A Self-Sustained RO Design for Low Power Multimedia Processing Blocks in Mobile Handsets

A typical smart phone has many high speed digital blocks running at a frequency range as high as 200-800 MHz and consumes a lot of power to produce a high clock frequency if a separate crystal mechanism is not used. In order to cater to high speed clock requirement for multimedia blocks inside a handset with a reduced power overhead, this paper proposes a novel self-sustained, self-start and low voltage Ring Oscillator (RO) as a frequency generation block. A unique combination of Direct Current (DC)-DC converter and a RO is proposed to fulfill the needs of high speed, power hungry multimedia digital/analog blocks of the mobile processors both in terms of clock frequency and power transfer. The paper reports a significant reduction in power consumption for a typical RO as well as for the overall combination proposed.