Microchip Technology 1PMT5931C/TR7

Overview

1PMT5931C/TR7 from Microsemi is a 18 V, ±2% tolerance Zener diode in Powermite® surface-mount package, rated for 3.0 W DC power dissipation at TAB 1 = 60°C, with 12 Ω dynamic impedance at 20.8 mA test current and thermal resistance of 30°C/W junction-to-tab. It serves as a precision voltage reference or overvoltage clamp in DC power rails and regulator feedback paths.

For engineers reviewing the 1PMT5931C/TR7 datasheet, 1PMT5931C/TR7 pinout, 1PMT5931C/TR7 application, or 1PMT5931C/TR7 equivalent, key selection criteria include Zener voltage tolerance (±2%), power derating above 60°C, low knee impedance (650 Ω at 0.25 mA), ESD rating (>16 kV HBM), and compatibility with automated SMT placement equipment.

Technical Context

This device operates as a two-terminal voltage-regulating diode with sharp reverse breakdown at nominal 18 V. Its Powermite® package integrates a full metallic bottom and locking tab to enhance thermal conduction and mechanical stability during reflow soldering.

Electrical behavior is defined at TL = 30°C with 20.8 mA test current; Zener voltage shifts with temperature (TCZ not specified in source), and dynamic impedance rises significantly below IZK = 0.25 mA, where knee impedance is 650 Ω.

Key Specifications

Pinout & Package

Package: Powermite® surface-mount molded package with full metallic bottom and integral heat-sink locking tab; cathode designated by TAB 1; mounting position unrestricted.

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 1PMT5931C/TR7 delivers superior DC regulation accuracy (±2%), higher continuous power handling (3.0 W vs. 300 mW), and lower dynamic impedance (12 Ω), making it optimal for precision voltage reference and sustained overvoltage clamping in industrial power systems.

Availability

1PMT5931C/TR7 is available at Aetrix Electronics and suitable for industrial power supplies, motor drive feedback circuits, and sensor biasing applications requiring stable component supply and long-term manufacturability.

Supply support for 1PMT5931C/TR7 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 was designed for high-power density surface-mount voltage regulation in space-constrained industrial and automotive environments where thermal performance and assembly reliability are critical.

FAQ

What is the Zener voltage tolerance of 1PMT5931C/TR7?

The "C" suffix in 1PMT5931C/TR7 denotes ±2% Zener voltage tolerance at 20.8 mA test current and TAB 1 temperature of 30°C. This is tighter than the standard ±5% (B suffix) and supports precision regulation applications where voltage accuracy is critical. The 1PMT5931C/TR7 achieves this via tighter binning during manufacturing and is verified per Microsemi's test protocol outlined in MSC0995.PDF.

How is thermal management handled for 1PMT5931C/TR7?

The 1PMT5931C/TR7 uses its metallic TAB 1 as the primary thermal path, with a specified junction-to-tab thermal resistance of 30°C/W. To maintain rated 3.0 W dissipation, TAB 1 must be soldered to a minimum 100 mm² copper area on the PCB. Derating begins above 60°C ambient or case temperature, following a linear curve to zero power at 150°C junction temperature. The Powermite® package's full metallic bottom ensures reliable thermal conduction without flux entrapment.

Is 1PMT5931C/TR7 compatible with lead-free reflow processes?

Yes, the 1PMT5931C/TR7 Powermite® package is qualified for standard lead-free reflow profiles, including JEDEC J-STD-020-compliant peak temperatures up to 260°C. Its molded construction and metallic bottom withstand thermal cycling without delamination or solder joint integrity loss. The device is shipped in EIA-481-compliant tape-and-reel format (7″ reel, 3,000 pieces), optimized for automated SMT placement equipment.

What does the "TR7" suffix indicate in 1PMT5931C/TR7?

The "TR7" suffix specifies packaging: tape-and-reel in a 7-inch reel containing 3,000 units, compliant with EIA Standard 481. This format ensures compatibility with high-speed pick-and-place machines and supports just-in-time manufacturing workflows. It does not affect electrical specifications - all performance parameters of the 1PMT5931C/TR7 remain identical to the same die in alternate packaging formats.

Can 1PMT5931C/TR7 be used in bidirectional ESD protection?

No - the 1PMT5931C/TR7 is a unidirectional Zener diode configured as cathode-to-tab (TAB 1). It conducts only in reverse breakdown (cathode positive relative to anode) and lacks symmetrical clamping capability. For bidirectional ESD protection, dedicated TVS diodes such as SMAJ18A or ESD-rated dual-rail arrays are required. The 1PMT5931C/TR7's >16 kV HBM rating applies only to human-body model ESD events on the cathode terminal, not system-level bidirectional transients.