Design Of Reconfigurable Charge Pump With High Performance

With the development of portable electronic products,charge pump stands out from multiple power management circuits due to its inductorless and integratable characteristics.Moreover,charge bump can maintain high energy conversion efficiency with all voltage conversion ratios,thus it is increasingly concerned by scholars and engineers.But there are still some disadvantages existed in charge pump,such as threshold voltage loss,reverse current and fixed voltage conversion ratio.Firstly,according to the structural characteristics and operation principle of charge pump,the main performance parameters and the existing problems of charge pump are analyzed in the paper.Then a charge pump with threshold voltage loss elimination technique and a charge pump with reverse current reduction technique are designed respectively.Lastly,since the charge pump with single voltage conversion ratio adapts to limited range of load or input variations,while traditional reconfigurable charge pump suffers from redundant large-size devices,low utilization rate of devices and low energy density,this paper proposes a new reconfiguration scheme for charge pump.This scheme uses the same number of large-size devices as that of single voltage conversion rate charge pump,to realize a high performance and reconfigurable charge pump with multi-conversion rates,combined with the aforementioned threshold voltage loss elimination technique and reverse current reduction technique.All of the schematics and layouts proposed in this paper are designed based on TSMC 0.18?m process.The simulation results by Cadence's spectre simulation tool show that,the output voltage of the charge pump with threshold voltage loss elimination technique exceeds 97% of the ideal output voltage at empty-load condition,the reverse current of the charge pump with reverse current reduction technique is reduced by 95% compared with conventional charge pump.Furthermore,the reconfigurable charge pump with four conversion ratios can shift conversion ratio among 2X,3X,4X,and 5X.With an input voltage of 1V,the output voltage covers a range of 1.97~4.84 V with energy conversion efficiency of 71%.