Microchip Technology 1PMT5942C/TR13

Overview

1PMT5942C/TR13 from Microsemi is a 51 V, ±1% tolerance Zener diode in Powermite® surface-mount package with 3.0 W power dissipation, 7.3 mA test current, and 70 Ω dynamic impedance at 30°C case temperature - used for precision voltage regulation in power supply feedback loops and overvoltage protection circuits.

For engineers reviewing the 1PMT5942C/TR13 datasheet, 1PMT5942C/TR13 pinout, 1PMT5942C/TR13 application, or 1PMT5942C/TR13 equivalent, key selection criteria include zener voltage tolerance (±1%), thermal resistance (30°C/W), ESD rating (>16 kV HBM), low reverse leakage (≤1 µA at 38.8 V), and compatibility with automated SMT assembly per EIA-481 tape-and-reel packaging.

Technical Context

This Zener diode operates as a two-terminal voltage reference device with cathode designated by TAB 1, requiring no external biasing. Its full metallic bottom and integral heat sink locking tab enable direct thermal conduction to PCB copper, supporting stable 3.0 W dissipation when TAB 1 is mounted on ≥1 sq-in copper area.

The device exhibits tight voltage regulation under DC conditions: V_Z = 51.0 V ±1% at I_ZT = 7.3 mA, with knee current I_ZK = 0.25 mA and corresponding knee impedance Z_ZK = 1100 Ω - enabling reliable turn-on behavior even at low bias currents.

Key Specifications

Pinout & Package

Powermite® package features a two-terminal configuration with cathode identified by TAB 1; anode is the molded body side. The full metallic bottom serves as both thermal path and mechanical anchor, while the locking tab enhances solder joint reliability during thermal cycling.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5942C and BZX84-C51, the 1PMT5942C/TR13 delivers superior thermal performance and tighter tolerance in a surface-mount form factor - making it the only option among the three capable of sustaining 3.0 W dissipation in automated production environments.

Availability

1PMT5942C/TR13 is available at Aetrix Electronics and suitable for switch-mode power supplies, overvoltage protection circuits, programmable voltage references, and current source biasing requiring stable component supply and consistent ±1% zener voltage tolerance.

Supply support for 1PMT5942C/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 designed specifically for high-power density surface-mount voltage regulation and protection in harsh-environment power systems where thermal management and long-term stability are critical.

FAQ

What is the zener voltage tolerance for 1PMT5942C/TR13?

The 1PMT5942C/TR13 has a nominal zener voltage of 51.0 V with a tolerance of ±1%, as indicated by the "C" suffix per Microsemi's naming convention. This tolerance is verified at 7.3 mA test current and 30°C case temperature. The 1PMT5942C/TR13 achieves this precision via post-process screening and is distinct from the ±5% 1PMT5942B variant.

How is thermal management handled for 1PMT5942C/TR13 in PCB layout?

The 1PMT5942C/TR13 relies on TAB 1 as its primary thermal path, with a specified junction-to-TAB thermal resistance of 30°C/W. To achieve full 3.0 W power dissipation, TAB 1 must be soldered to ≥1 square inch of 2-oz copper with thermal vias to inner layers. The full metallic bottom and locking tab enhance conduction - unlike plastic-bottom SMD Zeners that require external heatsinks.

Is 1PMT5942C/TR13 compatible with lead-free reflow processes?

Yes, the 1PMT5942C/TR13 is qualified for standard lead-free reflow profiles, including peak temperatures up to 260°C for 10 seconds. Its Powermite® package uses matte tin-plated terminals and thermally stable molding compound. The device meets JEDEC J-STD-020 moisture sensitivity level 1, eliminating bake requirements prior to assembly.

What does the "TR13" suffix indicate in 1PMT5942C/TR13?

The "TR13" suffix denotes tape-and-reel packaging per EIA-481 standard on a 13-inch reel containing 12,000 units. This format is optimized for high-volume SMT placement equipment. It is distinct from "TR7", which indicates a 7-inch reel with 3,000 units. Both share identical electrical and thermal specifications for the 1PMT5942C/TR13 device.

Can 1PMT5942C/TR13 be used as a replacement for 1N5942C in existing designs?

No - although both share 51 V ±1% zener voltage, the 1PMT5942C/TR13 uses a Powermite® (DO-216) surface-mount package, whereas 1N5942C is DO-41 through-hole. Their footprints, thermal paths, and assembly methods are incompatible. A redesign of the PCB land pattern and thermal relief is required to migrate from 1N5942C to 1PMT5942C/TR13.