Capacitor-Less LDO Active Discharge for Transient Stability

The patent introduces an active discharge circuit with a controlled current source as an intermediary component between the output node and ground. This active discharge circuit acts as a mediator that provides controlled current sinking during transient conditions, enabling the capacitor-less LDO to maintain stability without requiring large external capacitors. The active discharge circuit responds to voltage drops at the output node by activating the current source to sink excess current, preventing oscillations and improving transient response.

The patent applies preliminary anti-action by implementing an active discharge circuit that preemptively counters inrush current effects. The controlled current source is configured to activate during supply ramp conditions and sink current in opposition to the inrush current flowing into the output capacitor. This preliminary counter-action prevents excessive inrush currents from damaging the regulator or causing instability, while still allowing fast transient response when load changes occur.

The patent implements dynamics by making the discharge circuit's current sinking capability adjustable and condition-dependent. The controlled current source dynamically modifies its operation based on load conditions, process corners, and temperature. During no-load conditions at extreme process corners and high temperatures, the active discharge circuit reduces its current sinking activity to minimize quiescent current consumption. When load transients occur, the circuit dynamically increases its current sinking capability to maintain stability, thus adapting to different operating conditions optimally.