Comparator Offset Calibration with Current-Valve Bias Switching

The patent implements a current valve that dynamically adjusts the supply current to the differential amplification circuit based on control signals. During offset calibration mode, the current is increased to provide a wide adjustment range and high resolution. During normal operation mode, the current is reduced to minimize power consumption. This dynamic current control resolves the contradiction between offset calibration accuracy and power consumption.

The patent employs periodic action by separating offset calibration and normal operation into distinct time periods. During calibration period, high supply current provides fine resolution for accurate offset adjustment. During normal operation period, the comparator operates at optimized current for maximum speed. The control signal switches between calibration mode and normal mode, ensuring that high current is applied only when needed for calibration, thus maintaining operating speed while achieving high calibration resolution.

The patent changes the supply current parameter dynamically using a current valve controlled by control signals. The same differential amplification circuit structure achieves different performance levels by adjusting the current parameter: high current during calibration for high accuracy and wide offset adjustment range, low current during normal operation for reduced power consumption and area utilization. This parameter change approach allows the circuit to achieve high accuracy when needed without permanently requiring the larger area and power associated with high-current operation.