# Axial diode

An axial leaded diode with formed leads, lying on the board or standing up. The package outlines are Vishay's: DO-35 (DO-204AH, a glass body), DO-41 (DO-204AL), DO-15 (DO-204AC), DO-201AD and P600, each from a Vishay data sheet.

Lead 1, the cathode at the band, is at the origin. Lead 2, the anode, is at +X by `pitch`, and both leads go down through the board, `tail` below it.

- **Horizontal.** The body lies on the board along X, centred between the leads, with its band toward lead 1.
- **Vertical.** The body stands on the board. With `up = "anode"` it stands over lead 1, and with `up = "cathode"` over lead 2. The top lead clears the body's top, turns over and comes back down at the other hole.

| Package | Body Ø | Body length | Lead Ø | Sheet |
|---|---|---|---|---|
| DO-35 (DO-204AH) | 1.5–1.75 | 3.4 max | 0.55 max | 1N4148 |
| DO-41 (DO-204AL) | 2.0–2.7 | 4.1–5.2 | 0.71–0.86 | 1N4001 |
| DO-15 (DO-204AC) | 3.3–3.5 | 6.15–6.55 | 0.71–0.86 | P6KE6.8A |
| DO-201AD | 4.8–5.3 | 7.2–9.5 | 1.22–1.32 | 1N5400 |
| P600 | 8.6–9.1 | 8.6–9.1 | 1.22–1.32 | P600A |

The part uses the middle of each range. Where the sheet gives only a maximum (DO-35's length and lead), it uses that value.

## Source

Vishay data sheets, from vishay.com:

- Vishay Semiconductors, **1N4148**, document 81857, Rev. 1.6, 07-Nov-2024, page 3, "PACKAGE DIMENSIONS in millimeters (inches): DO-35 (DO-204AH)". The cathode band is black, according to page 1.
- Vishay General Semiconductor, **1N4001 thru 1N4007**, document 88503, revision 29-Apr-2020, page 4, "PACKAGE OUTLINE DIMENSIONS: DO-41 (DO-204AL)".
- Vishay General Semiconductor, **P6KE6.8A thru P6KE540A**, document 88369, revision 27-Sep-2021, page 5, "DO-15 (DO-204AC)".
- Vishay General Semiconductor, **1N5400 thru 1N5408**, document 88516, revision 19-Dec-2025, page 4, "DO-201AD".
- Vishay General Semiconductor, **P600A thru P600M**, document 88692, revision 19-Dec-2025, page 3, "P600".

The moulded packages carry a colour band at the cathode end ("color band denotes cathode end"). The leads are 25.4 min long before forming.

**Proportions, for looks only.** The sheets draw the body but dimension only its diameter and length:

- The body's end edges are rounded by 0.25 x the radius, or 0.45 x on the DO-35's glass.
- The cathode band is 0.18 x the length wide, starting at the cathode end's rounding.
- The leads are bent with a radius of one lead diameter. On a vertical part, the top lead rises 2 lead diameters + 1 above the body before it turns.
- Materials are for looks and a rough mass:
  - DO-35 is borosilicate glass in amber, with a black band.
  - The moulded packages are epoxy. Nylon (PA6) is the nearest in the list. They are black with a light band.
  - The leads are tin-plated copper.

## Catalogue models

The catalogue's `D_<package>_P<pitch>mm_<Horizontal|Vertical_AnodeUp|Vertical_CathodeUp>` models name a JEDEC package (or the P600 / R-6 case) and a pitch, and 29 of them map.

On the reference models, lead 1 is at the origin. A horizontal body lies between the leads. A vertical body stands over lead 1 when the anode is up and over lead 2 when the cathode is up. The pitch is the named one.

Measured on six reference models (body Ø x length, lead Ø):

| Model | Measured | Vishay's sheet |
|---|---|---|
| DO-41 P7.62 horizontal | 2.72 x 5.2, 0.80 | 2.0–2.7 x 4.1–5.2, 0.71–0.86 |
| DO-35 P7.62 horizontal | 2.02 x 4.0, 0.50 | 1.5–1.75 x 3.4 max, 0.55 max |
| DO-15 P10.16 horizontal | 3.62 x 7.6, 0.90 | 3.3–3.5 x 6.15–6.55, 0.71–0.86 |
| DO-201AD P12.70 horizontal | 5.22 x 9.5, 1.30 | 4.8–5.3 x 7.2–9.5, 1.22–1.32 |
| P600 P12.70 horizontal | 9.12 x 9.1, 1.30 | 8.6–9.1 x 8.6–9.1, 1.22–1.32 |
| DO-41 P2.54 vertical, anode up / cathode up | 2.72 x 5.2 | as above |

The models are drawn at or beyond the largest body that each package allows. The DO-35 and DO-15 models are larger than Vishay's maximums: the DO-35 by 0.27 in diameter and 0.6 in length, and the DO-15 by 0.12 in diameter and 1.05 in length.

The names name the package, so they map to Vishay's outline of that package, and the pitch and lead order are as named. The bodies lie on the board, where the models raise them about 0.6.

Left as "no table read yet" until a sheet is read: 5KP, 5KPW, 5W, A-405, DO-201, DO-201AE, DO-27, DO-34, T-1, DO-247 and the bridge rectifiers.