The loop filter output is then applied to an integrated VCO. The VCO output at 2 x fLO is applied to an LO divider, as well as to a programmable PLL divider. The programmable PLL divider is controlled by a - modulator (SDM). The modulus of the SDM can be programmed from 1 to 2047. The active mixer converts the single-ended 50 RF input to a 200 differential IF output. The IF output can operate up to 500 MHz.