Diodes Incorporated HER103-T

Overview

HER103-T from Diodes Incorporated is a 1.0A high-efficiency axial-lead rectifier diode with 200V maximum recurrent peak reverse voltage (VRRM), 1.1V typical forward voltage at 1.0A, and 50ns reverse recovery time (trr), designed for AC/DC input stage rectification in offline power supplies and auxiliary power rails.

For engineers reviewing the HER103-T datasheet, HER103-T pinout, HER103-T application, or HER103-T equivalent, key selection criteria include VRRM margin for 230VAC mains-derived designs, low trr to minimize switching loss in quasi-resonant converters, thermal derating above 50°C ambient, and DO-41 mechanical compatibility with legacy through-hole layouts.

Technical Context

This device operates as a single-junction silicon PN rectifier optimized for high-speed switching in line-frequency and high-frequency (up to ~100kHz) flyback and forward converter inputs. Its 50ns trr and 20pF junction capacitance enable reduced turn-off loss compared to standard 1N400x series diodes.

The HER103-T uses a low-leakage epitaxial structure with controlled carrier lifetime to balance reverse recovery speed and reverse leakage-exhibiting only 5.0µA IR at 200V DC blocking and 100µA at 150°C, supporting stable operation in thermally constrained environments.

Key Specifications

Pinout & Package

HER103-T is housed in a DO-41 molded plastic package with axial plated leads; polarity is marked by a cathode band on the body. The device has two terminals: anode and cathode - no internal connections or multi-terminal configuration.

Key Features

Applications

Equivalent & Alternatives

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

Compared with UF1003-T and HER203G, HER103-T offers optimal cost-performance balance for 1.0A, 50–65kHz AC/DC inputs where DO-41 footprint and proven reliability are prioritized over ultra-low VF or higher current headroom.

Availability

HER103-T is available at Aetrix Electronics and suitable for AC/DC adapters, industrial control power supplies, LED driver input stages, and UPS battery charger front-ends requiring stable component supply and long-term manufacturability.

Supply support for HER103-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 Americas.

The HER series targets high-efficiency rectification in cost-sensitive, high-volume power conversion applications-emphasizing speed, low VF, and robust thermal performance in standard packages.

FAQ

What is the maximum allowable junction temperature for HER103-T?

The HER103-T has a specified operating junction temperature range of –65°C to +150°C. Continuous operation at Tj = 150°C is permitted only if IR remains ≤100µA and thermal design ensures steady-state equilibrium-typically requiring PCB copper area ≥100 mm² or forced airflow above 1 m/s for 1.0A load.

Can HER103-T replace 1N4003 in existing designs?

Yes-HER103-T is a direct drop-in replacement for 1N4003 in DO-41 sockets, offering identical pinout and 200V VRRM rating. However, its 50ns trr and 1.1V VF improve efficiency and reduce heat generation, especially in high-frequency or thermally constrained applications where 1N4003's 2.0V VF and 2–4µs trr cause excess loss.

Is HER103-T RoHS compliant and halogen-free?

Yes-HER103-T meets RoHS Directive 2011/65/EU and is halogen-free per IEC 61249-2-21. The DO-41 package uses UL 94V-0 rated molding compound, and lead finishes comply with JEDEC J-STD-609 Class 2a for lead-free solderability.

Does HER103-T require a heatsink at 1.0A continuous current?

At 1.0A and 25°C ambient, no heatsink is required. However, per Fig. 1, derating begins at TA > 50°C: at 70°C ambient, maximum IF(AV) drops to ~0.7A. For 1.0A continuous operation above 50°C, ≥200 mm² of 2-oz copper pour or a small clip-on heatsink is recommended to maintain Tj < 125°C.