LDO Feed-Forward Ripple Cancellation for Higher PSRR

The patent applies preliminary action by introducing a feed-forward ripple cancellation path that anticipates and cancels supply voltage ripples before they affect the output. The capacitor C1 is connected to detect supply ripples in advance, and the circuit generates a compensating signal to cancel these ripples before they reach the power transistor, thereby improving PSRR without requiring complex feedback mechanisms

The patent uses an intermediary approach by introducing a ripple cancellation current path that acts as a mediator between the supply voltage and the power transistor. The capacitor C1 and associated transistors create an intermediate signal path that generates a compensating current to counteract supply ripples, effectively isolating the output from input disturbances without directly modifying the power transistor itself

The patent applies local quality by focusing the ripple cancellation function in a specific localized circuit section rather than redesigning the entire LDO regulator. The capacitor C1 and its associated transistors form a dedicated ripple cancellation module that operates independently, providing targeted PSRR improvement without requiring complex changes throughout the entire circuit

The patent merges the ripple cancellation function with the existing LDO regulator architecture by integrating the feed-forward path into the current regulation mechanism. The compensating current generated by the ripple cancellation circuit is combined with the main regulation current, allowing both functions to work together through shared circuit elements rather than requiring completely separate systems