Evaluation of power supply noise reduction by implementing on-chip capacitance

On-chip decoupling capacitor works to reduce on-chip power supply fluctuation by localizing switching current inside chip. This results in the reduction of electromagnetic interference (EMI) by preventing switching current with high frequency components flowing out from the chip. In this paper, a test chip with on-chip decoupling capacitance and noise generating circuits has been reported using CMOS 0.18 μm process. Shoot-through current generator was designed to excite impulse type noise generation. Effects of on-chip capacitance on noise reduction ware evaluated by measuring the test chip as well as by using power supply noise analysis tool. Power supply noise reduction has been quantitatively evaluated by both experiment and analysis.