Microchip Technology 1N3650R

Overview

1N3650R from Microsemi is a high-reliability glass-passivated power rectifier diode rated for 1000 V peak repetitive reverse voltage, 3.3 A average forward current at 150°C case temperature, and 25 A surge current (8.3 ms half-sine). It features glass-to-metal seal construction and is qualified per MIL-PRF-19500/260 for aerospace and defense power conversion systems.

For engineers reviewing the 1N3650R datasheet, 1N3650R pinout, 1N3650R application, or 1N3650R equivalent, key selection criteria include its 1000 V VRRM rating, low thermal resistance of 2.0°C/W, operation across –65°C to +150°C case temperature, and R-suffix indicating reversed polarity (anode-to-stud configuration).

Technical Context

This axial-leaded, stud-mounted rectifier uses a glass-passivated silicon die in a hermetically sealed DO-203AA (DO-4) metal package with threaded anode stud. Its design supports high-voltage DC power supplies where reliability under thermal cycling and transient overvoltage is critical.

The 1N3650R operates with ≤2.2 V forward voltage at 10 A and 25°C junction temperature, and exhibits ≤5 μA reverse leakage at 1000 V and 25°C - enabling stable performance in regulated HVDC outputs and EMI-sensitive military avionics rectification stages.

Key Specifications

Pinout & Package

Package: DO-203AA (DO-4), hermetically sealed glass-to-metal stud-mount metal can with threaded anode terminal (10-32UNF-2A) and cathode lead. The "R" suffix denotes reversed polarity: anode connected to stud, cathode as axial lead.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage power rectifier applications.

Compared with 1N3650 and V60100C-E3/4W, the 1N3650R uniquely combines 1000 V standoff, stud-mount reversibility, MIL-qualified reliability, and hermetic packaging - making it irreplaceable in high-voltage, mission-critical rectification where polarity, ruggedness, and environmental resilience are non-negotiable.

Availability

1N3650R is available at Aetrix Electronics and suitable for high-voltage DC power supplies, aerospace avionics rectification, and defense radar pulse modulators requiring stable component supply across extended product lifecycles.

Supply support for 1N3650R includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microsemi (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog and mixed-signal ICs, discretes, and RF solutions for aerospace, defense, and industrial markets.

The 1N3650R belongs to Microsemi's MIL-PRF-19500/260-qualified power rectifier family, engineered specifically for high-voltage, high-survivability rectification in military and space-grade power systems.

FAQ

What does the "R" suffix mean in 1N3650R?

The "R" suffix in 1N3650R indicates reversed polarity: the anode is connected to the threaded stud, and the cathode is the axial lead. This configuration enables direct anode-to-chassis grounding for EMI suppression and thermal management. Standard 1N3650 has cathode-to-stud polarity. Always verify schematic symbol orientation before layout integration of 1N3650R.

Is 1N3650R suitable for use in space applications?

Yes - the 1N3650R is qualified per MIL-PRF-19500/260 Class B and features a hermetic glass-to-metal seal, –65°C to +150°C operating range, and storage up to +200°C. These characteristics meet baseline requirements for low-earth orbit satellite power conditioning. Radiation hardness data must be obtained separately from Microchip's QML-V documentation for full space qualification of 1N3650R.

What is the maximum allowable torque when mounting the 1N3650R stud?

The maximum allowable torque for the 1N3650R's 10-32UNF-2A threaded stud is 15 inch-pounds, as specified in the official datasheet. Exceeding this value risks damaging the glass-to-metal seal or deforming the internal die attachment. Use calibrated torque tools and apply thread-locking compound only if explicitly approved in the assembly drawing for 1N3650R.

How does the thermal resistance of 1N3650R affect heatsink selection?

With a junction-to-case thermal resistance (RθJC) of 2.0°C/W, the 1N3650R transfers heat efficiently to the mounting surface. For a 3.3 A load at 2.2 V VF, power dissipation is ~7.3 W; using RθJC = 2.0°C/W, junction temperature rise above case is ~14.6°C. Select a heatsink that maintains case temperature ≤150°C under worst-case ambient and airflow - verified via thermal simulation with 1N3650R's actual mounting pressure and interface material.

Can 1N3650R replace 1N3649R in a 800 V design?

No - the 1N3649R is rated for 800 V VRRM, while 1N3650R is rated for 1000 V VRRM. Although 1N3650R exceeds the 800 V requirement, substitution requires validation of forward voltage (VF), reverse leakage (IR), and thermal behavior under identical operating conditions. The 1N3650R's higher VRRM may imply different doping or geometry, affecting softness and switching behavior - review Microchip's 1N3650R SPICE model or test data before replacing 1N3649R with 1N3650R.