Varactor selection for VCO tank circuits
The Infineon BBY5802VH6327XTSA1 is a single silicon tuning diode — a varactor — designed for low-voltage LC-VCO and PLL loop filter applications where the capacitance ratio defines the tuning range. Its 3.5 ratio (C1/C4) and 5.5 pF at 6 V, 1 MHz give a usable capacitance swing from about 1.6 pF at the reverse bias peak up to 5.5 pF near zero bias, which is enough to cover a typical 2:1 frequency range in a tank circuit without pulling the VCO gain too high.
Temperature range and junction rating
The 150°C TJ ceiling means the capacitance drift with temperature stays within the PLL lock-range budget even on a hot engine block.
Housed in the PG-SC79-2 package (SC-79 / SOD-523), a 2-pin surface-mount case. The small footprint suits dense RF front-end layouts where every mm² counts. The tape-and-reel or cut-tape option lets prototype builds and production runs share the same BOM line without requalifying the pick-and-place feeder.
Listed as active with no NRND or EOL flag — qualifies for new designs without a last-time-buy clock.