高輕載轉換效率及最小互穩壓特性之單電感多輸出直流-直流轉換器

Abstract

本論文提出可同時提供降壓(buck)及升壓(boost)輸出電源準位並具磁滯模式(hysteresis mode)與負載電流相依式峰值電流控制(load-dependant peak-current control, LDPCC)機制之單電感多輸出直流-直流電源轉換器(single-inductor multi-output converter, SIMO converter)。在LDPCC機制及磁滯(hysteresis)模式的自動調節功能控制之下，各個輸出端的互穩壓(cross regulation)效應可被有效的降低。此外，新發表的壓差產生電路(delta-voltage generator)與功率比較器(power comparator)的控制下，SIMO電源轉換器能平順地在脈寬調變(pulse width modulation, PWM)操作模式與磁滯模式之間切換，故能有效消除當降壓端的輸出功率大於升壓端的輸出功率情形下所產生的電感電流累積效應。本論文所發表的SIMO直流電源轉換器使用了TSMC 0.25μm 2P5M製程來實現驗証晶片的設計。驗証晶片的實驗結果呈現出在磁滯模式下有80%的輕載轉換效率及脈寬調變模式下93%的重載轉換效率，並可得到最小互穩壓效應可減少至0.35%的輸出電壓準位之內。

A load-dependant peak-current control single-inductor multiple-output (SIMO) converter with hysteresis mode is proposed. It includes multiple buck and boost output voltages. Owing to the adaptive adjustment of the load-dependant peak-current control technique and the hysteresis mode, the cross-regulation can be minimized. Furthermore, a new delta-voltage generator can automatically switch the operating mode from pulse width modulation (PWM) mode to hysteresis mode, thereby avoiding inductor current accumulation when the total power of the buck output terminals is larger than that of the boost output terminals. The proposed SIMO converter was fabricated by TSMC 0.25μm 2P5M technology. The experimental results show high conversion efficiency at light loads and small cross-regulation within 0.35%. The power conversion efficiency varies from 80% at light loads to 93% at heavy loads.