Circuit-Level Design of a Power Supply Unit with Extra Low-Noise Output for Portable Integrated SoCs
Switch-mode voltage regulators are considered as the dominant choice for low-power integrated power supplies. Employing the advantages of a switch-mode voltage regulator in 0.18um CMOS technology, a power supply has been designed for a complete System-on-Chip (SoC). While offering enough drive capability for the entire system, the supply provides an extra highly-regulated output for noise-sensitive analog blocks. At first, a front-end buck regulator converts the time-variant unregulated input voltage to an initially-regulated general voltage. To further regulate this voltage for noise-sensitive blocks, a new continuous-time buffered voltage source has been added to the circuit.