1N5387B

Overview

The Microsemi Corporation 1N5387B is a silicon 5.0-watt Zener diode with a nominal voltage of 190 V and ±5% tolerance. It features a T-18 axial leaded plastic package, operating from -65°C to +150°C. Electrical characteristics include a maximum dynamic impedance of 450 ohms at 5.0 mA test current, a maximum reverse leakage current of 0.5 µA at 137 V, and a maximum regulator current of 25 A. The device withstands a surge current of 1850 A (8.3 ms) and has a thermal resistance of 25°C/W junction-to-lead.

Feature Summary

• Provides stable voltage regulation across a broad operating current and temperature range
• Withstands high surge stresses and operates at high maximum DC currents when adequately heat sunk
• Features flexible axial-lead mounting terminals for standard through-hole integration
• Moisture classification Level 1 requiring no dry pack storage

Applications

• Voltage regulation circuits in industrial equipment
• Overvoltage protection for power supply inputs
• High-reliability military and aerospace applications using screened prefixes

Procurement Notes

Verify the specific suffix letter on the part number to confirm the exact voltage tolerance before procurement. Confirm that the required screening level matches the base JEDEC registration or requires an added prefix identifier. Ensure adequate heat sinking is designed into the application to support the 5-watt power dissipation rating.

Selection Notes

Select this component for applications requiring a 190 V regulation point within a 5-watt power envelope. Consider the 450-ohm dynamic impedance for circuit stability requirements. Verify that the T-18 package dimensions fit the target PCB layout and that the operating temperature range meets environmental specifications.

Part Context

This component belongs to the 1N5333B through 1N5388B series of JEDEC registered silicon Zener diodes manufactured by Microsemi's Scottsdale Division. The series covers a voltage selection from 3.3 to 200 volts. The 'B' suffix specifically denotes a standard ±5% voltage tolerance.

Replacement Considerations

Surface mount equivalents are available as SMBJ5333 to SMBJ5388B or SMBG5333B to SMBG5388B. Military equivalent screening levels can be obtained by adding MQ, MX, or MV prefixes to the part number.

FAQ

What does the 'B' suffix indicate for the 1N5387B?

The 'B' suffix identifies the device as having a standard voltage tolerance of plus or minus 5%.

How is the polarity indicated on the 1N5387B?

The cathode is indicated by a band on the plastic body. The diode must be operated with the banded end positive with respect to the opposite end.