Military-qualified Schottky in a no-lead SMD package
The 1N5711UB is a Schottky barrier diode screened to MIL-PRF-19500/444, the military specification for small-signal Schottky diodes. The UB suffix denotes a 3-terminal, no-lead surface-mount package — the die sits in a ceramic cavity with solderable pads on the bottom face, not wire-bonded to a leadframe. This construction eliminates the parasitic inductance of a conventional leaded package and keeps the capacitance at 2 pF at zero bias, measured at 1 MHz. Rated for 50 V DC reverse voltage and 33 mA average rectified current, the diode is intended for low-power, high-frequency detector and mixer circuits where the Schottky's fast switching and low forward voltage (1 V maximum at 15 mA) matter more than current handling.
Parametric profile for RF and detector applications
The 2 pF capacitance at zero bias sets the upper frequency limit: in a 50-ohm system the capacitive reactance at 1 GHz is about 80 ohms, so the diode still presents a reasonable impedance match for detector and mixer designs up to several gigahertz. The forward voltage of 1 V at 15 mA is typical for a small-signal Schottky — the barrier height is optimised for low turn-on rather than low leakage. For applications requiring lower Vf at the expense of higher leakage, a germanium or hot-carrier diode would be a different trade; the 1N5711UB sits on the low-leakage side of the Schottky family.