1V power supply, 384 ks/s 10b A/D and D/A converters with swing-suppression noise shaping

Low-power-consumption circuits for analog-digital mixed LSIs are key to attaining a long battery life and light weight for portable equipment such as digital cordless phones (DCP) and digital audio equipment. CMOS LSI power consumption decreases in proportion to the square of the supply voltage (Vdd). Therefore, the most effective way to minimize power consumption is to reduce Vdd to 1V, the minimum voltage needed for direct one-cell-battery operation. Reported 1V digital circuits operating above 10 Mb/s use a multi-threshold (MT) CMOS circuit that has normal and low-threshold-voltage transistors. However, implementing a 1V analog interface is difficult because of degradation in analog circuit performance. A swing-suppression noise-shaping technique and circuit suitable for operation at 1V or less solves this problem.<>