In an embodiment a method for determining an electrical parameter includes charging, in parallel, a first capacitor and a second capacitor from a common supply voltage, measuring a first discharge time by discharging the first capacitor using a comparator and a time-to-digital converter that is connected to an output of the comparator and that provides a digital output signal, measuring a second discharge time by discharging the first capacitor a second time or by discharging the second capacitor using the comparator and the time-to-digital converter and determining the electrical parameter from a ratio of the first and second discharge times.