1N4746AP/TR12

Overview

The Microchip Technology 1N4746AP/TR12 is a silicon 1.0-watt Zener diode in the 1N4728AP through 1N4764AP series, housed in a plastic DO-41 (DO-204AL) axial-lead package with a TR12 tape and reel suffix. It provides voltage regulation at a nominal Zener voltage of 18 V with a standard tolerance of ±5%. The device operates within a temperature range of -65°C to +150°C and features a maximum dynamic impedance of 20 Ω at a test current of 14 mA. It includes a maximum reverse current of 5 μA at 13.7 V and supports a steady-state power dissipation of 1.0 watts.

Feature Summary

• Provides stable voltage regulation across a broad operating current and temperature range
• Features flexible axial-lead mounting terminals for standard PCB integration
• Constructed with a void-free transfer molded thermosetting epoxy body meeting UL94V-0 standards
• Moisture classification is Level 1 per IPC/JEDEC J-STD-020B requiring no dry pack

Applications

• Voltage regulation circuits
• Reference voltage sources
• Overvoltage protection

Procurement Notes

Verify the specific ordering suffix against manufacturer documentation to confirm packaging details. The TR12 designation indicates tape and reel packaging; ensure compatibility with automated assembly equipment. Confirm RoHS compliance status if required by project specifications. Cross-reference the part number with official Microchip or Microsemi datasheets to validate electrical parameters before procurement.

Selection Notes

Select this component for applications requiring 18 V regulation with ±5% tolerance. Ensure the circuit design accommodates the 1.0 W power dissipation limit and derating curves. Verify that the axial-lead DO-41 package fits the mechanical constraints. Consider thermal resistance characteristics when designing heat dissipation strategies for high ambient temperatures.

Part Context

This component belongs to the JEDEC registered 1N4728A to 1N4764A series of 1.0 watt Zener diodes. The 'P' suffix denotes plastic encapsulation, which offers lower thermal resistance compared to glass-body options. The series covers a wide voltage selection from 3.3 to 100 volts. Manufacturing history involves Microsemi's Scottsdale Division, now part of Microchip Technology.

Replacement Considerations

Surface mount equivalents are available as SMAJ4746A and MLL4746A. Glass-body versions exist under the same JEDEC numbering but differ in construction. Verify pinout and thermal performance when substituting with other manufacturers' parts.