Differential Amplifier Switching Scheme for Offset-Free Output

The patent applies preliminary action by performing offset sampling before the main signal amplification. The auto-zero circuit samples the offset voltage at a specific timing (when input terminals are connected to reference potentials) and stores it in a capacitor. This sampled offset is then subtracted from the amplified signal output, effectively removing the offset error. The control circuit generates timing signals to coordinate the sampling phase and amplification phase, ensuring the offset is compensated before the final output is produced.

The patent merges the offset compensation function with the signal amplification function in a single differential amplifier circuit. The auto-zero circuit shares the same amplifier core, and the switching network integrates multiple functions: connecting input terminals to reference potentials for offset sampling, connecting to ground for discharging capacitors, and enabling normal signal amplification. The control circuit generates multiple timing signals that coordinate these different operational phases, allowing one circuit to perform both offset compensation and signal amplification without requiring separate dedicated circuits.

The switching network in the patent is designed with multi-functionality to reduce overall complexity. The same switches are used for multiple purposes: connecting input terminals to reference potentials during offset sampling, connecting to ground for discharging capacitors, and enabling normal signal amplification during operation. The control circuit generates timing signals that coordinate these different operational phases, allowing a single switching network to perform what would otherwise require multiple separate switching circuits. This universal approach reduces the total number of components while achieving effective offset compensation.