Diodes Incorporated DL4937-13-F

Overview

DL4937-13-F from Diodes Incorporated is a surface-mount fast recovery rectifier diode optimized for 60 Hz single-phase half-wave AC/DC conversion in power supplies and auxiliary rails, featuring 600 V peak repetitive reverse voltage (VRRM), 1.0 A average forward current (IO) at TT = 75°C, 1.2 V max forward voltage at 1.0 A (VFM), and 200 ns maximum reverse recovery time (trr). It uses a glass-passivated MELF package with RoHS-compliant matte tin plating and is rated for operation from –65°C to +150°C.

For engineers reviewing the DL4937-13-F datasheet, DL4937-13-F pinout, DL4937-13-F application, or DL4937-13-F equivalent, key selection criteria include blocking voltage margin for line-surge immunity, thermal derating under capacitive loads (20% current reduction), fast recovery performance in flyback snubbers, and MELF package compatibility with high-reliability automated placement.

Technical Context

This device operates as a unidirectional power switching element in low-frequency rectification circuits, where its 600 V VRRM supports universal-input (85–265 VAC) offline power supplies. Its 200 ns trr enables reduced switching losses in quasi-resonant converters compared to standard recovery diodes, while the 15 pF typical junction capacitance minimizes high-frequency coupling in EMI-sensitive stages.

The MELF construction provides superior thermal dissipation versus SOD-123 for equivalent current rating, and the glass passivation ensures stable leakage behavior under humid or high-bias stress conditions. The 5.0 µA maximum DC reverse current (IRM) at rated voltage confirms tight process control for standby power optimization.

Key Specifications

Pinout & Package

DL4937-13-F uses a cylindrical MELF (Metal Electrode Leadless Face) package with axial cathode band marking. No discrete pins - terminals are the two end caps of the molded glass-passivated body. Cathode is identified by a single black band; anode is unmarked.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MUR160T3G, DL4937-13-F offers lower conduction loss and smaller footprint but slower recovery; versus VS-1N4937-M3/54, it delivers tighter leakage control critical for battery-backed systems, with identical thermal and layout compatibility.

Availability

DL4937-13-F is available at Aetrix Electronics and suitable for AC/DC adapters, industrial PLC power supplies, UPS chargers, and medical auxiliary supplies requiring stable component supply, RoHS compliance, and MELF-form-factor reliability.

Supply support for DL4937-13-F 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 centers across Asia and manufacturing in China, Taiwan, and the U.S.

The DL493x series targets cost-optimized, high-reliability rectification in consumer, industrial, and computing power supplies, emphasizing robustness, thermal efficiency, and automated assembly compatibility in compact packages.

FAQ

What is the maximum allowable junction temperature for continuous operation?

The DL4937-13-F is rated for continuous operation up to +150°C junction temperature. Derating begins at terminal temperature (TT) above 75°C, with IO linearly decreasing to zero at 150°C per Figure 2 in DS15001 Rev. 5–2. Thermal design must ensure TT ≤ 75°C for full 1.0 A rating.

Can DL4937-13-F replace a 1N4007 in a 12 V transformer-based power supply?

Yes, but only if the circuit operates below 1.0 A average load and does not require >1000 V PIV. DL4937-13-F offers 600 V VRRM (vs. 1N4007's 1000 V), faster recovery (200 ns vs. ~2 µs), and lower VFM (1.2 V vs. ~1.1 V at 1 A), making it better suited for higher-frequency or thermally constrained designs-but insufficient for 230 VAC surge-prone inputs without additional clamping.

Is the MELF package compatible with standard SMT reflow profiles?

Yes-the DL4937-13-F's matte tin finish and glass-passivated structure support industry-standard lead-free reflow profiles (J-STD-020), including peak temperatures up to 260°C for 10 seconds. Its 0.25 g mass and cylindrical geometry require verified nozzle contact and placement accuracy to prevent rolling during pick-and-place.

Does DL4937-13-F support capacitive-input rectifier topologies?

Yes, but with mandatory 20% average current derating per datasheet Note: "For capacitive load, derate current by 20%." At TT = 75°C, this reduces usable IO from 1.0 A to 0.8 A to manage elevated RMS current and peak inverse voltage stress caused by leading-edge inrush into bulk capacitors.