DO-41/DO-15/DO-201AD/R-6 Package Characteristics and Application Selection Guide

An ultrafast recovery diode (URD) or fast recovery epitaxial diode (FRED) is a silicon semiconductor diode characterized by an extremely short reverse recovery time and low reverse recovery charge.

Packaging differences

DO‑15, DO‑41, and DO‑201AD are all common through-hole packages for ultra-fast recovery diodes and other electronic components. Their key differences lie in size, current‑carrying capability, power rating, and application scenarios, with component selection typically guided by circuit space constraints and the required current and power levels.

Key specifications: It features a miniature, upright cylindrical package weighing approximately 0.3 grams. The body diameter ranges from 2.29 to 2.97 mm, with a length of 4.19 to 5.21 mm; the lead diameter is 0.71 to 0.84 mm, and the lead length is fixed at 25.4 mm. Compatible ultra-fast recovery diodes typically have a rated forward current of around 1 A. For example, the UF4004 ultra-fast recovery diode, housed in a DO‑41 package, has a rated forward current of 1 A, a maximum reverse voltage of 400 V, and a reverse recovery time of only 50 ns.

Key specifications: The package size is slightly larger than DO‑41, with a weight of approximately 0.4 g. The body diameter ranges from 2.60 to 3.61 mm, and the length spans 5.85 to 7.63 mm. The lead diameter matches that of DO‑41, at 0.71–0.84 mm, while the lead length is also 25.4 mm. This packaged diode can handle a slightly higher current than DO‑41; for example, certain ultrafast recovery diodes in the DO‑15 package achieve a forward average rectified current of up to 1.5 A and a reverse recovery time as low as about 150 ns.

Key specifications: Among the three, this package is the largest in size, with a weight of approximately 1.0675 grams. The body diameter ranges from 4.79 to 5.30 mm, and the length spans 7.24 to 9.53 mm. The lead diameter has been increased to 0.97–1.07 mm, significantly enhancing its current‑carrying and power‑handling capabilities. When paired with an ultra‑fast recovery diode, it can sustain a forward average rectification current of up to 5 A, with a peak forward surge current reaching 125 A. Its operating temperature range is −55°C to +175°C, and its thermal performance far exceeds that of the first two package types.

Package differences of R-6

R-6 is also known as DO-204AC. It is an axial‑lead package commonly used for high‑current, high‑surge‑capability diodes, well suited to fast‑recovery diodes, rectifier diodes, TVS diodes, and other components, offering distinct advantages in both size and current‑carrying capability.

As an axial‑lead package, its dimensions are significantly larger than those of the DO‑41, DO‑15, and DO‑201AD packages. Taking the compatible FR607 fast‑recovery diode as an example, its overall length is approximately 60 mm, with a body length of 9 mm and a body diameter of 9 mm; the lead diameter is 1.2 mm, and the lead length is 25.4 mm. The robust leads and increased body volume provide a solid foundation for handling high currents and ensuring efficient heat dissipation.