Embedded DC-DC Voltage Down Converter for Low-Power VLSI Chip

A fully integrated DC-DC voltage down converter (VDC) is proposed. Employing a bias voltage generator and a PMOS pass device with forward-biased source-to-bulk circuit, the architecture of the proposed VDC is simple and can be fabricated by conventional CMOS technology. VDC converts 3.3V to lower voltage so that the internal circuits of VLSI are used. In this paper, 1.8V is used as an experiment vehicle. For a given size of PMOS pass device, the circuit achieves approximately a large output current improvement over its nonforward-biased state. The output voltage of VDC has characteristics such as a temperature dependency of only 0.543mV/degC and a voltage deviation within plusmn0.42% for plusmn10% variation of supply voltage. The output voltage is stabilized with plusmn3.8mV for load current varying from 0 to 100mA