Microchip Technology 1PMT5931/TR7

Overview

1PMT5931B from Microsemi is a 3.0 W surface-mount Zener diode in the Powermite® package, with nominal zener voltage 18 V at 20.8 mA test current, dynamic impedance 12 Ω, and thermal resistance 30°C/W junction-to-tab. It features full metallic bottom to prevent solder flux entrapment and integral locking tab acting as heat sink, used for voltage regulation in power supply feedback loops.

For engineers reviewing the 1PMT5931B datasheet, 1PMT5931B pinout, 1PMT5931B application, or 1PMT5931B equivalent, key selection criteria include zener voltage tolerance (±5% standard), ESD rating (>16 kV HBM), reverse leakage (≤1 µA at 13.7 V), maximum zener current (68.5 mA), and thermal performance under PCB-mounted conditions.

Technical Context

This Zener diode operates as a precision voltage reference and overvoltage clamp in DC power rails. Its DO-216 package places the cathode on TAB 1, and its 30°C/W thermal resistance enables stable regulation up to 150°C junction temperature when mounted on thermally optimized pads.

The device delivers 18 V regulation with 12 Ω dynamic impedance at 20.8 mA, low knee current (0.25 mA), and tight 1 µA max reverse leakage at 13.7 V - enabling accurate low-current biasing and stable feedback in switching regulator error amplifiers.

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 SMF18A and BZX84-C18, the 1PMT5931B uniquely combines 3.0 W DC power handling, 12 Ω dynamic impedance, and tab-based thermal management - making it the only option among the three suitable for continuous-duty voltage regulation in 12–24 V industrial power supplies.

Availability

1PMT5931B is available at Aetrix Electronics and suitable for switching power supplies, overvoltage protection circuits, precision reference sources, and temperature-stable bias generators requiring stable component supply and traceable sourcing.

Supply support for 1PMT5931B 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 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 designed for high-power-density surface-mount voltage regulation and clamping in harsh-environment power systems where thermal management and long-term stability are critical.

FAQ

What is the zener voltage tolerance for 1PMT5931B?

The standard 1PMT5931B has a zener voltage tolerance of ±5% at 18 V. Tighter tolerances of ±2% (suffix C) and ±1% (suffix D) are available upon request. Voltage is measured at 20.8 mA test current with tab temperature held at 30°C for 20 seconds prior to reading.

How is thermal performance defined for 1PMT5931B?

The 1PMT5931B has a junction-to-tab thermal resistance of 30°C/W. This value assumes TAB 1 is soldered to a minimum 100 mm² copper pad with two thermal vias. At 60°C tab temperature, the device sustains 3.0 W DC dissipation - exceeding typical SMD Zeners by 3×.

Can 1PMT5931B be used in place of through-hole 1N5245B?

No - while both regulate at ~18 V, the 1PMT5931B is a surface-mount Powermite® device with tab-as-cathode and 3.0 W rating, whereas the 1N5245B is a 500 mW through-hole device in DO-35. Their thermal paths, mounting methods, and surge capabilities differ fundamentally; direct substitution requires PCB redesign.

What does the "B" suffix mean in 1PMT5931B?

The "B" suffix in 1PMT5931B indicates compliance with Microsemi's standard Powermite® Zener family specifications, including DO-216 mechanical outline, EIA-481 tape-and-reel packaging (3,000 pcs per 7-inch reel), and ±5% zener voltage tolerance. It is not a revision code or RoHS indicator.

Is 1PMT5931B suitable for automotive applications?

The 1PMT5931B meets AEC-Q200 stress test requirements for passive components when qualified per Microsemi's automotive-grade screening flow. Its -55°C to +150°C operating range, >16 kV HBM ESD rating, and flux-free metallic bottom support under-hood use - but final qualification requires customer-specific PPAP submission.