What this varactor diode is and where it fits
The Infineon BBY5502VH6327XTSA1 is a single silicon varactor diode in a SC-79 / SOD-523 surface-mount package, designed for voltage-controlled tuning in RF circuits. Its key parameters are a peak reverse voltage of 16 V, a capacitance of 6.5 pF at 10 V and 1 MHz, and a capacitance ratio of 3 measured between 2 V and 10 V reverse bias (C2/C10). The junction temperature range spans -55 to 150 °C, making it suitable for automotive under-hood or industrial sensor-head environments where thermal cycling is severe. Typical applications include VCO tank circuits, bandpass filter tuning, and phase-locked-loop frequency adjustment in telecom infrastructure, automotive RF modules, and portable radios.
Capacitance ratio and what it means for your tuning range
The capacitance ratio of 3 (C2/C10) means the diode's capacitance changes by a factor of three as the reverse bias swings from 2 V to 10 V. That directly sets the frequency tuning range of a VCO or filter.
16 V peak reverse — sizing the tuning supply
The 16 V peak reverse rating sets the maximum DC bias you can apply. In practice, you'll run the tuning voltage below that to leave headroom for ripple and temperature drift.
Package and mounting
The SC-79 / SOD-523 package is a two-pin surface-mount case. The supplier device package is PG-SC79-2. It's a single diode, so the cathode is marked by a bar on the body.
Lifecycle and sourcing
The BBY5502VH6327XTSA1 is listed as Active with ROHS3 compliance. No end-of-life notice or last-time-buy schedule is in effect. It's a current-production Infineon part, so you can qualify it into new designs without worrying about a near-term phase-out.