Microchip Technology 1N4739PE3/TR8

Overview

1N4739PE3/TR8 from Microsemi is a 1.0 W, 9.1 V ±5% axial-lead Zener diode in DO-41 plastic package, rated for 28 mA test current, 5.0 Ω dynamic impedance at I_ZT, and 7.0 µA reverse leakage at 7.0 V. It delivers stable voltage regulation in power supply reference and overvoltage protection circuits across -65°C to +150°C.

For engineers reviewing the 1N4739PE3/TR8 datasheet, 1N4739PE3/TR8 pinout, 1N4739PE3/TR8 application, or 1N4739PE3/TR8 equivalent, key selection criteria include its 9.1 V nominal Zener voltage, 1 W steady-state dissipation at T_L < 105°C, DO-41 mechanical compatibility, RoHS-compliant matte-tin plating, and 5% tolerance confirmed per JEDEC 1N4739A specification.

Technical Context

This device operates in reverse-biased breakdown mode with a sharp knee at I_ZK = 0.5 mA (Z_ZK = 100 Ω), enabling precise low-current regulation. Its thermal resistance is 45°C/W junction-to-lead (3/8" lead length) and 105°C/W junction-to-ambient on FR4 with defined copper pad geometry.

The 1N4739PE3/TR8 exhibits a negative temperature coefficient near 9.1 V (≈ -2 mV/°C per Figure 3), and supports surge current up to 500 mA (½-sine, 1/120 s) without degradation. It is moisture-sensitive Level 1 per J-STD-020B and requires no dry pack.

Key Specifications

Pinout & Package

DO-41 (DO-204AL) plastic axial-lead package with cathode indicated by color band; terminals are non-polarized for mounting but require banded end to be positive during Zener operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4739A and MMSZ4702T1G, the 1N4739PE3/TR8 offers RoHS compliance without derating, axial-lead mechanical robustness for through-hole reliability, and full 1 W dissipation-making it optimal for industrial power rails where thermal margin and assembly flexibility matter.

Availability

1N4739PE3/TR8 is available at Aetrix Electronics and suitable for power supply reference, overvoltage protection, and signal level shifting applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for 1N4739PE3/TR8 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 and mixed-signal components for aerospace, defense, and industrial markets.

The 1N47xxAP series was designed specifically for general-purpose voltage regulation in cost-sensitive, high-volume industrial power supplies and protection circuits where JEDEC standardization and thermal resilience are critical.

FAQ

What is the Zener voltage tolerance of the 1N4739PE3/TR8?

The 1N4739PE3/TR8 has a nominal Zener voltage of 9.1 V with a ±5% tolerance, consistent with the "A" suffix in its JEDEC designation. This tolerance is verified at 28 mA test current and 25°C lead temperature, and remains stable across its full operating temperature range of -65°C to +150°C. The 1N4739PE3/TR8 meets this spec under both steady-state and transient conditions per Microsemi's REV C datasheet.

Does the 1N4739PE3/TR8 support lead-free soldering processes?

Yes, the 1N4739PE3/TR8 features RoHS-compliant annealed matte-tin plating and is rated for 260°C for 10 seconds per MIL-STD-750 Method 2026. Its "e3" suffix explicitly denotes lead-free termination, making it compatible with standard reflow and wave soldering profiles used in modern electronics manufacturing. The 1N4739PE3/TR8 does not require special pre-bake or moisture sensitivity handling due to its Level 1 J-STD-020B classification.

What is the maximum continuous power dissipation for the 1N4739PE3/TR8?

The 1N4739PE3/TR8 is rated for 1.0 W steady-state power dissipation at a lead temperature (T_L) of ≤105°C with 3/8" (10 mm) lead length from the body. When mounted on an FR4 PCB with specified copper pads, its derated power drops to 1.0 W only below 45°C ambient. Derating curves in Figure 1 of the datasheet confirm linear reduction beyond these points. This 1.0 W rating directly supports the 1N4739PE3/TR8's use in medium-power shunt regulation without heatsinking.

How does the 1N4739PE3/TR8 differ from the glass-body 1N4739G variant?

The 1N4739PE3/TR8 uses plastic (P-suffix) encapsulation, delivering lower thermal resistance (45°C/W vs. ~60°C/W for glass) and eliminating moisture sensitivity concerns. Both share identical electrical specs-9.1 V Zener voltage, 28 mA I_ZT, and 5.0 Ω Z_ZT-but the 1N4739PE3/TR8's DO-41 plastic body improves manufacturability and reliability in humid environments. The 1N4739PE3/TR8 also carries the "e3" RoHS marking, whereas the G-suffix version typically uses Sn/Pb terminations.

Can the 1N4739PE3/TR8 be used in surface-mount designs?

No-the 1N4739PE3/TR8 is an axial-lead DO-41 device and is not compatible with surface-mount assembly. For SMT equivalents, Microsemi offers the SMAJ4739A and MLL4739A in DO-214AC and SOD-123 packages respectively. These alternatives maintain the same 9.1 V Zener voltage but differ in power rating (500 mW), dynamic impedance (≥10 Ω), and thermal performance. The 1N4739PE3/TR8 must be mounted via through-hole holes with 0.020"–0.030" lead diameter.