The BB831 from Infineon Technologies is a Varactor Diode with Capacitance 8.8 pF (CT1), Capacitance Ratio 8.6 (1/28V), Forward Continous Currenrt 20.0 mA, Peak reverse voltage 30 V, Reverse Voltage 30 V. Tags: Surface Mount. More details for BB831 can be seen below.