Diodes Incorporated 1N4937GL-T

Overview

1N4937GL-T from Diodes Incorporated is a 1.0A fast recovery glass passivated rectifier diode with 600V peak repetitive reverse voltage, 1.2V forward voltage at 1.0A, and 200ns reverse recovery time, used in AC/DC input stage rectification for offline switch-mode power supplies.

For engineers reviewing the 1N4937GL-T datasheet, 1N4937GL-T pinout, 1N4937GL-T application, or 1N4937GL-T equivalent, key selection criteria include VRRM rating margin for surge tolerance, trr for high-frequency switching efficiency, thermal resistance for PCB layout derating, and DO-41 package compatibility with legacy through-hole designs.

Technical Context

This device employs a diffused junction silicon die with glass passivation to achieve stable reverse leakage (5.0μA @ 25°C) and robust surge capability (30A peak, 8.3ms half-sine). Its 200ns trr enables operation up to ~100kHz in flyback and forward converters without excessive switching loss.

The DO-41 package delivers 100K/W junction-to-ambient thermal resistance under standard PC board mounting (9.5mm lead length), requiring careful trace width and copper pour design to sustain 1.0A average current at 75°C ambient per derating curve.

Key Specifications

Pinout & Package

Package: DO-41 molded plastic case (UL 94V-0), axial leads with cathode band marking. Weight: 0.35g.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fast recovery rectifier applications.

Compared with STTH1R06 and MUR1060, the 1N4937GL-T balances moderate trr and VF for cost-sensitive, naturally cooled AC/DC stages where 200ns recovery suffices and DO-41 footprint is mandatory.

Availability

1N4937GL-T is available at Aetrix Electronics and suitable for AC/DC adapter input rectification, industrial control power supplies, and LED driver bulk capacitor charging requiring stable component supply and long-lifecycle support.

Supply support for 1N4937GL-T 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the US.

The 1N493xG series targets cost-optimized, high-volume power conversion applications where reliability, surge robustness, and RoHS compliance are essential in legacy through-hole designs.

FAQ

What is the maximum allowable junction temperature for continuous operation?

The 1N4937GL-T has an operating junction temperature range of –65°C to +150°C. For reliable long-term operation at 1.0A average current, the junction temperature must remain below 150°C, which requires maintaining ambient temperature ≤75°C with proper PCB copper area and lead length per the derating curve.

Is the 1N4937GL-T suitable for use in a full-wave bridge configuration?

Yes - four 1N4937GL-T diodes can form a discrete full-wave bridge rectifier. Each device handles one quadrant with its 600V VRRM rating sufficient for 230VAC input (peak ~325V), and the 30A IFSM rating accommodates typical bridge inrush currents.

How does the glass passivation improve long-term reliability?

Glass passivation forms a hermetic, chemically inert barrier over the silicon die surface, preventing oxidation, ion migration, and moisture ingress that cause parametric drift or premature failure-especially critical in humid or thermally cycled environments like outdoor power supplies.

Can this diode replace a 1N4007 in a high-frequency SMPS design?

No - while both are DO-41 rectifiers, the 1N4007 has ~30μs reverse recovery time versus 200ns for the 1N4937GL-T. Using the 1N4007 above ~10kHz causes excessive switching loss and EMI; the 1N4937GL-T is specifically optimized for such higher-frequency applications.