1N5521D

Overview

The Microchip Technology 1N5521D is a Zener diode designed for voltage regulation applications. It features a nominal Zener voltage of 4.3 V with a tolerance of ±5%. The device has a maximum power dissipation of 500 mW and operates within a temperature range of -65°C to 175°C junction temperature. Key electrical parameters include a Zener impedance of 18 Ohms, a reverse leakage current of 3 µA at 1.5 V, and a forward voltage of 1.1 V at 200 mA. It is housed in the DO-204AH (DO-35) axial through-hole package.

Feature Summary

• Provides stable voltage regulation with a nominal 4.3 V output.
• Capable of handling up to 500 mW of power dissipation.
• Operates reliably across an extended temperature range from -65°C to 175°C.

Applications

• Voltage reference circuits
• Overvoltage protection
• General-purpose voltage regulation

Procurement Notes

Verify the specific suffix 'D' indicates the required ±5% tolerance variant when ordering. Confirm the DO-204AH (DO-35) axial leaded package matches the PCB footprint requirements. Ensure the 500 mW power rating is sufficient for the intended operating conditions. Check for RoHS compliance status if environmental regulations apply to the final assembly.

Selection Notes

Select this component when a precise 4.3 V reference is needed with moderate tolerance. The DO-35 package suits standard through-hole manufacturing processes. Consider the 18 Ohm impedance for load regulation requirements. Verify that the 500 mW power rating accommodates peak currents without exceeding thermal limits.

Part Context

The 1N5521 series belongs to Microchip's line of general-purpose Zener diodes. These components are widely used in electronic designs requiring simple, reliable voltage clamping or referencing. The 1N5521D specifically denotes the version with ±5% voltage tolerance, distinguishing it from tighter tolerance variants like the 1N5521C.

Replacement Considerations

Public confirmed substitutes include 1N5521C and 1N5521D/TR. Verify pinout compatibility and ensure the replacement meets the same 4.3 V nominal voltage and 500 mW power dissipation specifications.