Area-efficient linear regulator with ultra-fast load regulation

We demonstrate a fully integrated linear regulator for multisupply voltage microprocessors implemented in a 90 nm CMOS technology. Ultra-fast single-stage load regulation achieves a 0.54-ns response time at 94% current efficiency. For a 1.2-V input voltage and 0.9-V output voltage the regulator enables a 90 mV_P-P output droop for a 100-mA load step with only a small on-chip decoupling capacitor of 0.6 nF. By using a PMOS pull-up transistor in the output stage we achieved a small regulator area of 0.008 mm² and a minimum dropout voltage of 0.2 V for 100 mA of output current. The area for the 0.6-nF MOS capacitor is 0.090 mm².