5 ns reverse recovery — switching-speed anchor for the BOM
The 1N4148UBCCC/TR is a Microchip Technology fast-recovery diode pair in a common-cathode configuration, specified with a reverse recovery time (trr) of 5 ns. That 5 ns figure means the diode can switch off a forward current of 100 mA or more in under half a microsecond — fast enough to clip ringing in a high-frequency rectifier or catch a flyback pulse in a 500 kHz switching converter without the diode staying on long enough to short the secondary. The 25 nA reverse leakage at 20 V is typical for a small-signal switching diode — negligible for most signal-level work but worth noting if the circuit biases the diode near its reverse breakdown at elevated temperature.
UBC package — no-lead SMD, no leads to inspect
The 3-SMD no-lead package (Microchip's UBC code) is a surface-mount, leadless ceramic or plastic body with solder pads on the bottom — no gull-wing or J-bend leads to bend or inspect. The joint is hidden under the part, so X-ray inspection or a boundary-scan test is the only way to confirm solder wetting after reflow. The wide range also means the part can be stored in a non-temperature-controlled warehouse without derating concerns.
Active production — no LTB clock ticking
If a second-source is needed, the 1N4148 family has many pin-compatible variants from multiple manufacturers in similar SMD packages — but the UBC footprint is specific to Microchip's 3-SMD no-lead outline, so a direct drop-in replacement requires matching that exact package code.