DO-35 axial footprint and board integration
The 1N4148-1 comes in a DO-204AH (DO-35) axial-lead through-hole package — the same glass-sealed body that has been a staple in MIL-spec and industrial designs for decades. The 0.020-inch diameter leads suit hand-solder or wave-solder assembly; the body length is roughly 0.160 inches, so the seated height above the board is set by the lead bend radius, not the component itself.
20 ns trr — the switching ceiling
Reverse recovery time is 20 ns — this is a standard-recovery switching diode, not a fast-recovery or Schottky type. At 20 ns, the diode can handle switching frequencies into the low-MHz range in clamping or snubbing roles, but the recovery charge will be higher than a Schottky of similar voltage rating. For a 100 kHz flyback clamp, the 20 ns trr is fine; for a 2 MHz synchronous rectifier, the reverse recovery losses will dominate the thermal budget. The forward voltage is 1.2 V maximum at 100 mA — typical for a standard silicon diode of this die size. At 200 mA average rectified current, the conduction loss is about 240 mW; the DO-35 glass body can dissipate that in still air with a 50°C ambient, but above 100°C ambient the junction temperature approaches the 175°C absolute maximum.
Active production — no last-time-buy pressure
Microchip Technology lists the 1N4148-1 as Active — no EOL notice, no NRND flag. This means the die, the glass passivation, and the assembly line are all current. For a BOM that already qualifies this part, there is no urgency to stockpile or qualify a substitute. The part is RoHS non-compliant, so it is restricted to legacy builds or exempt military/aerospace contracts that explicitly allow lead-bearing solder.
The base product number is 1N4148, so cross-references to other manufacturers' 1N4148 variants are possible, but the -1 suffix indicates Microchip's specific screening and test flow; verify the BOM's acceptance of alternate sources before substituting.