Patent ID: 7405688

Claim:
An analog-to-digital converter, comprising: a window-comparator comprising an input for an analog input signal and an output for a comparison result indicating a result of a comparison of the analog input signal with an upper bound and a lower bound of a level window; a level window position signal generator, the level window position signal generator comprising a window position control input coupled, directly or via a control logic, to the output for the comparison result, and an output for a level window position signal adjusting a position of the level window based on information derived from the comparison result and indicating whether the level window should be increased, decreased or maintained, wherein the level window position signal generator comprises an analog integrator, the analog integrator comprising a controlled current source and a capacitor, wherein the controlled current source is configured to provide a current for charging the capacitor, for discharging the capacitor or for leaving the charge of the capacitor unchanged, in dependence on the comparison result, wherein the voltage of the capacitor is used to provide the level window position signal, wherein the level window position signal increases the position of the level window, if the comparison result indicates that the level of the input signal is above the upper bound of the level window, wherein the level window position signal decreases the position of the level window, if the comparison result indicated that the level of the input signal is below the lower bound of the level window, and wherein the level window position signal leaves the position of the level window unchanged, if the comparison result indicates that the level of the input signal is between the lower bound of the level window and the upper bound of the level window; an output for digital information based on the comparison result; and a counter, the counter comprising a count-up/count-down control input coupled, directly or via a control logic, to the output for the comparison result, and a counter state interface for the digital information.