Microchip Technology 1PMT5937/TR13

Overview

1PMT5937/TR13 from Microsemi is a 33 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 11.4 mA test current (IZT), 33 Ω dynamic impedance (ZZT), and 1 µA max reverse leakage at 25.1 V. It serves as a precision voltage reference or overvoltage clamp in power supply regulation and ESD-protected signal lines.

For engineers reviewing the 1PMT5937/TR13 datasheet, 1PMT5937/TR13 pinout, 1PMT5937/TR13 application, or 1PMT5937/TR13 equivalent, key selection criteria include its 33 V nominal Zener voltage, 3.0 W thermal capability via metallic tab, DO-216 mechanical outline, >16 kV HBM ESD rating, and compatibility with automated SMT insertion equipment.

Technical Context

This Zener diode operates in reverse breakdown to maintain stable voltage across a load under varying current conditions. Its Powermite® package integrates a full metallic bottom and locking tab that functions as both mechanical anchor and thermal path to PCB copper, enabling 30°C/W junction-to-tab thermal resistance.

The device is characterized at TL = 30°C with IZT = 11.4 mA, exhibits low knee impedance (ZZK = 0.25 Ω), and maintains tight regulation up to IZM = 74.3 mA - derived from its 3.0 W power limit and 33 V nominal voltage.

Key Specifications

Pinout & Package

Package: Powermite® (DO-216), molded surface-mount package with full metallic bottom and integral locking tab (TAB 1 = cathode). Cathode identified by TAB 1; mounting orientation unrestricted.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMCJ33A and BZX84-C33, the 1PMT5937/TR13 uniquely combines 3.0 W DC power handling, 33 Ω dynamic impedance, and integrated thermal tab - making it the only choice among the three for continuous-voltage-reference designs requiring both precision and power robustness.

Availability

1PMT5937/TR13 is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, medical sensor interfaces, and telecom line protection requiring stable component supply and traceable sourcing.

Supply support for 1PMT5937/TR13 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 voltage regulation and transient protection in harsh-environment systems where thermal performance and assembly reliability are critical.

FAQ

What is the Zener voltage tolerance for 1PMT5937/TR13?

The 1PMT5937/TR13 has a standard Zener voltage tolerance of ±5% at 33 V, measured at 11.4 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 networks and must be accounted for in loop gain calculations for 1PMT5937/TR13-based designs.

How is thermal performance managed in the 1PMT5937/TR13 package?

The 1PMT5937/TR13 uses a Powermite® package with a full metallic bottom and integral locking tab (TAB 1) that serves as both mechanical anchor and primary thermal path. Its specified junction-to-TAB1 thermal resistance is 30°C/W, enabling direct thermal coupling to PCB copper. For reliable operation, TAB 1 must be soldered to ≥1 square inch of 2-oz copper to achieve the rated 3.0 W dissipation at 60°C tab temperature.

Can 1PMT5937/TR13 be used as a replacement for through-hole Zener diodes like 1N5256B?

No - the 1PMT5937/TR13 is not a drop-in replacement for 1N5256B due to fundamental differences in package, thermal path, and power derating. While both are 33 V Zeners, 1N5256B is a 0.5 W through-hole device in DO-35, whereas 1PMT5937/TR13 delivers 3.0 W in a surface-mount Powermite® package with tab-based thermal conduction. Board redesign and thermal validation are required when substituting 1PMT5937/TR13 for 1N5256B.

What is the maximum reverse leakage current for 1PMT5937/TR13 at rated voltage?

The maximum reverse leakage current for 1PMT5937/TR13 is 1 µA at 25.1 V (76% of nominal 33 V), measured at TL = 30°C. This low leakage supports ultra-low-power applications such as battery-operated sensor nodes and always-on monitoring circuits. Exceeding 25.1 V increases leakage exponentially; operation above 33 V should be limited to transient events only.

Is 1PMT5937/TR13 compatible with lead-free reflow profiles?

Yes - the 1PMT5937/TR13 Powermite® package is qualified for standard lead-free reflow profiles (JEDEC J-STD-020), including peak temperatures up to 260°C. Its molded construction and metallic tab withstand thermal cycling without delamination or solder joint fracture. The device is supplied in EIA-481-compliant tape-and-reel format (TR13 = 13-inch reel, 12,000 pieces), ready for high-volume SMT assembly.