An apparatus includes a switched-capacitor resistor that provides an equivalent resistance that can be used as a reference resistor. The switched-capacitor resistor includes a capacitor and a pair of switches that alternately switch (e.g., open and close) in order to charge and discharge the capacitor. The switching frequency of the switches can be controlled by a clock phase generator that generates non-overlapping pulses. To further control the frequency, a frequency locked loop circuit can also be used.