Autozeroing Data Converter for Offset-Cancelled Memory Timing

The offset voltage cancellation operation is performed in advance during a calibration phase before normal memory operations begin. The autozeroing circuit pre-cancels offset voltages by storing them in capacitors during initialization, so that subsequent read and write operations do not suffer from timing errors due to offset voltage, thereby maintaining high timing accuracy without slowing down operational throughput

The impedance control calibration circuit operates continuously and independently in parallel with the offset cancellation operation. Both operations are performed simultaneously without interfering with each other, ensuring that the useful actions of offset cancellation and impedance calibration continue without interruption, thereby maintaining high productivity while achieving accurate timing

The offset voltage cancellation function is extracted as a separate autozeroing circuit module with dedicated gain circuits and capacitors, independent from the main memory operation circuits. This modular extraction allows the offset cancellation to be performed with specialized components optimized for this function, improving timing accuracy while containing the complexity increase to a specific module rather than affecting the entire system

The autozeroing circuit with gain circuits and capacitors serves multiple functions: it cancels offset voltages to improve timing accuracy, and simultaneously provides signal amplification through the gain circuits. By making these components multi-functional, the patent reduces the need for separate dedicated circuits, thereby managing device complexity while achieving the desired timing precision