FEATURES
    Power dissipation
        PCM :    0.625W  （T amb=25℃）
    Collector current
        ICM:    -50mA
    Collector-base voltage
        V(BR)CBO  :BF421  -300 V
                             BF423  -250 V
    Operating and storage junction temp erature range
        TJ，Tstg: -55℃to +150℃