1N4728UR-1/TR

Overview

The Microchip Technology 1N4728UR-1/TR is a surface mountable 1.0 W glass Zener diode in the DO-213AB (MELF) package. It provides a nominal Zener voltage of 3.3 V with a standard tolerance of ±5%. The device operates within a temperature range of -65°C to +175°C and features a maximum reverse current of 100 µA at 1 V. Electrical characteristics include a test current of 76 mA, a dynamic impedance of 10 Ω at IZT, and a maximum regulator current of 276 mA at TA = 50°C.

Feature Summary

• Hermetically sealed glass MELF package suitable for high reliability applications
• Surface mount design ideal for high density mounting with low parasitic requirements
• Inherently radiation hard per MicroNote 050
• Regulates voltage over a broad operating current and temperature range

Applications

• Voltage regulation in high density electronic circuits
• High reliability applications requiring source control drawings
• Radiation-hardened circuit designs

Procurement Notes

Verify the specific suffix configuration against official documentation to confirm tolerance and packaging details. Confirm RoHS compliance status if required by the application. Check for availability of screening options such as MIL-PRF-19500 variants if military specifications are necessary. Ensure the ordering part number matches the desired voltage tolerance and tape & reel quantity.

Selection Notes

Select this component for applications requiring a 3.3 V reference in a surface mount form factor. The DO-213AB package offers a leadless design beneficial for space-constrained layouts. Consider the thermal resistance of 50 °C/W junction to end cap when designing heat dissipation paths. Verify that the 1.0 W power dissipation rating meets the steady-state requirements of the target circuit under expected ambient conditions.

Part Context

This device belongs to the 1N4728UR thru 1N4764AUR series of surface mount 1.0 W glass Zener diodes. It is electrically equivalent to the JEDEC registered 1N4728A thru 1N4764A series but utilizes the DO-213AB outline instead of the DO-41 axial package. The series covers Zener voltages from 3.3 V to 100 V, providing a wide selection for various regulation needs.

Replacement Considerations

Equivalent axial-leaded parts include the 1N4728A series. Surface mount equivalents are available as SMAJ4728A. Alternate naming includes MLL4728A.