Microchip Technology 1N4740PE3/TR12

Overview

1N4740PE3/TR12 from Microsemi is a 10 V, 5% tolerance, 1 W axial-lead silicon Zener diode in DO-41 plastic package, rated for 25 mA test current, 7 Ω dynamic impedance at I_ZT, and 91 mA maximum Zener current at 50 °C. It delivers stable voltage regulation in power supply reference and overvoltage protection circuits across industrial temperature range.

For engineers reviewing the 1N4740PE3/TR12 datasheet, 1N4740PE3/TR12 pinout, 1N4740PE3/TR12 application, or 1N4740PE3/TR12 equivalent, key selection criteria include its 10 V nominal Zener voltage, ±5% tolerance (A-suffix), 1 W power rating at T_L ≤ 105 °C, DO-41 mechanical form factor, and RoHS-compliant matte-tin plating.

Technical Context

This device operates in reverse breakdown to maintain a stable 10 V reference across a wide current range (0.25–91 mA), with low dynamic impedance (7 Ω @ 25 mA) ensuring minimal voltage variation under load transients. Its thermal resistance is 45 °C/W junction-to-lead (3/8″ lead length) and 105 °C/W junction-to-ambient on FR4 board.

The 1N4740PE3/TR12 exhibits a negative temperature coefficient near 10 V (≈ −2 mV/°C per Figure 3), enabling predictable drift compensation in precision references. It is moisture-sensitive Level 1 per J-STD-020B and requires no dry pack, supporting standard reflow and hand-soldering up to 260 °C for 10 s.

Key Specifications

Pinout & Package

DO-41 (DO-204AL) plastic axial-lead package with cathode indicated by band; leads are tin-lead or RoHS-compliant matte-tin plated, solderable per MIL-STD-750 Method 2026.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4740A and BZX55C10, the 1N4740PE3/TR12 offers RoHS compliance and lower thermal resistance in plastic DO-41, making it optimal for modern automated assembly and thermally demanding applications-without requiring PCB redesign.

Availability

1N4740PE3/TR12 is available at Aetrix Electronics and suitable for power supply reference, overvoltage protection, and current source bias applications requiring stable component supply, full traceability, and long-term lifecycle support.

Supply support for 1N4740PE3/TR12 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, RF, and timing solutions for aerospace, defense, and industrial markets.

The 1N47xxAP series was designed specifically for cost-effective, high-volume voltage regulation in commercial and industrial power systems, balancing JEDEC-standard compatibility with enhanced thermal performance in plastic packaging.

FAQ

What is the Zener voltage tolerance of the 1N4740PE3/TR12?

The 1N4740PE3/TR12 has a nominal Zener voltage of 10 V with a ±5% tolerance, as indicated by the "A" suffix in its JEDEC designation. This means the actual measured V_Z falls between 9.5 V and 10.5 V when tested at 25 mA and 25 °C lead temperature. The tolerance remains valid across the full operating temperature range of −65 °C to +150 °C, per Microsemi's published characterization data.

Does the 1N4740PE3/TR12 support automated SMT assembly?

No-the 1N4740PE3/TR12 is an axial-lead DO-41 device supplied in tape-and-reel (TR12) format for through-hole placement, not surface-mount. While the TR12 packaging enables automated pick-and-place, it requires wave soldering or selective soldering-not reflow. For SMT equivalents, consider Microsemi's SMAJ4740A or MLL4740A, which share identical electrical specs in DO-214AC and SOD-123 packages respectively.

What is the maximum steady-state power dissipation for the 1N4740PE3/TR12 on a standard PCB?

The 1N4740PE3/TR12 delivers 1.0 W steady-state power dissipation only when mounted on FR4 with 1 oz copper, 4 mm² pads, and 1 mm × 25 mm traces-conditions yielding 105 °C/W junction-to-ambient thermal resistance. At ambient temperatures above 45 °C, derating applies: power must be reduced linearly to zero at 150 °C ambient, per Figure 1 in the Microsemi datasheet. Lead temperature must remain below 105 °C for full 1 W operation.

How does the 1N4740PE3/TR12 differ from the 1N4740P?

The 1N4740PE3/TR12 adds two key identifiers versus 1N4740P: "e3" denotes RoHS-compliant matte-tin plating (vs. Sn/Pb), and "TR12" specifies EIA-296 tape-and-reel packaging with 12 mm reel width. Electrically and thermally, both share identical Zener voltage, impedance, current ratings, and DO-41 package dimensions. The "e3" suffix ensures compliance with EU RoHS Directive 2011/65/EU and eliminates lead-based solder compatibility concerns.

Can the 1N4740PE3/TR12 be used in bidirectional ESD protection?

No-the 1N4740PE3/TR12 is a unidirectional Zener diode optimized for reverse-bias regulation; its forward voltage is 1.2 V max at 200 mA, but it lacks symmetric clamping characteristics. For bidirectional ESD protection, dedicated TVS diodes like SMAJ10A (unidirectional) or P6KE10CA (bidirectional) are required. The 1N4740PE3/TR12 functions only as a cathode-positive shunt regulator and must not be reverse-connected for protection.