93% Power Reduction by Automatic Self Power Gating (ASPG) and Multistage Inverter for Negative Resistance (MINR) in 0.7V, 9.2uW, 39MHz Crystal Oscillator

Introduction Fig. 1 shows a target application of a proposed crystal oscillator (XO). XO must be always powered ON not only in an active mode but also in a stand-by mode. The power reduction of XO is important, because XO dominates the power in the stand-by mode. In the active mode, a low phase noise of XO is required for RF blocks, while the low phase noise is not required in the stand-by mode, because the RF blocks are powered OFF. Therefore, in this paper, a new low power mode of XO with an automatic self power gating (ASPG) is proposed. A multistage inverter for a negative resistance (MINR) is also proposed to reduce the power.