All-Digital Adaptive Clocking to Tolerate Transient Supply Noise in a Low-Voltage Operation

Abstract

This paper presents an all-digital technique to modulate the system clock and local clocks in response to global and local voltage noise to prevent timing errors during low-voltage operation. The critical path replica circuits are utilized to change the clock period within a clock cycle in response to transient supply noise. Measurement in 130-nm CMOS demonstrates reliable operation of a test pipeline over a wide dc (1.3-0.74 V) voltage range. At 0.81 V, the pipeline operates without timing errors at 7.2% higher frequency even under a 189-mV transient voltage droop.