VZ tolerance band.