Abstract: A transmit line driver with selectable slew rates and a common mode idle state comprises a capacitor array of selectable capacitors coupled between a line driver and a pre-driver wherein a slew rate may be selected by the selectable capacitors. A common mode idle state is provided by coupling a selectable switch (MOSFET in the described embodiment) to a mirror device that provides a bias current to the pre-driver wherein, when the bias current is removed by the switch, the pre-driver produces an output signal that is equal to the supply voltage for the circuit. Accordingly, a differential pair of the line driver are both biased on and provide a common mode idle state. The common mode idle state is equal to one half of an output signal magnitude for a logic one.

Abstract: A phase locked loop having a voltage-controlled oscillator is adjusted to compensate for process variations in the formation of the phase locked loop. In each instance of the phase locked loop, the center frequency of the voltage-controlled oscillator is adjusted using a bias signal while holding the control voltage of the voltage-controlled oscillator at zero. Then, the control voltage of the voltage-controlled oscillator is set to a different value and the gain of the voltage-controlled oscillator is adjusted.