20.Automatic Substrate Switching Circuit for On-Chip Adaptive Power-Supply System资料.pdfVIP

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS—II: EXPRESS BRIEFS, VOL. 54, NO. 7, JULY 2007 641 Automatic Substrate Switching Circuit for On-Chip Adaptive Power-Supply System Dongsheng Ma, Member, IEEE Abstract— In energy-aggressive dynamic voltage scaling tech- low supply voltage will cause a long delay time and make the niques, adaptive on-chip power supply, which can provide variable circuit miss the computation deadline. The error rate will thus voltage in a wide range, is highly demanded. However, potential increase beyond the reference and a higher output voltage will leakage and latch-up problems arise, when the substrate biasing be generated by the power converter to decrease the error rate. voltages of the transistors vary with the supply voltage. An auto- matic substrate switching circuit (ASSC) is thus presented in this An enabling technology for the DVS techniques is the design of paper, with accurate voltage comparison, fast transient response adjustable and variable on-chip dc–dc power supplies [5]–[7], and small silicon area. Experimental results show that the circuit which provides new control freedom for low-power VLSI automatically and accurately switches 1.3-nF pMOS substrate at systems. The most desirable feature of these power supplies a switching speed of 1.1 V/ s, with a switching voltage range of is that the supply can step up and down for different voltage 1.1 to 3.3 V. The tracking error in steady state is below 18 mV. levels. Hence, a noninverting step-up/down switching dc–dc Fabricated in a standard 0.35- m n-well digital CMOS process, the ASSC