1N4477

Single Zener Diodes Overview

The Microchip Technology 1N4477 is a 33 V Zener voltage regulator diode with a 1.5 W power dissipation rating and DO-41 axial lead package. It operates within a junction temperature range of -65 °C to +175 °C. The device features a maximum dynamic impedance of 25 Ohms at a test current of 7.5 mA, with a maximum reverse leakage current of 50 nA at 26.4 V. Standard commercial versions offer ±5% tolerance, while military qualified variants (JAN, JANTX, JANTXV, JANS) provide tighter tolerances.

Single Zener Diodes Feature Summary

• Hermetically sealed voidless glass construction with internal metallurgical bonds for robust performance in high-reliability environments.
• Military qualification per MIL-PRF-19500/406 across JAN, JANTX, JANTXV, and JANS reliability levels.
• Inherently radiation hard and non-sensitive to electrostatic discharge (ESD).
• Triple-layer passivation coating on the blue-coated body.

Single Zener Diodes Applications

• Voltage regulation over broad operating current and temperature ranges.
• High-reliability applications where component failure cannot be tolerated.
• Temperature compensated Zener reference circuits.

Single Zener Diodes Procurement Notes

Verify the specific suffix code to confirm the required reliability level and tolerance. Commercial versions lack military qualification, whereas JAN, JANTX, JANTXV, and JANS designations indicate compliance with MIL-PRF-19500/406 standards. Confirm RoHS compliance requirements, as this status applies only to commercial grade offerings. Ensure the ordering suffix matches the exact electrical tolerance needed for the circuit design.

Single Zener Diodes Selection Notes

Select the 1N4477 for applications requiring a stable 33 V reference with a 1.5 W power handling capability. Choose military qualified suffixes when operation in extreme temperatures or harsh environments is necessary. Verify that the 25 Ohm dynamic impedance meets the noise and stability requirements of the load. Consider the DO-41 through-hole package constraints during PCB layout planning.

Single Zener Diodes Part Context

This component belongs to the 1N4460–1N4496 series of industry-recognized 1.5 Watt Zener voltage regulators. The series covers nominal voltages from 3.3 V to 200 V. These devices utilize a voidless hard glass package with tungsten slugs to ensure thermal stability and hermetic sealing. The series is designed to meet stringent military specifications for long-term durability.

Single Zener Diodes Replacement Considerations

Substitutes must match the 33 V nominal Zener voltage, 1.5 W power rating, and DO-41 package dimensions. Verify that alternative components meet the same MIL-PRF-19500/406 qualification if military reliability is required. Check for equivalent dynamic impedance and leakage current specifications to ensure circuit compatibility.

Single Zener Diodes FAQ

What is the maximum steady-state power dissipation?

The maximum steady-state power dissipation is 1.5 W at a lead temperature of +112 °C.

How is polarity indicated on the device?

Polarity is indicated by a band on the body of the diode, which marks the cathode end.

Is the device sensitive to electrostatic discharge?

No, the device is non-sensitive to ESD per MIL-STD-750 method 1020.