The BB639C from Infineon Technologies is a Varactor Diode with Capacitance 39.0 pF (CT1), 30.2 pF(CT2), Capacitance Ratio 11.1 (2/25V), Forward Continous Currenrt 20.0 mA, Peak reverse voltage 30 V, Reverse Voltage 30 V. Tags: Surface Mount. More details for BB639C can be seen below.